Slow Like Wiki - User contributions [en]

Films

2026-02-20T20:59:05Z

Rob: /* 2026 */

== Films to Watch ==

[https://www.cinealcazar.fr/fichier/programme.pdf Cinema Alcazar Program]

* Three Amigos (on Netflix)
* Event Horizon (on Netflix)
* Mind trips
** Triangle
** Beyond the infinite two minutes
** Enemy
** Under the Silver Lake
** The Vanishing
** Angel Heart
** Following
** The Invisible Guest
** Perfect Blue
** Resolution
* fast times
* the Jerk
* Mutiny on the Bounty
* Entrapment
* Mask of Zorro
* PTA - Hard Eight, Magnolia, Boogie Nights, etc
* Little Big and Far - weird scandinavian film
* the Fisher King
* This is Spinal tap
* Big Night - Tucci and Shaloub
* Punch drunk love
* Boyhood
* Kind hearts and coronets
* A night at the opera
* Blazing saddles
* Lives of others
* Lost in Translation
* One flew over
* Get out
* Maltese falcon
* Early mad maxes
* Joule of the Nile
* the man with two brains
* Psycho Therapy - Steve Buscemi is a serial killer who wants to advise an author, but ends up playing a marriage counselor.
* Early Steve Martin
* A Complete Unknown
* la La Land -
* The Phoenician Scheme - new Wes Anderson comedy espionage thriller
* Thelma - Grandma fights con artists
* Kinds of Kindness
* 2001
* The Elephant Man
* The Fabulous Baker Boys
* Network

== Films Watched ==

=== 2026 ===

* 14. The Mastermind
* 13. The Birdcage
* 12. Fight Club (rewatch)
* 11. Knives Out: Glass Onion (rewatch)
* 10. Twins
* 9. The Remains of the Day
* 8. The Ladykillers
* 7. Us (rewatch)
* 6. Saving Private Ryan (rewatch)
* 5. Event Horizon
* 4. Insomnia (2002) - Christopher Nolan (rewatch)
* 3. Knives Out (rewatch)
* 2. Gattaca (1997) - Andrew Niccol
* 1. Eddington (2025) - Ari Aster

=== 2025 ===
* 65. Wake Up Dead Man (Knives Out 3)
* 64. Miller's Crossing
* 63. Blood Simple
* 62. Crazy Stupid Love
* 61. Happiest Season
* 60. Bridge of Spies
* 59. Identity
* 58. Clueless
* 57. Ace Ventura 2: Call of Nature
* 56. Master and Commander: The Far Side of the World
* 55. Apollo 13
* 54. LA Confidential (rewatch)
* 53. Inside Llewyn Davis
* 52. M3gan
* 51. Clear and Present Danger
* 50. 12 Monkeys
* 49. No Country for Old Men
* 48. The Hudsucker Proxy
* 47. La Cuisse ou l'aile
* 46. Mission Impossible : The Final Reckoning
* 45. Dumb and Dumber
* 44. Rear Window
* 43. Raising Arizona
* 42. Tenet (rewatch)
* 41. The fifth Element
* 40. Burn Without Reading
* 39. The Big Lebowski (rewatch)
* 38. Fargo (rewatch)
* 37. 28 Days Later (rewatch)
* 36. O Brother, Where Art Thou
* 35. Mickey 17
* 34. Empire of the Sun
* 33. The Fugitive
* 32. Wet Hot American Summer (rewatch)
* 31. Ted
* 30. Hundreds of Beavers
* 29. Wayne’s World (rewatch)
* 28. True Grit (Coen Bros)
* 27. Groundhog Day (rewatch)
* 26. Moonrise Kingdom
* 25. Asterix et Obelix: Mission Cleopatra
* 24. Adaptation (rewatch)
* 23. Romancing the Stone (rewatch)
* Easter Film Festival
** 22. Mad Max: Fury Road (rewatch)
** 21. Witness
** 20. The Grand Budapest Hotel (rewatch)
** 19. Conclave
** 18. Ace Ventura: Pet Detective
** 17. Lincoln
** 16. Being John Malkovitch (rewatch)
** 15. AI (rewatch)
** 14. The Royal Tenenbaums (rewatch)
** 13. Total Recall 1990 (rewatch)
** 12. In the Line of Fire (rewatch)
* 11. Flow
* 10. Juror No. 2
* 9. The Savage Robot
* 8. Eternal Sunshine of the Spotless Mind (rewatch)
* 7. Dead Poet's Society
* 6. Notting Hill (rewatch)
* 5. My Neighbor Totoro (rewatch)
* 4. Kiki’s Delivery Service (rewatch)
* 3. Dr Strangelove (rewatch)
* 2. Dune 2
* 1. Austin Powers: The Spy who Shagged Me (rewatch)

=== 2024 and Earlier ===
* The Big Lebowski
* The Holiday
* Love Actually
* Bill and Ted's Excellent Adventure
* The Mask
[[Category:Films]]

Films

2026-01-27T20:22:52Z

Rob: /* 2026 */

== Films to Watch ==

[https://www.cinealcazar.fr/fichier/programme.pdf Cinema Alcazar Program]

* Three Amigos (on Netflix)
* Event Horizon (on Netflix)
* Mind trips
** Triangle
** Beyond the infinite two minutes
** Enemy
** Under the Silver Lake
** The Vanishing
** Angel Heart
** Following
** The Invisible Guest
** Perfect Blue
** Resolution
* fast times
* the Jerk
* Mutiny on the Bounty
* Entrapment
* Mask of Zorro
* PTA - Hard Eight, Magnolia, Boogie Nights, etc
* Little Big and Far - weird scandinavian film
* the Fisher King
* This is Spinal tap
* Big Night - Tucci and Shaloub
* Punch drunk love
* Boyhood
* Kind hearts and coronets
* A night at the opera
* Blazing saddles
* Lives of others
* Lost in Translation
* One flew over
* Get out
* Maltese falcon
* Early mad maxes
* Joule of the Nile
* the man with two brains
* Psycho Therapy - Steve Buscemi is a serial killer who wants to advise an author, but ends up playing a marriage counselor.
* Early Steve Martin
* A Complete Unknown
* la La Land -
* The Phoenician Scheme - new Wes Anderson comedy espionage thriller
* Thelma - Grandma fights con artists
* Kinds of Kindness
* 2001
* The Elephant Man
* The Fabulous Baker Boys
* Network

== Films Watched ==

=== 2026 ===

* 11. Knives Out: Glass Onion
* 10. Twins
* 9. The Remains of the Day
* 8. the Ladykillers
* 7. Us
* 6. Saving Private Ryan
* 5. Event Horizon
* 4. Insomnia (2002) - Christopher Nolan
* 3. Knives Out
* 2. Gattaca (1997) - Andrew Niccol
* 1. Eddington (2025) - Ari Aster

=== 2025 ===
* 65. Wake Up Dead Man (Knives Out 3)
* 64. Miller's Crossing
* 63. Blood Simple
* 62. Crazy Stupid Love
* 61. Happiest Season
* 60. Bridge of Spies
* 59. Identity
* 58. Clueless
* 57. Ace Ventura 2: Call of Nature
* 56. Master and Commander: The Far Side of the World
* 55. Apollo 13
* 54. LA Confidential (rewatch)
* 53. Inside Llewyn Davis
* 52. M3gan
* 51. Clear and Present Danger
* 50. 12 Monkeys
* 49. No Country for Old Men
* 48. The Hudsucker Proxy
* 47. La Cuisse ou l'aile
* 46. Mission Impossible : The Final Reckoning
* 45. Dumb and Dumber
* 44. Rear Window
* 43. Raising Arizona
* 42. Tenet (rewatch)
* 41. The fifth Element
* 40. Burn Without Reading
* 39. The Big Lebowski (rewatch)
* 38. Fargo (rewatch)
* 37. 28 Days Later (rewatch)
* 36. O Brother, Where Art Thou
* 35. Mickey 17
* 34. Empire of the Sun
* 33. The Fugitive
* 32. Wet Hot American Summer (rewatch)
* 31. Ted
* 30. Hundreds of Beavers
* 29. Wayne’s World (rewatch)
* 28. True Grit (Coen Bros)
* 27. Groundhog Day (rewatch)
* 26. Moonrise Kingdom
* 25. Asterix et Obelix: Mission Cleopatra
* 24. Adaptation (rewatch)
* 23. Romancing the Stone (rewatch)
* Easter Film Festival
** 22. Mad Max: Fury Road (rewatch)
** 21. Witness
** 20. The Grand Budapest Hotel (rewatch)
** 19. Conclave
** 18. Ace Ventura: Pet Detective
** 17. Lincoln
** 16. Being John Malkovitch (rewatch)
** 15. AI (rewatch)
** 14. The Royal Tenenbaums (rewatch)
** 13. Total Recall 1990 (rewatch)
** 12. In the Line of Fire (rewatch)
* 11. Flow
* 10. Juror No. 2
* 9. The Savage Robot
* 8. Eternal Sunshine of the Spotless Mind (rewatch)
* 7. Dead Poet's Society
* 6. Notting Hill (rewatch)
* 5. My Neighbor Totoro (rewatch)
* 4. Kiki’s Delivery Service (rewatch)
* 3. Dr Strangelove (rewatch)
* 2. Dune 2
* 1. Austin Powers: The Spy who Shagged Me (rewatch)

=== 2024 and Earlier ===
* The Big Lebowski
* The Holiday
* Love Actually
* Bill and Ted's Excellent Adventure
* The Mask
[[Category:Films]]

Films

2026-01-20T21:00:28Z

Rob: /* 2026 */

== Films to Watch ==

[https://www.cinealcazar.fr/fichier/programme.pdf Cinema Alcazar Program]

* Three Amigos (on Netflix)
* Event Horizon (on Netflix)
* Mind trips
** Triangle
** Beyond the infinite two minutes
** Enemy
** Under the Silver Lake
** The Vanishing
** Angel Heart
** Following
** The Invisible Guest
** Perfect Blue
** Resolution
* fast times
* the Jerk
* Mutiny on the Bounty
* Entrapment
* Mask of Zorro
* PTA - Hard Eight, Magnolia, Boogie Nights, etc
* Little Big and Far - weird scandinavian film
* the Fisher King
* This is Spinal tap
* Big Night - Tucci and Shaloub
* Punch drunk love
* Boyhood
* Kind hearts and coronets
* A night at the opera
* Blazing saddles
* Lives of others
* Lost in Translation
* One flew over
* Get out
* Maltese falcon
* Early mad maxes
* Joule of the Nile
* the man with two brains
* Psycho Therapy - Steve Buscemi is a serial killer who wants to advise an author, but ends up playing a marriage counselor.
* Early Steve Martin
* A Complete Unknown
* la La Land -
* The Phoenician Scheme - new Wes Anderson comedy espionage thriller
* Thelma - Grandma fights con artists
* Kinds of Kindness
* 2001
* The Elephant Man
* The Fabulous Baker Boys
* Network

== Films Watched ==

=== 2026 ===

* 8. The Remains of the Day
* 7. the Ladykillers
* 6. Us
* 5. Saving Private Ryan
* 4. Event Horizon
* 3. Insomnia (2002) - Christopher Nolan
* 2. Gattaca (1997) - Andrew Niccol
* 1. Eddington (2025) - Ari Aster

=== 2025 ===
* 65. Wake Up Dead Man (Knives Out 3)
* 64. Miller's Crossing
* 63. Blood Simple
* 62. Crazy Stupid Love
* 61. Happiest Season
* 60. Bridge of Spies
* 59. Identity
* 58. Clueless
* 57. Ace Ventura 2: Call of Nature
* 56. Master and Commander: The Far Side of the World
* 55. Apollo 13
* 54. LA Confidential (rewatch)
* 53. Inside Llewyn Davis
* 52. M3gan
* 51. Clear and Present Danger
* 50. 12 Monkeys
* 49. No Country for Old Men
* 48. The Hudsucker Proxy
* 47. La Cuisse ou l'aile
* 46. Mission Impossible : The Final Reckoning
* 45. Dumb and Dumber
* 44. Rear Window
* 43. Raising Arizona
* 42. Tenet (rewatch)
* 41. The fifth Element
* 40. Burn Without Reading
* 39. The Big Lebowski (rewatch)
* 38. Fargo (rewatch)
* 37. 28 Days Later (rewatch)
* 36. O Brother, Where Art Thou
* 35. Mickey 17
* 34. Empire of the Sun
* 33. The Fugitive
* 32. Wet Hot American Summer (rewatch)
* 31. Ted
* 30. Hundreds of Beavers
* 29. Wayne’s World (rewatch)
* 28. True Grit (Coen Bros)
* 27. Groundhog Day (rewatch)
* 26. Moonrise Kingdom
* 25. Asterix et Obelix: Mission Cleopatra
* 24. Adaptation (rewatch)
* 23. Romancing the Stone (rewatch)
* Easter Film Festival
** 22. Mad Max: Fury Road (rewatch)
** 21. Witness
** 20. The Grand Budapest Hotel (rewatch)
** 19. Conclave
** 18. Ace Ventura: Pet Detective
** 17. Lincoln
** 16. Being John Malkovitch (rewatch)
** 15. AI (rewatch)
** 14. The Royal Tenenbaums (rewatch)
** 13. Total Recall 1990 (rewatch)
** 12. In the Line of Fire (rewatch)
* 11. Flow
* 10. Juror No. 2
* 9. The Savage Robot
* 8. Eternal Sunshine of the Spotless Mind (rewatch)
* 7. Dead Poet's Society
* 6. Notting Hill (rewatch)
* 5. My Neighbor Totoro (rewatch)
* 4. Kiki’s Delivery Service (rewatch)
* 3. Dr Strangelove (rewatch)
* 2. Dune 2
* 1. Austin Powers: The Spy who Shagged Me (rewatch)

=== 2024 and Earlier ===
* The Big Lebowski
* The Holiday
* Love Actually
* Bill and Ted's Excellent Adventure
* The Mask
[[Category:Films]]

Films

2026-01-17T21:14:21Z

Rob: /* 2026 */

== Films to Watch ==

[https://www.cinealcazar.fr/fichier/programme.pdf Cinema Alcazar Program]

* Three Amigos (on Netflix)
* Event Horizon (on Netflix)
* Mind trips
** Triangle
** Beyond the infinite two minutes
** Enemy
** Under the Silver Lake
** The Vanishing
** Angel Heart
** Following
** The Invisible Guest
** Perfect Blue
** Resolution
* fast times
* the Jerk
* Mutiny on the Bounty
* Entrapment
* Mask of Zorro
* PTA - Hard Eight, Magnolia, Boogie Nights, etc
* Little Big and Far - weird scandinavian film
* the Fisher King
* This is Spinal tap
* Big Night - Tucci and Shaloub
* Punch drunk love
* Boyhood
* Kind hearts and coronets
* A night at the opera
* Blazing saddles
* Lives of others
* Lost in Translation
* One flew over
* Get out
* Maltese falcon
* Early mad maxes
* Joule of the Nile
* the man with two brains
* Psycho Therapy - Steve Buscemi is a serial killer who wants to advise an author, but ends up playing a marriage counselor.
* Early Steve Martin
* A Complete Unknown
* la La Land -
* The Phoenician Scheme - new Wes Anderson comedy espionage thriller
* Thelma - Grandma fights con artists
* Kinds of Kindness
* 2001
* The Elephant Man
* The Fabulous Baker Boys
* Network

== Films Watched ==

=== 2026 ===

* 6. Us
* 5. Saving Private Ryan
* 4. Event Horizon
* 3. Insomnia (2002) - Christopher Nolan
* 2. Gattaca (1997) - Andrew Niccol
* 1. Eddington (2025) - Ari Aster

=== 2025 ===
* 65. Wake Up Dead Man (Knives Out 3)
* 64. Miller's Crossing
* 63. Blood Simple
* 62. Crazy Stupid Love
* 61. Happiest Season
* 60. Bridge of Spies
* 59. Identity
* 58. Clueless
* 57. Ace Ventura 2: Call of Nature
* 56. Master and Commander: The Far Side of the World
* 55. Apollo 13
* 54. LA Confidential (rewatch)
* 53. Inside Llewyn Davis
* 52. M3gan
* 51. Clear and Present Danger
* 50. 12 Monkeys
* 49. No Country for Old Men
* 48. The Hudsucker Proxy
* 47. La Cuisse ou l'aile
* 46. Mission Impossible : The Final Reckoning
* 45. Dumb and Dumber
* 44. Rear Window
* 43. Raising Arizona
* 42. Tenet (rewatch)
* 41. The fifth Element
* 40. Burn Without Reading
* 39. The Big Lebowski (rewatch)
* 38. Fargo (rewatch)
* 37. 28 Days Later (rewatch)
* 36. O Brother, Where Art Thou
* 35. Mickey 17
* 34. Empire of the Sun
* 33. The Fugitive
* 32. Wet Hot American Summer (rewatch)
* 31. Ted
* 30. Hundreds of Beavers
* 29. Wayne’s World (rewatch)
* 28. True Grit (Coen Bros)
* 27. Groundhog Day (rewatch)
* 26. Moonrise Kingdom
* 25. Asterix et Obelix: Mission Cleopatra
* 24. Adaptation (rewatch)
* 23. Romancing the Stone (rewatch)
* Easter Film Festival
** 22. Mad Max: Fury Road (rewatch)
** 21. Witness
** 20. The Grand Budapest Hotel (rewatch)
** 19. Conclave
** 18. Ace Ventura: Pet Detective
** 17. Lincoln
** 16. Being John Malkovitch (rewatch)
** 15. AI (rewatch)
** 14. The Royal Tenenbaums (rewatch)
** 13. Total Recall 1990 (rewatch)
** 12. In the Line of Fire (rewatch)
* 11. Flow
* 10. Juror No. 2
* 9. The Savage Robot
* 8. Eternal Sunshine of the Spotless Mind (rewatch)
* 7. Dead Poet's Society
* 6. Notting Hill (rewatch)
* 5. My Neighbor Totoro (rewatch)
* 4. Kiki’s Delivery Service (rewatch)
* 3. Dr Strangelove (rewatch)
* 2. Dune 2
* 1. Austin Powers: The Spy who Shagged Me (rewatch)

=== 2024 and Earlier ===
* The Big Lebowski
* The Holiday
* Love Actually
* Bill and Ted's Excellent Adventure
* The Mask
[[Category:Films]]

A Brief History of Intelligence

2025-04-21T15:55:25Z

Rob: /* ChatGPT */

== Summary ==
This was a perfect book for me to read at this moment, giving me insights into both the evolution of the brain and also AI learning methods, and I'll use his list of the five "breakthroughs" as the initial structure for my analysis:
* 600m ya - Bilaterians and Steering
* 500m ya - Vertebrates and Reinforcing
* 200m ya - Mammals and Simulation
* 15m ya - Primates and Metathinking
* 100k ya - Humans and Speech
== 600m ya - Bilaterians and Steering ==

=== Valence ===

* Bilaterians are the only animals that have brains
* Nematodes (legless wormlike creatures about the size of a grain of rice) emerge in the Edicaran period from 635 to 539m ya.
* Brain had 302 neurons (against 85 billion today
* Initial steering is obtained through assessing the valence (goodness or badness) of a stimulus, and going towards the things that smelled good and away from the things that smelled bad.
* There were negative and positive valence sensing neurons and move forward neurons and turning neurons.
* The various sensory inputs acted as votes for going one way or another and the first brains evolved as a mega-integration place to take in all these votes and then decide who had won and thus where to steer.

=== Emotions ===

* Affect is the name for the unifying foundation of emotions
* In addition to valance (good or bad), there is arousal (high or low)
* A primitive good mood encourages feeding, digesting, and sexual activity
* A primitive bad mood inhibits these activities
* An aroused good mood leads to exploiting nearby food sources or sexual partners
* An aroused bad mood leads to escaping from bad feelings - hunger, fear
* The brain generates affective states using neuromodulators like dopanmine and serotonin.
* In the nematode, dopamine is released to create arousal and drive the search for food and serotonin is released to suppress arousal and drive the enjoyment of digesting it.
* Dopamine is less about liking things and more about wanting them.
* Other neuromodulators - norepinephrine, octopamine, and epinephrine drive escape behavior by suppressing the effectiveness of serotonin and stopping an animal from being able to rest and feel safe - acute stress response.
* Opioids initiate recovery processes and inhibit negative valence neurons to stop and recover from stress episodes.
* Chronic stress turns off arousal and motivation, activates serotonin and leads to numbness and depression (anhedonia). It can cause learned helplessness
* Affect answers two questions:
** Do I want to expend energy by moving?
** Do I want to stay here or leave?
=== Associating, Predicting, Learning ===

* The digestive organs are under the control of the nervous system
* Conditional reactions are involuntary associations - associative learning happens automatically without conscious involvement.
* At the same time as valence, the ability to use experience to change what is considered good and bad also emerges.
* Learning in biological brains has always been continual.
* Pavlov’s conditional reflexes are always strengthening (acquisition) or weakening (extinction) with each new experience. Extinction may be followed by spontaneous recovery (instantaneous) or reacquisition (faster than first time)
* Spontaneous recovery is a primitive form of long-term memory.
* The credit assignment problem - which cue really predicted something subsequently happening?:
** Eligibility traces - Immediately follows cue
** Overshadowing - Pick strongest cue
** Latent inhibition - Pick the cue you haven’t seen before.
** Blocking - Use existing cues and ignore others.
* Learning occurs when synapses change strength or when new ones are formed or old ones are removed.
* Association, prediction, and learning emerged to tweak the goodness and badness of things

== 500m ya - Vertebrates and Reinforcing ==

=== Reinforcement Learning ===
* Cambrian period (Cambrian Explosion) is 540-485m ya.
* The brains of all vertebrates, from fish to humans, develop in the same initial steps:
** Brains differentiate into three bulbs - a forebrain, midbrain, and hindbrain
** The forebrain unfolds into two subsystems:
*** The cortex and the basal ganglia
*** The thalamus and the hypothalamus
* Animals learn by first performing random exploratory actions and then adjusting future actions based on valence outcomes.
* Reinforcement learning is the ability to learn arbitrary sequences of actions through trial and error with reinforcing and punishing depending on the valence outcomes.

=== Temporal Distance Learning ===
* Most drugs of abuse - alcohol, cocaine, nicotine - work by triggering the release of dopamine. All vertebrates, from fish to rats to monkeys to humans, are susceptible to becoming addicted to such dopamine-enhancing chemicals.
* Discounting drives AI systems (or animals) to choose actions that lead to rewards sooner rather than later.
* Dopamine is not a signal for reward but for reinforcement. Reinforcement and reward must be decoupled for reinforcement learning to work. To solve the temporal credit assignment problem, brains must reinforce behaviors based on changes in predicated future rewards, not actual rewards. This is why animals get addicted to dopamine-releasing behaviors despite it not being pleasurable, and this is why dopamine responses quickly shift their activations to the moments when animals predict upcoming reward and away from rewards themselves.
* Dopamine was originally a signal for good things nearby - a primitive version of wanting. Evolution reshaped it into a temporal difference learning signal, from a fuzzy average of recently detected food to an ever fluctuating, precisely measured, and meticulously computed predicted-future-reward signal.
* Disappointment and relief are emergent properties of a brain designed to learn by predicting future rewards.
* The omission of an expected punishment is itself reinforcing; it is relieving. And the omission of an expected reward is itself punishing; it is disappointing.
* Vertebrates are unique in the precision with which they can measure time.
* Temporal distance learning, disappointment, relief, and the perception of time are all related.
* The basal ganglia is in a perpetual state of gating and ungating specific actions, operating as a global puppeteer of an animal's behavior.
** It learns to repeat actions that maximize dopamine release.
** It is a system designed to repeat behaviors that lead to reinforcement and inhibit behaviors that lead to punishment.
* The hypothalamus houses valence neurons inherited from the valence sensory apparatus of ancestral bilaterians.
** It is, in principle, a more sophisticated version of the steering brain of early bilaterians; it reduces external stimuli to good and bad and triggers reflexive responses to each.
** When the hypothalamus is happy, it floods the basal ganglia with dopamine, and when it is upset, it deprives the basal ganglia of dopamine.
** The basal ganglia is a student, always trying to satisfy its vague but stern hypothalamic judge.
** The hypothalamus is the decider of actual rewards.
* How is dopamine transformed from a valence signal for actual rewards to a temporal difference signal for changes in predicted future reward? The basal ganglian student initially learns solely from the hypothalamic judge, but over time learns to judge itself, knowing when it makes a mistake before the hypothalamus gives any feedback.
* This is why dopamine neurons initially respond when rewards are delivered, but over time shift their activation toward predictive cues.
* This is also why receiving a reward that you knew you were going to receive doesn't trigger dopamine release; predictions from the basal ganglia cancel out the excitement from the hypothalamus.

=== Pattern Recognition ===
* Sometime around 500m ya, our ancestor evolve pattern recognition to remember the smell of that dangerous arthropod, to remember the sight of its eyes peeking through the sand.
* Early vertebrates could recognize things using brain structures that decoded patterns of neurons. Within a small mosaic of only fifty typos of olfactory neurons lived a universe of different patterns that could be recognized. Fifty cells can represent over one hundred trillion patterns.
* Patterns can be similar but not the same.
* Your iPhone needs to be able to tell the difference between your face and other people's faces, despite the fact that faces have overlapping features (discrimination). It must also be able to identify your face despite changes in shading, angle, facial hair, and more (generalization).
* In the first cortex evolved a new morphology of neuron:
** Pyramidal neurons have hundreds of dendrites and receive inputs across thousands of synapses.
** These were the first neurons designed for the purpose of recognizing patterns.
** A small number of olfactory neurons connect to a much larger number of cortical neurons. They connect sparsely - a given olfactory cell will connect to only a subset of these cortical cells. This leads to pattern separation, decorrelation, or orthogonalization.
* The problem of "catastrophic forgetting is why we don't let AI systems learn things sequentially; they learn things all at once and then stop learning. But even early bilaterians learned continually.
* The retina contains over 100m neurons of five different types. The visual cortex decodes and memorizes the visual pattern the same way the olfactory cortex decodes and memorizes smell patterns.
* But the same visual object can activate different patterns depending on its rotation distance, or location in your visual field. This creates the invariance problem - how to recognize a pattern as the same despite large variance in its inputs.
* The same issue arises with words spoken by a child and an adult or in different accents. Your brain is somehow recognizing a common pattern despite huge variances in the sensory input.
* Visual (and audio) processing in mammals is hierarchical:
** The [https://en.wikipedia.org/wiki/Lateral_geniculate_nucleus lateral geniculate nucleus] (LGN) is a small, ovoid, ventral projection of the thalamus where the thalamus connects with the optic nerve.
** The V1 area decomposes the complex pattens of visual input into simpler features like lines and edges
** V1 sends its output to V2, which then sends information to an area called V4, both of which are sensitive to more complex shapes and objects
** V4 sends its output to the [https://en.wikipedia.org/wiki/Inferior_temporal_gyrus inferior temporal gyrus] or IT cortex, which is sensitive to complex whole objects like specific faces.
* In the predatory arms race of the Cambrian, evolution shifted from arming animals with new sensory neurons for detecting specific things to general mechanisms for recognizing anything, and this caused new sensory organs and each incremental improvement in the brain's pattern recognition expanded the benefits to be gained by having more detailed sensory organs:
** Noses evolved to detect chemicals
** Inner ears evolved to detect frequencies of sound
** Eyes evolved to detect sights
* In the brain, the result was the vertebrate cortex, which somehow recognizes patterns without supervision, accurately discriminates overlapping patterns and generalizes patterns to new experiences. It somehow continually learns patterns without catastrophic forgetting and despite larges variances in its inputs.
* Pattern recognition and reinforcement learning evolved simultaneously in evolution. The greater the brain's ability to kearn arbitrary actions in response to things in the world, the greater the benefit to be gained from recognizing more things in the world. The more unique objects and places a brain can recognize, the more unique actions it can learn to take.
* And so the cortex, basal ganglia, and sensory organs evolved together, all emerging from the same machinations of reinforcement learning.

=== Curiosity ===
* It was early vertebrates that first became curious.
* In vertebrates, surprise itself triggers the release of dopamine, even if there is no "real" reward.
* To make animals curious, we evolved to find surprising and novel things reinforcing, which drives us to pursue and explore them. Even if the reward of an activity is negative, if it is novel, we might pursue it anyway.
* Games of gambling are designed to exploit this with a 48% chance of winning it is high enough to be possible, but uncertain enough to make it surprising.
* Social networks also hack into our 500m year preference for surprise, by showing us surprising things, but only sometimes.
* Curiosity is a requirement for reinforcement learning to work. For the first time, learning became, in and of itself, an extremely valuable activity.

=== Modeling the World ===
* Your brain has built a spatial map of your home so that you can make your way around (with a few stubbed toes) in the dark.
* All vertebrates can learn spatial maps, but simple bilaterians cannot.
* The vestibular sense feels the direction of head movement through "head-direction neurons".
* The cortex of early vertebrates had three subareas:
** Lateral cortex - Recognizes smells and will evolve into the olfactory cortex in early mammals.
** Ventral cortex - Recognizes patterns of sights and sounds and will evolve into the amygdala.
** Medial cortex - Visual, vestibular, and head direction signals propagate here, where they are mixed together and converted into a spatial map. Later became the hippocampus. Contains place cells that activate when an animal is in a specific location
* This was the first time that an organism could recognize where it was.
* The first time a brain differentiated the self from the world.
* The first tiem that a brain constructed an internal model - a representation of the external world.

== 200m ya - Mammals and Simulation ==

=== The Devonian and Permian Eras ===
* 420m to 375m ya is called the Devonian period - arthropods walked out of the oceans to populate the land, plants first evolved leaves for better absorption of sunlight and seeds for spreading, and trees first developed.
* The Late Devonian Extinction caused the Carbon dioxide levels to plummet and the climate to cool, freezing the oceans.
* Reptiles and therapsids evolved, with the therapsids (our ancestors) developing warm-bloodedness - the ability to use energy to generate their own internal heat. During the Permian era (300-250m ya) they became the most successful land animals
* During the Permian-Triassic mass extinction event, 250m ya, over the course of 5-10m years, 96% of all marine life and 70 of land life died.
* The reptiles became dominant while the bigger therapsids died out and only small therapsids, like the cynodont survived.
* These burrowing or arboreal four-inch mammals, like birds or squirrels, had one advantage, they could make the first move.
* The neocortex evolved to give these mammals the ability to simulate actions before they occurred.
* Early vertebrates learned by doing, while these mammals could learn before doing, by imagining.
* There were two requirements needed for simulation to evolve:
** Far-ranging vision - To see much of your surrounding and simulate various paths through them
** Warm-bloodedness - To let mammal brains operate much faster than fish or reptile brains.
* The ventral cortex of the vertebrates became the associative amygdala in mammals - learning to recognize patterns that were predictive of valence outcomes

=== Generative Models, Perception, and the Neocortex ===
* The neocortex is a sheet about two to four millimeters thick, folded around the outside of the brain. Unfolded, it is about three square feet
* There are regions for vision, audition, touch, pain, and taste, for movement, language, and music.
* In the middle of the 20th century, Vernon Mountcastle discovered that the neocortex is made up of repeating and duplicated microcircuits that he called neocortical columns:
** Neurons within a vertical column about five hundred microns in diameter of the neocortical sheet seem to all respond similarly to sensory stimuli, while neurons horizontally farther away do not. Eg an individual column in the visual cortex might contain neurons that all similarly responded to bars of light at specific orientations at a specific location in the visual field. However, neurons within nearby columns responded only to bars of light at different orientations or locations. And this separation is found across multiple other modalities.
** There are many connections vertically within a column and comparatively fewer connections between columns.
** The neocortex looks largely identical everywhere. All the different ares contain the same types of neurons organized in the same way in all specied of mammals.
* Each neocortical column does exactly the same thing - the only difference is the type of input they receive and where they send their output. They seem to all implement some algorithm that is so general and universal that it can be applied to extremely diverse functions such as movement, language, and perception across every sensory modality
* The neocortex contains six layers of neurons connected in a complicated buy consistent way:
** In layer six, there are neurons that always project to the thalamus
** In layer five, a specific type of neuron always projects to the basal ganglia, the thalamus, and the motor areas.
** In layer four, there are neurons that always get input directly from the thalamus
* The properties of perception help us understand how the neocortex works:
** Filling in - the mind automatically and unconsciously fills in missing things.
** One at a time - the mind can see only one interpretation at a time
** Can't unsee - once it perceives an interpretation, the mind cannot unsee it. It likes to have an interpretation that explains sensory input
* Hermann von Helmholtz proposed that a person doesn't perceive what is experience; instead, he perceives what the brain thinks is there, through a process called inference.
* Brains must somehow recognize aspects of the world without being told the right answer. A suggestion for understanding this arises from Hinton's generative models, which have two modes:
** In recognition mode information flows up the network
** In generative mode, information flows backwards down the network.
** The network learns to recognize without supervision by generating its own data.
* Hallucinations, dreams, and imagination suggest that the brain is like a generative model:
** Cutting off sensory input to the neocortex makes it unstable. It gets stuck in a drifting generative process in which visual scenes are simulated without being constrained to actual sensory input
** Some neuroscientists refer to perception, even when it is functioning properly, as a "constrained hallucination".
** Only mammals and birds show unequivocal evidence of dreaming.
** The neocortex is always in an unstable balance between recognition and generation, and during our waking life, humans spend an unbalanced amount of time recognizing and comparatively less time generating. Perhaps dreams are a counterbalance to this, a way to stabilize the generative model through a process of forced generation. If we are deprived of sleep, the imbalance becomes so severe that the generative model in the neocortex becomes unstable and we start to hallucinate.
** It is natural for humans to imagine things that they are not currently experiencing and when you are imagining, this could simply be the neocortex in generation mode
** When people are imagining things, their pupils dilate as their brains stop processing actual visual data
** The same neocortical neurons activate during recognition and when you simply imagine the same thing. People with neocortical damage that impairs certain sensory data become equally impaired at simply imagining features of that same sensory data. Perception and imagination seem not to be separate systems but two sides of the same coin.
* The generative model in the neocortex seems to render a simulation of your environment so that it can predict things before they happen.
* Early mammals learned to predict everything, to monitor everything, and to experience surprise when things did not go as expected.
* If reflex circuits are reflex-prediction machines, and the critic in the basal ganglia is a reward prediction machine, then the neocortex is a world-prediction machine.
* The neocortex may be prewired to assume that incoming sensor data, whether visual, auditory, or somatosensory, represent 3D objects that exist separately from ourselves and can move on their own. It does not have to learn about space, time, and the difference between the self and others. Instead, it tries to explain all incoming sensory information it receives by assuming it must have been derived from a 3D world that unfolds over time.
* It is when the simulation in your neocortex becomes decoupled from the real external world around you - when it imagines things that are not there - that its power becomes most evident.

=== Imagination ===
* The neocortex brought three new abilities:
** Vicarious trial and error - Rats can play out each option in a maze before trying it. They do this only when decision are hard, when the costs are close to the benefits, or when the rules change. When the rat stopped at the decision point and turned its head back and forth, its hippocampus ceased to encode the actual location of the rat and instead went back and forth rapidly playing out the sequence of place codes that made up both possible future paths from the choice point. Once a rat has a world model of their environment, they can rapidly mentally explore it until they find a way to get around obstacles to get what they want.
** Counterfactual learnings - An experiment presenting rats with a continuous set of irreversible choices saw that the rats that turned back and reactivated the representation of a forgone choice also ended up changing their future choices. Counterfacgual leaning was a major enhancement in how ancestral brains solved the credit assignment problem. Causation may live more in psychology than in physics. It is constructed by our brains to enable us to learn vicariously from alternative past choices.
** Episodic memory - We don't truly remember episodic events. The process of episodic remembering is one of simulating an approximate re-creation of the past. When imagining future events, you are simulating a future reality; When remembering past events, you are simulating a past reality. Both are simulations. People's episodic memories are filled in during the remembering process.
*** The distinction between a made-up imagined scene and an actual episodic memory is thin in the neocortex - repeatedly imagining a past even that did not occur falsely increases a person's confidence that the event did occur.
*** In mammal brains, episodic memory emerges from a partnership between the older hippocampus and the newer neocortex. The hippocampus can quickly learn patterns, but cannot render a simulation of the world; the neocortex can simulate detailed aspects of the world, but cannot learn new patterns quickly. Episodic memory must be stored quickly, and thus the hippocampus, designed for the rapid pattern recognition of places, was repurposed to also aid in the rapid encoding of episodic memories. Distributed neural activations of sensory neocortex (ie simulations) can be retrieved by reactivating the corresponding pattern in the hippocampus. By retrieving and replaying recent memories alongside old memories, the hippocampus aids the neocortex in incorporating new memories without disrupting old ones.

=== Model-Based Reinforcement Learning ===
* Unlike TD-Gammon, AlphaZero was a model-based reinforcement learning algorithm. AlphaZero searched through possible future moves before deciding what to do next. It didn't simulate the trillions of possible futures; it prioritized and simulated only a thousand.
* The brilliance of simulation in mammal brains is likely to be the flexibility with which they employ different strategies and the intelligence with which they decide between them:
** Sometimes we pause to simulate our option, but sometimes we just act instinctively.
** Sometimes we pause to consider possible futures, but other times we pause to simulate some past event or alternative past choices.
** Sometimes we imagine rich details in our plans, playing out each individual detailed subtask, and sometimes we render just the general idea of the plan.
* A patient affected by a stroke in her prefrontal neocortex had lost all intention.
* In the back half of the neocortex is the sensory neocortex, where a simulation of the external world is rendered, but the frontal neocortex contains three main subregions:
** Motor cortex
** Granular prefrontal cortex (gPFC)
** Agranular cortex (aPFC)
* The frontal neocortex decides when and what to imagine.
* The primary input to the aPFC comes from the hippocampus, hypothalamus, and amygdala. The aPFC learns to model the animal itself, inferring the intent of behavior it observes, and uses this intent to predict what the animal will do next. The aPFC creates a model of an animal's goals.
* The columns of the aPFC might always be in one of three states:
** Silent (no intent)
** Recognize an intent and all predict the same next behavior
** Recognize and intent but predict different and inconsistent behaviors - the aPFC gets most excited when something goes wrong or something unexpected happens.
* The process might go something like:
** The degree of disagreement of predictions is a measure of uncertainty. It might be this that triggers simulations. If everything is going as expected, you can let the basal ganglia drive decisions without a model, but when uncertainty emerges (something nex, some contingency is broken, or costs are close to benefits), then simulation is triggered.
** The aPFC specifically explores the paths that it is already predicting an animal will take. It could be triggering the sensory neocortex to render a specific simulation of the world, or it could be that the basal ganglia determines the actions taken during these simulations.
** The basal ganglia accumulates votes for competing choices, with different populations of neurons representing each competing action ramping up excitement until it passes a choice threshold, at which point an action is selected. The aPFC is vicariously training the basal ganglia, which doesn't know whether the sensory neocortex is simulating the current world or an imaginary world, all it knows is that it is getting reinforced when it makes its choice.
* Habits are automated actions triggered by stimuli directly (they are model-free), and are controlled directly by the basal ganglia to save time and energy by avoiding unnecessary simulation and planning. Brains attempt to intelligently select when to model and when to rely on habit, but sometimes they make mistakes, and this is the origin of many of our irrational behaviors.
* Just as you don't perceive what you see, so intent is not real - it is a computational trick for making predictions about what an animal will do next.
* The basal ganglia has no intent or goal - it simply learns to repeat behaviors that have previously been reinforced.
* The aPFC, however, does have explicit goals. By simulating a future that terminates at some end result, it has an end state (a goal) that it seeks to achieve.
* The sensory cortex engages in passive inference - merely explaining and predicting sensory input. The aPFC engages in active inference - explaining one's own behavior and then using its predictions to actively change that behavior. It is repurposing the neocortical generative model for prediction to create volition.
* The basal ganglia begins as the teacher of the aPFC, but as a mammal develops, these roles flip, and the aPFC becomes the teacher of the basal ganglia. Perhaps this is part of a developmental program for constructing a model of self, starting by matching one's internal model to its observations, and then transitioning to pushing behavior to match one's internal model.
* Attention, working memory, executive control, and planning are all different applications of controlling the neocortical simulation.
** The aPFC's triggering of simulation is called imagination when it is unconstrained by current sensory input and attention when it is so constrained.
** Controlling ongoing behavior often also requires working memory - the maintenance of representations in the absence of any sensory cues while waiting. Working memory is just your aPFC trying to keep re-invoking an inner simulation until you no longer need it.
** The aPFC can inhibit the amygdala. This is the evolutionary beginning of behavioral inhibition, willpower, and self-control. In moments of willpower, you can inhibit your amygdala cravings, while in moments of weakness, the amygdala wins. But the aPFC is expensive to run and so when you are tired or stressed, it is less effective.
* The aPFC controls behavior not by showing, but by telling.

=== The Hierarchy of Goals, and Learning and Automation ===
* The motor cortex is a thin band of neocortex on the edge of the frontal cortex. It makes up a map of the entire body, dedicating lots of space to the parts of the body that animals have skilled motor control over (like the mouth and hands) and less to areas that they control less finely (like feet)
* This map is mirrored in the adjacent somatosensory cortex, the region of the neocortex that processes information coming from touch sensors in the skin and proprioceptive signals from muscles.
* The motor cortex is the primary system for controlling movement. It emerged tens of millions of years after the first mammals and only in the placental lineage.
* Perhaps it doesn't generate motor commands, but rather predictions. Perhaps it is in a constant state of observing body movements that occur in the nearby somatosensory cortex and then tries to explain the behavior and use these explanations to predict what the animal will do next. The motor cortex is wired to make its predictions come true.
* The aPFC learns to predict movements of navigational paths while the motor cortex learns to predict movements of specific body parts.
* This is "embodiment" - parts of the neocortex have an entire model of an animal's body that can be simulated, manipulated, and adjusted as time unfolds.
* The motor cortex was perhaps originally for motor planning. When learning a new movement the motor cortex simulations vicariously train the basal ganglia. Once a movement is well learned, the motor cortex is no longer needed.
* There is plenty of evidence that the premotor and motor cortices are activated both by doing movements and by imagining movements.
* Mental rehearsal of motor skills substantially increases performance across speaking, golf swings, and even surgical maneuvers.
** At the top of the hierarchy is the aPFC, where high-level goals are constructed based on amygdala and hypothalamus activation. It then propagates these goald to a nearby frontal region,
** The premotor cortex, which constructs subgoals and propagates these further until they reach
** The motor cortex, which then constructs subgoals
** The basal ganglia makes loops of connectivity with the frontal cortex, with the aPFC connecting to the front region of the basal ganglia (which then connects back to aPFC through the thalamus), and the motor cortex connecting to the back region of the basal ganglia (which then connects back to the motor cortex through a different region of the thalamus)
* So any level of goal, whether high-level or low-level, has both a self model in the frontal neocortex and a model-free system in the basal ganglia. The neocortex has a slower but more flexible system for training, and the basal ganglia offers a faster but less flexible version for well-trained paths and movements:
** The front part of the basal ganglia associates stimuli with high-level goals. It generates cravings.
** The aPFC, however, is what makes you pause and consider if you actually want to pursue these cravings
** The back part of the basal ganglia associates stimuli with low-level goals. It generates automatic skilled movements
** The motor cortex, however, makes you pause and plan out your exact movements ahead of time
* Learning a new behavior activates all levels of the motor hierarchy first, but as the behavior becomes automatic, it activates only lower levels of the hierarchy.
* The frontal neocortex is the locus of simulation, while the basal ganglia is the locus of automation.

== 15m ya - Primates and Metathinking ==

=== Theory of Mind: Group Living, Political Savvy, and Deception ===
* The ecology of Earth had found a beautiful equilibrium, with dinosaurs comfortably at the top of the food chain for well over 150m years, fish ruling the sea for even longer, and mammals and other animals finding their respective tiny but liveable niches.
* The Permian-Triassic extinction - An asteroid a few miles wide hits the Earth, killing over 70% of land-living vertebrates.
* Almost every dinosaur specied was extinct, except for the birds, and the following era is the Era of Mammals.
* The first primates lived in groups, and as they grew, they became relatively free from predation and food competition, and their brains exploded to well over a hundred time their original size.
* These early mammals uniquely gave birth to helpless children.
* Mammals engage in play much more than other vertebrates
* Group living led to unique social demands, and we find that the bigger the neocortex of a primate, the bigger its social group. This correlation does no hold for most other animals. Group living helps stave off predators.
* Animals in group living situations evolved tools to resolve disputes, leading to the development of mechanisms to signal strength and submission without having to actually engage in a physical altercation.
* Most lineages of mammals fell into one of four buckets of social systems: solitary, pair-bonded, harems, and multi-male groups.
* Groups also minimize competition through hierarchal rigidity. The strongest, biggest, and toughest become dominant.
* Something new was happening in sociality with these early mammals.
* There are processes of ever-escalating deceptions and counter-deceptions. Each individual is able to understand the other's intent, and that it is possible to manipulate the other's beliefs.
* Apes can tell the difference between "accidental" and "intentional", and between "unable" and "unwilling".
* Understanding the minds of others requires understanding not only their intentions but also their knowledge
* The act of inferring someone's intent and knowledge is called "theory of mind".
* Monkeys keep track of and remember each individual in their group and are able to recognize them by appearance and voice.
* They keep track not only of individuals, but also of the relationships between individuals, and are extremely sensitive to interactions that violate the social hierarchy
* It is not only physical power that determines one's social ranking, but also political power. One's evolutionary fitness improves with one's rank.
* Friendship and trust - monkeys most often rescue those whom they have previously formed grooming partnerships with. and they go out of their way to "make up" after aggressive interactions, especially those with nonfamily members.
* Early primates were frugivores, and had little competition for food from other species, and this may have opened the way to large brains and comples social groups because they had an abundance of callories and of time.
* Instead of building bigger muscles, they could build bigger brains to politic their way to the top. Monkey's social behavior shows an incredible degree of political forethought.
* Today's primates spend up to 20% of their day socializing, much more than most other mammals.
* They have many human social instincts, both good (friendships, reciprocity, reconciliation, trust, sharing) and bad (tribalism, nepotism, deception).

=== Modeling Our Own Minds and Other Minds ===
* From 70m ya, at half a grm to 10m ya at 350 grams, brains grew almost 1,000 times.
* New areas include two which are extremely interconnected with each other and have new input and output connectivities:
** The granular prefronal cortex (gPFC), which wraps around the much older agranular prefrontal cortex (aPFC)
** The primate sensory cortex (PSC)
* The gPFC becomes uniquely active during tasks that require self-reference, such as evaluating your own personality traits, general self-related mind wandering, considering your own feelings, thinking about your own intentions, and thinking about yourself in general. It seems to allow you to project yourself - your intentions, feelings, thoughts, personality, and knowledge - into your rendered simulations. Some people with damage to it no longer recognize themselves in a mirror.
* The older aPFC gets input directly from the amygdala and hippocampus, while the new primate gPFC receives most of its input directly from the aPFC. These new primate areas seem to be constructing a generative model of the older aPFC and sensory cortex itself. As the aPFC constructs explanations (intent) of amygdala and hippocampus activity, so perhaps the gPFC constructs explanations of the aPFC's model of intent - possibly inventing a "mind".
* There are levels of abstraction to explain our behavior:
** Reflexes say - I turn to the smell coming from the left because it is good
** Vertebrate structures say - Going left maximizes predicted future reward
** Mammalian structures say - Left leads to food
** Primate structures say - I'm hungry - ie, the gPFC constructs explanations of the simulation itself, of what the animal wants and knows and thinks - this is metacognition - the ability to think about thinking:
*** Reflexes drive valence responses
*** The vertebrate basal ganglia an amygdala can then learn new behaviors
*** The mammalian aPFC can then learn a generative model of this model-free behavior and construct explanation - this is a first-order model
*** The primate gPFC can then learn a more abstract generative model (a second-order model) of this aPFC-driven behavior and construct explanations of intent itself - making choices based on mind states and knowledge
* The gPFC also activates when inferring other people's intent and other people's knowledge and when recognizing false-beliefs
* People with gPFC damage are worse at recognizing and empathizing with other people's emotions, distinguishing jokes, and identifying faux pas.
* The bigger a primate's gPFC, the higher in the social hierarchy it tends to be. And in humans, the larger is his social network and his performance on theory of mind tasks.
* Our understanding of ourselves often gets cross-wired with our understanding of others, suggesting a common system for each
* Perhaps the gPFC builds a generative model of your own mind to use it to simulate the minds of others. Or perhaps the work of understanding the motivations of others helps us to construct the notion of a mind of our own.
* Theory of mind helps you to manage your reputation and hide your transgressions. It isn't about managing hungry predators or inaccessible prey, but rather about the subtler and far more cutting dangers of politics.

=== Simulation in Imitation, Teaching, and Anticipating the Future ===
* Primate tool use is more sophisticated than in other animals. Chimps exhibit over twenty different tool-using behaviors and actively manufacture their tools.
* The premotor and motor areas in a monkey activate when they perform specific fine motor skills but also when they watch others do them.
* Perhaps these "mirror neurons" are the mechanism by which primates engage in theory of mind - they imagine the action and then ask themselves "Why would I do this?" to deduce the other's intentions.
* People with impairments in performing specific movements also cannot understand the intentions of others doing those same movements.
* These mirror neurons help us learn new skills through observation.
* Without transmission from others, most chimps never figure tool use out on their own. The ability to use tools is less about ingenuity and more about transmissibility
* Acquiring an entirely novel motor skill by observation may have required, or at least hugely benefited from, entirely new machinery.
* Theory of mind enabled our ancestors to "actively teach", students can identify the intent of a complex skill and differentiate between the intentional and unintentional movements of experts, filtering out extraneous movements and extracting the essence of a skill.
* Theory of mind may have emerged for politicking and then been repurposed for imitation learning.
* The social-brain hypothesis is rivaled by the ecological-brain hypothesis - that it was the frugivore diet of early primates that drove the rapid expansion of their brains.
* Anticipating future needs may be another application of theory of mind - we can infer the intent of mind - our own or another's - in a different situation from our current one. People make similar types of mistakes in tasks of theory of mind and of anticipating future needs.

== 100k ya - Humans and Speech ==
=== Language for Sharing, Accumulating, and Complexifying Internal Simulations ===
* The "Great Ape Dictionary" - chronicles almost 100 sounds and gestures.
* No other animals use declarative labels or symbols - "That is a cow". Other animals may make a sound meaning "Predator", but this has an implied imperative "Run"
* Humans are the only animals with grammar. And all human languages have (a fundamentally similar) grammar. We are the only ones to have a natural tendency to construct and use language.
* Language lets us transfer our inner simulations to each other with an unprecedented degree of detail and accuracy. While concepts, ideas, thoughts, episodic memories and plans are not unique to humans, our ability to deliberately transfer them is only possible due to language
* Language expands the scope of sources a brain can extract learnings from:
** Vertebrates (reinforcing) - Own actual actions (trial and error)
** Mammals (simulating) - Imagined actions (vicarious trial and error)
** Primates (mentalizing) - Others' actual actions (imitation learning)
** Humans (speaking) - Others' imagined actions
* We share the outcomes of our own inner vicarious trial and errors so that the whole group can learn from our imaginations.
* We can form common myths and have entirely made-up entities and stories persist merely because they hop between our brains. Common myths of things like countries, money, corporations, and governments allow us to cooperate with billions of strangers.
* The power of language is not its products but the process of ideas being transferred, accumulated, and modified across generations.
* Human children are "over-imitators", performing all steps they see, including irrelevant ones.
* Without language, the inner simulations of chimpanzees and other animals do not accumulate, and thus inventions that are above a certain threshold of complexity - the best ones - are forever out of their reach.
* The corpus of ideas accumulated reached a tipping point when the total sum no longer fits into the brain of a single human:
** First we got bigger brains
** Then we became more specialized in our groups
** Then population size expanded
** Then we invented writing - now we accumulate our shared simulations across generations. We are the hive brain apes.
* Language transformed the human brain from an ephemeral organ to an eternal medium of accumulating inventions.
* Our ascent over the last few thousand years had nothing to do with better genes and everything to do with the accumulation of better and more sophisticated ideas.

=== Language in the Brain ===
* Broca's area supports the production of speech and writing.
* Wernicke's area supports the understanding of speech and reading.
* The human neocortex has unique control of the vocal cords, surely an adaptation for using verbal language.
* Language emerges from specific regions in the brain and is contained in a subnetwork almost always found on the left side of the neocortex.
* Language is a specific and independent skill that evolution wove into our brains.
* In other primates, these language areas are present in the neocortex, but have nothing to do with communication.
* Emotional expression emerge from a system entirely separate from language:
** Other primates have only a single emotional-expression system located in the amygdala and brainstem. Human laughs, cries, and scowls are evolutionary remnants of the system from which ape hoots and gestures emerge.
** We have a second separate system, supporting voluntary control of facial muscles that is controlled by the neocortex.
* The newer language system needs to be taught - if a child goes long enough without being taught language, he or she will be unable to acquire it later in life. Unlike innate emotional expressions, features of language differ greatly across cultures. And indeed a human baby born without any neocortex will still express these emotions in the usual way but will never speak.
* A hardwired tendency toward gestural and vocal turn-taking seems to be the platform on which language is built.
* By nine months, babies show joint attention to objects. In contrast, chimps show no interest in ensuring someone else attends to the same object they do. The more joint attention expressed by an infant at the age of one year, the larger will be her vocabulary 12 months later.
* Humans may have evolved a unique hardwired instinct to ask questions to inquire about the inner simulations of others. It isn't Broca's or Wernicke's areas that are new, but rather the underlying learning program that repurposed them for language. There is not a single region but rather a curriculum that forces a complex network of regions to work together.

=== The Perfect Storm ===
* Around 2.5m ya something mysterious happened with the human brain rapidly becoming over three times larger.
* There are various adaptations:
** There is a shift to eating meat (up to 85% meat diet!) and to making tools to cut it.
** They're walking upright.
** Their shoulders and torsos become adapted for throwing.
** Their legs and feet adapt for endurance running
** While other mammals pant to lower their body temperature, humans sweat
** Their mouths and guts shrank and they invent cooking with less digestion. Every human culture uses cooking
** They have controlled use of fire
** Big brains are hard to fit through birth canals and the human solution is premature birthing - babies are not born when they are ready to be born, but when their brains hit the max size to fit through the birth canal. It takes a human brain 12 years before it has reached its full adult size.
** As a result the parenting style changed, leading to longer-term pairings.
** "Grandmothering - only humans and orcas have females that are not reproductively capable until death. Maybe the menopause evolved to push grandmothers to shift their focus to supporting their children's children.
** The larynx and vocal cords of our ancestors were not adapted to vocal language until about 500k ya, and there is substantial evidence that language existed at least 100k ya. Our common ancestor from 100k ya almost definitely spoke a language of a complexity equal to ours.
* Most altruistic behaviors are the result of kin selection, and the essential feature for reciprocal altruism to successfully propagate throughout a group is the detection and punishment of defectors.
* Humans are, relative to other animals, both by far the most altruistic to unrelated strangers and the most cruel - no other animal commits genocide.
* Homo Erectus probably had the ability to assign declarative labels and perhaps even use some simplified grammars*
* Language my have emerged as a trick between parents and children, since the most prominent learning program for language is the interplay of joint attention and proto-conversations between parents and children.
* As much as 70% of human conversation is gossip:
** Gossip enables a stable system of reciprocal altruism by sharing information about betrayals and about heroic acts.
** The more severe the costs of cheating, the more altruistic it was optimal to behave.
** For every incremental increase in gossip and punishment of violators, the more altruistic it was optimal to be.
* As social groups got bigger and more ideas accumulated across generations, humans became better hunters and cooks and brains got bigger and births got earlier.
* By 100k ya, there were at least four species of humans spread out across the planet:
** Homo floresiensis was in Indonesia
** Homo erectus was in Asia
** Homo neanderthalensis was in colder Europe
** Homo sapiens had remained in Africa
* By 40k ya, only Homo sapiens remained.

=== ChatGPT ===
* Both LLMs and the neocortical areas for language seem to be engaging in prediction, generalizing past experiences and applying them to new sentences, and guessing what comes next, though more is happening in your brain than merely the automatic prediction of words.
* The foundation of language learning is not sequence learning but the tethering of symbols to components of a child's already present inner simulation.
* The neocortex evolved long before words, already wired to render a simulated world that captures an incredibly vast and accurate set of physical rules and attributes of the actual world.
* The human brain contains both a language prediction system and an inner simulation.
* The intertwining of mentalizing and language is ubiquitous. Wernicke's area is right in the middle of the primate mentalizing regions.
* We are capable of puppeteering other minds because language is, it seems, built right on top of a direct window to our inner simulation. Hearing sentences directly and automatically triggers specific mental imagery. This is why if someone is saying something that upsets us, we cannot simply "not listen"; we must cover our ears, otherwise the words directly trigger simulations whether we like it or not.
* By predicting not just the answer but also the next step in reasoning about the answer, an LLM begins to exhibit emergent properties of thinking.
* In the human brain, language is the window to our inner simulation. Language is the interface to our mental world.
* If there is anything that truly makes humans unique, it is that the mind is no longer singular but is tethered to others through a long history of accumulated ideas.

[[Category:Consciousness]]
[[Category:Books]]

The Song of the Cell

2025-04-21T15:54:19Z

Rob: /* The Songs of the Cell */

Every cell in a multicellular organism is surrounded by an oily membrane that separates it from other cells and from the extracellular fluid that bathes all cells. The cell surface membrane is permeable to certain substances, thereby allowing an exchange of nutrients and gases to take place between the interior of the cell and the fluid surrounding it. Inside the cell is the nucleus, which has a membrane of its own and is surrounded by an intracellular fluid called the cytoplasm. The nucleus contains the chromosomes, long thin structures made of DNA that carry genes like beads on a string. In addition to controlling the cell's ability to reproduce itself, genes tell the cell what proteins to make to carry out its activities. The actual machinery for making proteins is located in the cytoplasm. Seen from this shared perspective, the cell is the fundamental unit of life, the structural and functional basis of all tissues and organs in all animals and plants.

Besides their common biological features, all cells have specialized functions:
* Liver cells, for instance, carry out digestive activities
* Brain cells have particular ways of processing information and communicating with one another. These interactions allow nerve cells in the brains to form complete circuits that carry and transform information

From The Song of the Cell by Mukherjee

== Introduction ==

* To be living, an organism must have the capacity to:
** to reproduce
** to grow
** to metabolize
** to adapt to stimuli
** to maintain its internal miliau
* Complex multicellular living beings also possess emergent properties, which emerge from systems of cells:
** to defend against injury or invasion
** organs with specialized functions,
** physiologic systems of communication between organs
** even sentience and cognition
* It is difficult to imagine life without cells, or to imagine cells without life

* A cell is an autonomous living unit that acts as a decoding machine for a gene. Genes provide instructions to build proteins, the molecules that perform virtually all the work in a cell. Proteins enable biological reactions, coordinate signals within the cell, form its structural elements, and turn genes on and off to regulate a cell's identity, metabolism, growth, and death. They are the central functionaries in biology, the molecular machines that enable life.
* A cell thus transforms information into form, genetic code into proteins. A gene without a cell is lifeless. A cell brings materiality and physicality to a set of genes. But not only that.
* Having unpacked the code by synthesizing a select set of proteins that is encoded in its genes, a cell becomes an integrating machine. It uses this set of proteins (and the biochemical products made by proteins) in conjunction with one another to start coordinating its function, its behavior (movement, metabolism, signaling, delivering nutrients to other cells, surveying for foreign objects) to achieve the properties of life. And that behavior, in turn, manifests as the behavior of the organism. The metabolism of the organism reposes in the metabolism of the cell, And the same for the reproduction, repair, survival, and death of the organism
* Finally, the cell is a dividing machine. Molecules within the cell - proteins again - initiate the process of duplicating the genome. The internal organization of the cell changes. Chromosomes, where the genetic material of a cell is physically located, divide, and this division drives growth, repair, regeneration, and ultimately, reproduction, among the fundamental, defining features of life.

== The Universal Cell ==

* You have to think of a cell as a functional site for all physiological chemical reactions, as an organizing unit for all tissues, and as the unifying locus for physiology and pathology.
* You have to move from a continuous organization of the biological world to a description that involves discontinuous, discrete, autonomous elements that unify the world:
** See past flesh (continuous, corporeal, visible)
** To blood (invisible, corpuscular, discontinuous)

* Raspail - "A cell is a kind of laboratory" - it enables physiology
* Virchow - "The body is a cell state in which every cell is a citizen."

Tenets of cell theory:
* All living organisms are composed of one or more cells
* The cell is the basic unit of structure and organization in organisms
* All cells come from other cells
* Normal physiology is the function of cellular physiology
* Disease, the disruption of physiology, is the result of the disrupted physiology of the cell

== The Pathogenic Cell ==

* Germ theory - microbes are independent, living cells capable, in some cases, of causing human illnesses
* Bacterial cells, Pasteur concluded, are carried in air and dust. Putrefaction or rotting was not caused by the inner decomposition of living creatures - or some visceral form of interior sin. Rather decomposition only happened when these bacterial cells landed on the broth.
* Infections were invasions by microbes - single-celled organisms that entered other organisms and caused pathological changes and tissue degeneration

* Antibiotics recognize some molecular component of hyman cells that is different from a bacterial cell. They are cellular medicines, drugs that rely on the distinctions between a microbial cell and a human cell.

Every cell on earth belongs to one of three branches:
* Bacteria - single-celled organisms that are surrounded by a cell membrane, lack particular cellular structure found in animal and plant cells and possess other structure that are unique to them.
** They are ferociously successfully and dominate the cellular world. Not just pathogens - our skin, guts, mouths are teeming with several billion bacteria that cause not disease whatsoever. Humans are just "nice-looking luggage to carry bacteria around the world".
** They live in the hottest and coldest parts of the world. They are autonomous, mobile, communicative, and reproductive
* Eukaryotes - cells containing a nucleus, which is a storage site for chromosomes (bacteria are prokaryotes - before nuclei).
** We and other eukaryotes are feeble, finicky beings capable of living in vastly more limited environments and restricted ecological niches
* Archaea - They look like bacteria, are tiny and lack some of the structures associated with animal and plant cells. Recently established as a separate domain, we know relatively little about them

The history of the cell:
* The first cells arose on Earth some 3.5-4bn yeats ago, about 700m years are the birth of the Earth.
* The simplest cell (a protocell) had to possess a generic information system that could reproduce itself. This was probably made of RNA.
* Two RNA molecules were probably needed - a template and a duplicator - and they had to avoid separation, so some sort of structure - a spherical membrane, was likely needed to confine them. These three components may have been the first cell
* At first the RNA would duplicate within the confines of the sphere, but at some point it would grow too big and split in two.
* Then evolution would select more and more complex features of the cell, eventually replacing RNA with DNA as the information carrier.
* Bacteria evolved out of that simple progenitor about 3bn years ago and they continue to evolve today. Archaea are probably at least as old as bacteria
* About 2bn years ago, evolution took a strange and inexplicable turn, when a cell that is the common ancestor of human cells, plant cells, fungi cells, animal cells, and amoebal cells appeared on Earth.
* This ancestor was recognizably a "modern" cell, with an exquisite internal structure and unprecedented molecular dynamism, all driven by sophisticated nanomachines encoded by thousands of new genes that are largely unknown in bacteria.
* New evidence suggests that this "modern" eukaryotic cell arose within archaea, so that we are a relatively recent sub-branch of archaea.

== The Organized Cell ==

The membrane:
* Has two layers of lipids
* Proteins are embedded in the membrane, like hatches or channels

The protoplasm/cytoplasm:
* is a mind-bogglingly complex soup of chemical
* It has a molecular "skeleton" that maintains the form of the cell and is called the cytoskeleton. It is made of actin and tubulin which form tubular structures and tethers components of the cell together.

The ribosome:
* Is a massive macromolecular structure, a multipart assemblage.
* It captures RNAs and decodes their instructions to synthesize proteins

Proteins:
* Are the workhorses of the cell.
* they create structural components, are receptors for signals from outside, form pores and channels across the membrane, and are the regulators that switch genes on and off in response to stimuli.
* Building proteins is one of the cell's main tasks.

Organelles:
* Are mini organs found inside cells

The mitochondria:
* Are organelles that are the cells fuel generators - maybe originally microbrial cells that developed the capacity to produce energy via a chemical reaction involving oxygen and glucose, and which were engulfed or captured by other cells:
* They are found in all cells, but are particularly dense in muscle cells, fat cells, certain brain cells, and other cells that need the most energy or regulate energy storage.
* They are wrapped around the tails of sperm to provide swimming energy. They have no autonomous life and can live only within cells.
* They produce energy through an aerobic reaction, breaking down sugar and feeding the result into a cycle of reactions to make ATP (adenosine triphosphate), which is the central currency of energy in virtually all living cells. There is a faster, but less efficient anaerobic production of ATP, which happens directly in the protoplasm.

The endoplasmic reticulum (ER):
* Is an organelle that is a maze of winding, tortuous pathways.
* Acts as a postal system. RNA is translated into a protein by the ribosome and then pushed into the ER, which sends it to the Golgi apparatus, which routes it to its final destination in the cell

The nucleus:
* Is an organelle that is found in all plant and animal cells (but not in bacteria)
* Is the storage bank for DNA, for the genome
* Proteins enter through the pores of the nuclear membrane and bind to the DNA and turn genes on and off.
* The set of on/off genes instructs a neuron to be a neuron and a white cell to be a white cell.
* During the development of an organism, genes - or rather proteins encoded by genes - tell cells about their relative positions and command their future fates.
* Genes are turned on and off by external stimuli such as hormones, which also signal changes in a cell's behavior.

Claude Bernard in the 1870 shifted physiology's focus from action to the maintenance of fixity. A major point of physiological activity, paradoxically, was to enable stasis. Don't just do something, stand there! - homeostasis.

== The Dividing Cell ==

* Every cell is the product of birth from another cell
* Not every cell is capable of reproducing - some cells, such as neurons, have undergone permanent division and will never divide again
* Mitosis (from the Greek for thread) is the process of dividing to produce new cells to build organs and tissues
* Meiosis (from the Greek for lessening) is the birth of new cells, sperm, and eggs for the purpose of reproduction - to make a new organism

The lifecycle for a multicellular organism is a back and forth between meiosis and mitosis:
* Humans start with 46 chromosomes in every bodily cell and produce sperm cells in the testes and egg cells in the ovaries via meiosis, each ending up with 23 chromosomes
* When sperm and egg meet to form a zygote, the number of chromosomes is restored to 46
* The zygote grows through cell division, mitosis, to produce the embryo, and then develops progressively mature tissues and organs - heart, lungs, blood, kidneys, brain - with cells that have 46 chromosomes each
* As the organism matures, it eventually develops a gonad (testes or ovaries), with 46 chromosomes in each cell
* When the cells in the gonads make male and female reproductive cells, they undergo meiosis, generating sperm and eggs with 23 chromosomes each
* Fertilization restores the number to 46. A zygote is born and the cycle repeats. Meiosis, mitosis, meiosis. Halve, restore, grow. Halve, restore, grow.

The division of cells goes in phases:
* G0 - The resting cycle, quiescent. Some cells will never divide, they are post-mitotic. Most mature neurons are good examples
* G1 - The cell decides to divide and prepares for division.
* S - From synthesis of duplicate chromosomes. The chromosomes are duplicated
* G2 - A second resting phase, a final checkpoint before division, where the cells checks the fidelity of its DNA replication. A cell showered with DNA-damaging radiation or chemotherapy might halt at this stage. Proteins called the Guardians of the Genome, including the p53 tumor suppressor, scan the genome and the cell to ensure its health before generating new cells
* M - for mitosis. The nuclear membrane dissolves, the molecular apparatus to pull apart the duplicated chromosomes is fully assembled, they are separated and the cytoplasm of the cell is halved. The mother cell generates two daughter cells.

== The Tampered Cell ==

* In Down syndrom an extra chromosome - number 21 - is left over in the egg or sperm cell.
* Gene editing - making directed, deliberate, and specific changes in a genome - is most commonly done using a bacterial protein called Cas9, which is introduced into human cells and then "guided" to a specific part of a cell's genome to make a deliberate alteration: typically a cut that usually disables the targeted gene. Bacteria use this system to chop up the genes of invading viruses, thereby inactivating the invader.
* Cas9, when combined with a piece of RNA to guide it, can be directed to make a deliberate change in the human genome. It's like finding and erasing one word in one sentence on one page in one volume in an 80k book library. Recently, it has been modified to implement a vast array of potential changes in a gene, such as adding new information or making more subtle alteration.

* Multicellularity is ancient. It evolved independently, and in multiple different species many, many times. Collective existence - above isolation - was so selectively advantageous that the forces of natural selection gravitated repeatedly toward the collective.
* Specialization and cooperativity conserve energy and resources allowing new, synergistic functions to develop. One part of the collective can handle waste disposal, for example, while another acquires food. Multicellularity may have evolved to support larger sizes and rapid movement, allowing the organism to escape predation or to make faster coordinated movements toward weak gradients of food.

== The Developing Cell ==

* The zygote, floating in the womb, divides into two, then four, and so on until a small ball of cells is formed
* Cells keep dividing and moving until the mass starts to hollow out within and become a blastocyst. The outer wall will attach to the maternal womb and become part of the placenta, the membranes around the fetus, and the umbilical cord. The inner wall will develop into the human fetus.
* The inner cells mass starts to form two layers of cells, the outer ectoderm and the inner endoderm, and after three weeks a third layer lodges between them, the mesoderm. This three-layered embryo is the basis of every organ in the human body:
** The ectoderm will become the outer surface - skin, hair, nails, teeth, the lens of the eye
** The endoderm becomes the inner surface - the intestines and the lungs
** The mesoderm handles everything inbetween - muscle, bone, blood, heart.
* Within the mesoderm, a series of cells assemble along a thin axis to form a rodlike structure called the notochord, which spans from the front of the embryo to its back. This becomes the GPS of the embryo, determining the position and axis of the internal organs as well as secreting proteins called inducers. Just above the notochord, a section of the ectoderm invaginates, folding inward and forming a tube, which will become the precursor of the nervous system - the brain, spinal cord, and nerves. It loses its function during childhood and its only remnant in the adult body is the pulp stuck between the skeletal bones - the notochord is trapped inside the bony prison of the very creature it has created.
* Once the notochord and the neural tube have been generated, individual organs begin to form out of the three layers - the primitive heart, the liver bud, the intestines, the kidneys.
* Three weeks after gestation, the heart will generate its first beat. A week later, one part of the neural tube will begin to protrude out into the beginnings of the human brain.
* The growth of an embryo is a process, a cascade. At each stage, preexisting cells release proteins and chemicals that tell the newly emerging and newly migrating cells where to go and what to become. They command the formation of other layers and, later, the formation of tissues and organs. And the cells within these layers themselves turn genes on and off, in response to location and their intrinsic properties, to obtain their self-identities. One stage builds upon signals emerging from a prior stage - the tumble of epigenesis that early embryologists had captured so vividly.

* Thalidomide - a sedative medecine developed in the 1950s, caused sever congenital malformations - some babies were born with severely shortened or absent limbs. It bound to one or several of the proteins in the cells that directed the development of the embryo thus altering or destroying the instructions.

== The Restless Cell (Red Blood Cells) ==

* Red cells, while cells, platelets
* Normal white cells have two main forms: lymphocytes and leukocytes
* Leukemia is a cancer of white blood cells.
* Blood is the central mechanism of long-distance communication in humans. It transmits hormones, nutrients, oxygen, and waste products. It connects to and talks to every organ and allows communication between one organ and others.
* 90% of the wight of a red cell is hemoglobin, which carries oxygen (bound in iron). Its main purpose is to ferry oxygen to tissues in all the body's organs.
* In addition to cells, plasma, the fluid component of blood, carries other materials crucial to human physiology: carbon dioxide, hormones, metabolites, waste products, nutrients, clotting factors, and chemical signals
* Blood groups were worked out in the 1930s:
** A - Can accept from other As or from Os
** B - Can accept from other Bs or from Os
** O - Universal Donors. Can donate to anyone but can only accept from other Os
** AB - Universal Acceptors. Can accept from anyone but can only donate to other ABs

== The Healing Cell (Platelets) ==

* 1912 - Coining of the term "heart attack" for when the artery bringing blood to the heart is blocked by a clot
* 1897 - invention of aspirin. In the 1960s, we learned that it blocks an enzyme that produces injury-sensing chemicals, and therefore decreases platelet activation and subsequent clots.

== The Guardian Cell (White Blood Cells) ==

* White blood cells do not contain hemoglobin, have nuclei, and are irregularly shaped
* Inflammation and immune response - the recruitment of immune cells to the site of injury, and their activation once they have detected a foreign substance.
* The immune cells move toward the site of inflammation autonomously (attracted by chemokine and cytokine proteins released by the injured cells)
* Once there, they try to eat the infectious agent or irritant - phagocytosis - the engulfment and consumption of an infectious agent by the immune cell
* Multicellular organisms have been at war with microbes throughout evolutionary history to such an extant that we have defined each other. Our first-responder immune cells carry pattern-recognition receptors that are inherently designed to latch on to molecules found in microbial cells or injured cells that are not specific to a particular pathogen, but are broadly present in all bacteria and viruses. They sniff around the body looking for patterns of injury and infection - substances that signal invasion and pathogenicity.
* The "innate immune system" is the oldest part of the immune system, and some form of it is found in virtually all multicellular creatures.
* We associate immunity with B and T cells or with antibodies, but without neutrophils and macrophages, we would meet the fate of the decomposing fly.

* As early as AD 900, medical healers in China had realized that people who survived small pox did not catch the illness again, thus making them ideal caregivers for those suffering from the disease. It is as if the body retained a "memory" of the initial exposure.
* Chinese doctors started to vaccinate children by harvesting some pox, grinding it up and blowing it in the child's nose. The dose had to be right - if too much then the child would simply catch the disease.
* By the 1700s, the practice had spread throughout the Arab word and became known as "buying the pox".
* In 1775, the term "immunity" is coined.
* The term "vaccine" comes from cowpox, with vacca being latin for cow.

== The Defending Cell (B Cells) ==

* The terms "antitoxin" and "antibody" coined in 1890s. An antibody was a body - a protein - that locked on to another substance. And an antigen was a substance that generated an antibody.
* Our bodies produce B cells primarily in the bone marrow, which then mature in the lymph nodes.
* If the structure of antibodies was malleable then the genes that encoded them must also be malleable - by mutation.
* In cell biology and genetics - in fact in most of the biological world - learning and memory typically happen by mutation, not instruction or aspiration.
* When the connection is made, and a particular lymphocyte with a particular receptor is brought into the presence of the particular antigen, one of the greatest small spectacles in nature occurs. The cell enlarges, begins making new DNA at a great rate and turns into what is termed, appropriately, a blast. It then begins dividing, replicating itself into a new colony of identical cells all labeled with the same receptor. In the end, the dominant B cell clones, displaying the "right" receptor (the one that best binds the antigen) blast away, outgrowing all others. It is a Darwinian process, much like the finch with the right beak is "chosen" by natural selection.
* These blasts now begin to secrete the receptor into the blood. Freed from the B cell's membrane and now floating in the blood, the receptor "becomes" the antibody. And when the antibody is bound to its target, it can summon a cascade of proteins to poison the microbe and can recruit macrophage to devour, or phagocytose, it. Decades later, researchers demonstrated that some of the activated B cells don't simply peter out. They persist in the body in the form of memory cells. The new cluster of cells stimulated by the antigen is a memory, no less. Once the fulminant infection has ceased and the microbe cleared, some of these B cells become more quiescent, but they persist - finches huddled in the cave. When the body encounters the antigen again, the memory B cell is reactivated. It arises out of dormancy into active division to mature into an antibody-making plasma cell, thereby encoding an immunological memory. The locus of immunological memory, in summary, is not a protein that persists. It is a B cell, previously stimulated, that bears the memory of the prior exposure.
* Ultimately the B cell matures into a cell so single-mindedly dedicated to antibody production that its structure and metabolism are altered to facilitate the process. It is now a cell dedicated to making antibodies - a plasma cell. Some of these plasma cells also become long lived and retain the memory of the infection.

== The Discerning Cell (T Cells) ==

* The thymus is a gland that sits above the heart.
* What do T cells do during an infection? There are tow pathological worlds of microbes, an outer world of a bacterium or a virus floating outside the cell, in lymph fluid or blood, or in tissues, and an inner world of a virus that is embedded and living within a cell.
* This is what viruses do. They go native and because antibodies cannot enter cells, we need a cell that can discriminate the self from the nonself.
* T cells can't get inside cells.
* The job of the helper T cell is to bridge the innate and adaptive immune system - macrophages and monocytes on one end, and B and T cells on the other.
* Unlike an antibody, a gunslinging sheriff itching for a showdown with a gang of molecular criminals in the center of town, a T cell is the gumshoe detective going door to door to look for perpetrators hiding inside.
* In the immune system there is a recognition system that needs no cellular context (B cells and antibodies), while the other is triggered only when the foreign protein is presented in the context of a cell (T cells). So viruses and bacteria are not just cleared from the blood by antibodies but are also cleared from infected cells where they could otherwise be harbored safely, by T cells.

* On June 5, 1981, AIDS was first recorded in a CDC report. It was named in July 1982. It attacks cellular immunity, killing the very system designed to kill it. The virus is called Human Immunodeficiency Virus (HIV).
* The CD4-positive T cellls is the central bridge between innate immunity and adaptive immunity.

== The Tolerant Cell (T Cells II) ==

* Every cell in your body expresses a set of histocompatibility (H2) proteins that are different from the proteins expressed by a stranger's cells.
* Graft rejection (likely important for primitive organisms) and invader recognition (important for complex, multicellular organisms) are thus combined into a single system. Both functions repose in the T cell's capacity to recognize the MHC peptide complex, or the altered self.
* The self is defined, in part, by what is forbidden to attack it. Biologically speaking, the self is demarcated not by what is asserted but by what is invisible: it is what the immune system cannot see.
* T cells are born in the bone marrow as immature cells and migrate to the thymus to mature.
* T cell deletion in the thymus - a mechanism called central tolerance because it affects all T cells during their central maturation - isn't enough to guarantee that immune cells don't end up attacking the self. There is a further phenomenon called peripheral tolerance; here tolerance is induced once the T cells have left the thymus
* The Tcell, which confers active immunity and incites inflammation, and the regulatory T cell, which dampens these processes arise from the same parent cells: T cell precursors in the bone marrow. Immunity and its opposite are twinned: the Cain of inflammation conjoined with the Abel of tolerance.
* There are multiple safety switches to prevent T cells attacking normal cells.

* Cancers are invisible to the immune system. Cancer is a distorted version of our normal selves. To attack a cancer, one has to make it re-visible to the immune system and that system must find some determinant in the cancer that can enable an attack, without concomitantly destroying the normal cell.

* Blood. A cosmos of cells:
** The restless ones: red blood cells.
** The guardians: multilobed neutrophils that mount the first phases of the immune response.
** The healers: tiny platelets - once dismissed as fragmentary nonsense - that redefined how we respond to breaches in the body.
** The defenders, the discerners: B cells that make antibody missiles, T cells, door-to-door wanderers that can detect even the whiff of an invader, including possibly, cancer.
* It is a conglomerate of organs, a system of systems.
* It has built training camps for its armies (lymph nodes), highways and alleys to move its cells (blood vessels).
* It has citadels and walls that are constantly being surveyed and repaired by its residents (neutrophils and platelets).
* It has invented a system of identification cards to recognize its citizens and eject intruders (T cells) and an army to guard itself from invaders (B cells).
* It has evolved language, organization, memory, architecture, subcultures, and self-recognition. Perhaps we might think of it as a cellular civilization

== The Pandemic ==

* The gene TLR7 (Toll-Like Receptor 7) is one of the key detectors of viral invasion.
* The virus was most deadly when it infected a host whose early antiviral response had been functionally paralyzed - like a raider that had come into an unlocked house. The pathogenicity of SARS_COV2 perhaps lay precisely in its ability to dupr cells into believing that it is not pathogenic.
If you mount a robust innate immune response during the early phase of infection, you control the virus and have a mild disease. If you don't, you have uncontrolled virus replication in the lung that fuels the fire of inflammation leading to severe disease.

* Cellular specialization and citizenship - the hallmark of the cell biology of an organ - result in the profound "emergent" properties of human physiology - ie properties that can only emerge when multiple cells coordinate their functions and work together. A heartbeat. A thought. And the restoration of constancy - the orchestration of homeostasis.

== The Citizen Cell (Heart) ==

* The heart will beat more than 2bn times over an average person's life.
* The heart is two pumps:
** The right-sided pump (veins to heart to lung) collects blood from the veins of the body. Exhausted and depleted, having delivered oxygen and nutrients to the organs, "venous" blood (often darker red than bright crimson) pours into the upper right chamber called the right atrium. It then passes through a valve and is moved into the pumping chamber, the right ventricle. A powerful heave from the right ventricle pumps the blood to the lungs.
** The lungs, having received blood from the right side of the heart, oxygenate the blood and clear the carbon dioxide. Replete with oxygen and cleansed, blood, nos a vivid crimson, moves to the left side. It collects in the left atrium of the heart. It si then pushed into the left ventricle. It is this left ventricle, perhaps the most tireless muscle in the body, that ejects te blood forcefully into the wide arc of the aorta, the major blood vessel that carries oxygenated blood to the body, and to the brain.

* There are two systems of interconnected fibers inside a muscle cell: actin and myosin
* Each muscle cell has thousand of ropes - bands of actin in parallel with bands of myosin. As the ropes, lines side by side, slide against each other - clutch, pull, release - the edges of the cell are also yanked, and the cell is dragged into a contraction. The process requires energy, of course, and every heart cell and muscle cell is chock-full of mitochondria to supply the energy required for the two fibers to slide.
* There are three fundamental types of muscle cells:
** cardiac muscle
** skeletal muscle (that moves your arms on command)
** smooth muscle (that moves involuntarily, but consistently, allowing say liquid in the intestines to keep moving
* Heart cells are connected to each other through minuscule molecular channels, called gap junctions. Every cell is inherently designed to communicate with the rest. Although many, they behave as one. When a stimulus to contract is generated in one cell, it automatically travels to the next cell, resulting in its stimulation, and ultimately resulting in contraction in unison.

== The Contemplating Cell (Neuron) ==

* Neurons possess a cell body - the some - from which sprout dozens, hundreds, or even thousands of branch-like projections called dendrites. And they possess an outflow tract - an "axon" - that extends to the next cell, which is separated from the second neuron by an intervening speace - the synapse. The nervous system is wired, but the wires consist of cells connected to cells connected to cells with intervening spaces between them.
* Information travels unidirectionally. The dendrites receive the impulse, which is then moved through the cell body, out through the axon, through the synapse to the next nerve cell
* Nerve cells chatter with each other - collecting inputs via dendrites and generating outputs via the axon, and this intercellular chatter gives rise to the profound properties of the nervous system: sentience, sensation, consciousness, memory, thinking, and feeling.
* Chemical transmitters are stored in vesicles (membrane-bound sacs) at the end of the axon.
* The synapse can not just excite the neuron to fire, but can also be an inhibitory synapse, making the next neuron less prone to excitation. A single neuron can thus have positive inputs and negative inputs from other neurons. Its job is to integrate these inputs and his integrated total of excitatory and inhibitory inputs determines whether a neuron will fire or not.

* Glial cells are present all over the nervous system - in about the same number as neurons. They don't generate electrical impulse but they are extraordinarily diverse in structure and function.
* Synaptic pruning is thought to involve the paring back of structures, eliminating the synaptic connection at that site - akin to removing, or cutting the soldering joint between two wires. Our brains make connections in vast excess, and then we pare back the excess
* The secret of learning is the systematic elimination of excess. We grow mostly by dying. We are hardwired not to be hardwired, and this anatomical plasticity may be the key to the plasticity in our minds.
* Specialized cells known as microglia - spidery and many-fingered - had been seen crawling around the brain, scrounging for debris, and their role in eliminating pathogens and cellular waster had been known for decades. But they are also found coiled around synapses that have been marked for elimination. They nibble at the synaptic connections between neurons and pare them away. They are the brain's constant gardeners.
* Microgiglia use proteins and processes to mark synapses to be nibbled and ingest the bits of a neuron involved in the synaptic connections. The very proteins and pathways that are used to clear pathogens in the body have been repurposed to fine-tune connections between neurons. Microglia have evolved to "eat " pieces of our own brain.
* Synapses compete against each other and the strongest synapse wins.
* Dysfunctions in glial pruning may be related to schizophrenia - a disease where pruning doesn't occur appropriately. Maybe also Alzheimers, multiple sclerosis, and autism.

* An electrical impulse arrives at the end of the neuron - the axon terminal - and causes the release of chemical neurotransmitters into the synapse. These chemicals, in turn, open channels in the next neuron, and ions surge in, reinitiating the impulse. This is the fast electrical brain.
* But the chemical signals also create a cascade of slow signals in the neuron. Neuronal signaling instigates profound biochemical and metabolic changes in the recipient cell causing alterations in metabolism, in gene expression, and in the nature and concentration of chemical transmitters that are secreted into the synapse. And these slow changes in turn alter the electrical conduction of an impulse from nerve to nerve.
* We might divide the pathologies of the brain into those that affect the fast electrical signals, those that impact the slow biochemical cascades, and those that fall in between
* In the 1950s, there was the idea that depression was caused by a lack of serotonin in the synapse so that the electrical circuits don't get enough stimulation. But not everyone responds to SSRIs.
* The Brodmann area 25 (BA25) is an area of the brain that seems to regulate emotional tone, anxiety, motivation, drive, self-reflection, and sleep - all of which are dysregulated by depression.
* When this area is stimulated with Deep Brain Stimulation (DBS) patients spontaneously reported acute effects including sudden calmness or lightness, disappearance of the void, sense of heightened awareness, increased interest, connectedness and sudden brightening of the room. One woman described her illness as a complete incapacity to feel emotional, or even sensory connections.
* When we turn the DBS on, patients want to move again, but the activities that they want to do involve cleaning out rooms. Taking the trash out of the kitchen. Washing dishes.

== The Orchestrating Cell (Pancreas, Kidney, Liver + Hormones) ==

* There must be a means for one part of the body to "meet" a distant part of the bodfy. We call these signals "hormones" from the Greek hormon - to impel, or to set some actions into motion. In a sense, they impel the body to act as a whole.
* Hormones are molecules that are produced by endocrine glands, including the hypothalamus, pituitary gland, adrenal glands, gonads, (i.e., testes and ovaries), thyroid gland, parathyroid glands, and pancreas.
* The pancreas is a gland that releases juices into the digestive system, where they break down complex food molecules into simple ones. It contains the islets of Langerhans, which produce a range of hormones, including glucagon, somatostatin, and ghrelin.
* Insulin is the master regulator of sugar metabolism. It is synthesized in the pancreatic beta cells, and its secretion is stimulated by the presence of glucose in the blood. It then travels all over the body. Virtually every tissue responds to insulin: the presence of sugar means that the extraction of energy, and everything that flows from energy - the synthesis of proteins and fats, the storage of chemicals for future use, the firing of neurons, the growth of cells - can proceed. It is, perhaps, among the most important of the "long range" messages that acts as a central coordinator and orchestrates metabolism all through the body.
* Type 1 diabetes is a disease in which immune cells attack the beta-islet-cells of the pancreas. Without insulin, the body cannot sense the presence of sugar. The cells in e body, imagining that the body has no sugar, begin to scramble around for other forms of fuel. The sugar, meanwhile, spikes threateningly in the blood, and spills into the urine - cellular starvation in the presence of plenty.
* The pancreas is the central coordinator of metabolism, the maker of the hormone to which all tissues respond.

After dinner at a pizzeria:

* The carbohydrates from the bread and rigatoni are digested into sugars - ultimately into glucose. The glucose is packed up from the intestines, absorbed into blood and moved into circulation. When the blood reaches the pancreas, it sense the spike in glucose, and sends out insulin. The insulin, in turn, moves the sugar from the blood into all the cells of your body, where it can be stored, if needed, or used for energy, as needed. The brain is the ultimate recipient of these signals: if the sugar drops too low, it reacts by sending out converse signals. Yet other hormones, secreted by different cells, send signals to release stored sugars into the blood. The stores come from liver cells, which respond, at least transiently, by releasing their stockpiles of stored glucose to restore equilibrium.

* The kidney contains the nephron, which is the site where the blood and kidney cells meet, and the first drops of urine are generated. The circulation of blood carries the excess salt, dissolved in plasma to the kidneys.
* The excess sodium causes a hormonal system, regulated by the kidney and the adrenal gland, which sits just above the kidney, to decrease its signal. The cells in the tubule respond to these changes by excreting the excess sodium into urine, thereby discarding the salt and returning the sodium level to normal. The salt is also detected by specialized cells in the brain that monitor the overall concentration of salts in the blood, a property called osmolality.*
* The non-waste products? The sugar and other essential products are reabsorbed into the body by the cells in the collecting duct through special channels. We generate excess, and the pare it back to restore normalcy.

* The alcohol is treated by the cells of the liver - hepatocytes. Liver cells are specialized for both storage and waste disposal, secretion, protein syntheses, etc.
* We think of metabolism as a mechanism to generate energy. But it's also a mechanism to generate waste. The kidney dispenses some of this through urine, but the kidney is not a detoxifying plant: its master plan for waste is to merely wash it away down a sewer.
* Liver cells, in contrast, have evolved dozens of mechanisms to detoxyfy and dispense waste. Alcohol is detoxified in a series of reactions, until it is broken down into a harmless chemical

* The pancreatic cell maintains metabolic constancy, the kidneys salt constancy, the liver chemical constancy.
* The liver, pancreas, brain, and kidney are four of the principal organs of homeostasis. The pancreatic beta cells control metabolic homeostasis through the hormone insulin. The kidney's nephrons control salt and water, maintaining a constant level of salinity in the blood. The liver, among many of its functions, prevents us from being soused in toxic products, including ethanol. The brain coordinates this activity by sensing levels, sending out hormones, and acting as a master orchestrator of balance-restoration.

== The Renewing Cell (Stem Cells) ==
* On the one hand, a stem cell must generate functional "differentiated" cells; a blood stem cell, for instance, must divide to give rise to the cells that form the mature elements of blood - white cells, red cells, platelets. But it must also divide to replenish itself, ie a stem cell
* A totipotent cell can give rise to all types of cells
* A pluripotent cell can five rise to nearly all cell types
* A multipotent cell can give rise to all cell types in a particular kind of tissue.
* A single stem cell can produce billions of mature red and white cells - and an entire organ system of an animal.
* Human embryonic stem cells (h-ES cells) come from embryos discarded from IVF procedures.
* In 1998, James Thomson extracted cells from inside these embryos and grew five human cell lines - three "males" and two "females". One of these, H-9, a female, has become the standard ES cell, grown in thousands of incubators in undreds of labs around the planet, and subject to tens of thousands of experiments.
* In 2001, Bush restricted federal funding to research involving ES cells that had already been derived (such as H-9)
* There are now iPS cells (induced pluripotent stem cells) changed, using generic manipulations, from mature fibroblasts into induced pluripotent cells. The ides is you take your own cell, from your skin or blood and make it crawl backward in time and transfom it into an iPS cell, from which you can make any cell - cartilage, neurons, T cells, pancreatic beta call, without any problems of histocompatibility, because they are your own cells.

== The Repairing Cell (Bone) ==
* The skeleton grows to a point, and then knows when to stop growing. It heals itself continuously throughout adult life and repairs itself acutely after injury. It responds with sensitivity to hormones; it potentially even synthesizes its own hormones.
* It might look like a chunk of hardened calcium, but bone is in fact made of a multiplicity of cells:
** Cartilage cells - chondrocytes
** Osteoblast - deposits calcium and other proteins to form a calcified matrix in layers, and then get trapped in its own deposit to form new bone. It is the bone-making, bone-depositing cell.
** OSteoclast -are large cells with multiple nuclei that are bone eaters. They chew away on the matrix, or puch holes in it, removing and remodeling bone like constanly pruning gardeners
* There are cells at the ends of a bone - but not in its middle - that generate new cells that lengthen it.
* How does bone grow during adolescence? A special population of cells, sitting at the growth plate at the two ends of bone, shoots off cartilage and osteoblasts that allows bone to lengthen. And why does it stop growing? Because this population diminishes over time, until early adulthood, when very few are left.
* Why doesn't cartilage in joints get repaired, just as a bone fracture does, in adults? Because the repairing cells die during the injury.
* There are other organs where damage, once done, is permanent. Neurons in the brain and the spinal cord, once they've stopped dividing, don't divide to regenerate neurones (they are post-mitotic, ie no longer able to divide).

== The Selfish Cell (Cancer) ==

* A cut on your hand shows homeostasis at work. Blood leaks out. Platelets and clotting factors, induced by the tissue damage, gather around the wound. Neutrophils, sensing a danger signal, accumulate at the site as first responders to infection. They stand guard to ensure that pathogens don't get a chance to breach the boundaries of the self. A clot forms, and the wound is temporarily plugged.
* Then the healing begins. If the wound is shallow, the two ends of skin appose against themselves. If the wound is deep, fibroblasts from under the skin, crawl in to deposit a protein matrix underneath the wound. And then skin cells proliferate over the matrix to cover the wound, occasionally leaving a scar. Once they touch each other, the cells stop dividing. It takes a host of cells to coordinate this process. The wound has healed.

* In cancel, cell division is dysregulated - jammed accelerator genes and snapped brakes. The cars speed through the traffic jam, piling up on each other and causing tumors. Or they frantically move into alternate routes, causing metastasis.
* The jammed accelerators are called oncogenes. The snapped brakes are called tumor suppressors
* Any individual specimen of cancer has a permutation of mutations that is unique to it.
* The genetic programs that enable cancer cells to sustain malignant growth are shared, to some extent, with stem cells
* A tiny fraction of the bulk of leukemia cells in the marrow are capable of regenerating the whole leukemia from scratch.

== The Songs of the Cell ==

* All cells come from cells.
* The first human cells gives rise to all human tissues. Every cell in the human body can be produced, in principle, from an embryonic cell (or stem cell)
* Although cells vary widely in their form and function, there are deep physiological similarities that run through them.
* These similarities can be repurposed by cells for specialized functions. An immune cell uses its molecular apparatus for ingestion to eat microbes; a glial cell uses similar pathways to prune synapses in the brain.
* Systems of cells with specialized functions, communicating with each other through short and long-range messages, can achieve powerful physiological functions that individual cells cannot achieve - for example, the healing of wounds, the signaling of metabolic states, sentience, cognition, homeostasis, immunity. The human body functions as a citizenship of cooperating cells. The disintegration of this citizenship tips us from wellness to disease.
* Cellular physiology is thus the basis for human physiology, and cellular pathology is the basis for human pathology.
* The process of decay, repair, and rejuvenation in individual organs are idiosyncratic. Specialized cells in some organs are responsible for consistent repair and rejuvenation (blood rejuvenates through human adulthood, albeit at diminished rates), but other organs lack such cells (nerve cells rarely rejuvenate). The balance between injury/decay and repair/rejuvenation ultimately results in the integrity or defeneration of an organ.
* Beyond understanding cells in isolation, deciphering the internal laws of cellular citizenship - tolerance, communication, specialization, diversity, boundary-formation, cooperation, niches, ecological relationships - will ultimately result in the birth of a new kind of cellular medicine.
* The capacity to build new humans out of our building blocks - cells - lies very much within ghe reach of medicine today. Cellular reengineering can ameliorate, or even reverse, cellular pathology.
* Cellular engineering has already allowed us to rebuild parts of humans with reengineered cells. As our understanding grows, new medical and ethical conundrums will arise, intensifying and challenging the basic definition of who we are, and how much we wish to change ourselves.
[[Category:Science]]
[[Category:Books]]

Cells

2025-04-21T15:53:30Z

Rob: Rob moved page Cells to The Song of the Cell

#REDIRECT [[The Song of the Cell]]

The Song of the Cell

2025-04-21T15:53:30Z

Rob: Rob moved page Cells to The Song of the Cell

Books

2025-04-21T15:52:25Z

Rob: /* 2024 */

== Books to Buy ==

* Language, Thought, and other Biological Categories
* The Flat Mind
* On the Calculation of Volume - Solvej Balle
* Open Socrates - Agnes Callard
* Why Machines Learn: The Elegant Maths Behind Modern AI (out in paperback Jan 30 2025)
* A History of the Muslim World: From Its Origins to the Dawn of Modernity (awaiting paperback)
* How Life Works: A User’s Guide to the New Biology
* Stranger Than Fiction: Lives of the Twentieth-Century Novel
* Grey Matters: A Biography of Brain Surgery - not yet in paperback
* The New Roman Empire: A History of Byzantium
* Magnetic Mountain: Stalinism as Civilization
* Consolations - David Whyte

== Books to Read ==

* Reading to Learn - William Zinger
* Breakfast of Champions - Kurt Vonnegut
* A Little History of Philosophy - Nigel Warburton

== Currently Reading ==

* [[Atomic Habits]] - James Clear
* [[Das Ludwig Thoma Komplott]]- Sabine Vöhringer

== Books Read ==

=== 2025 (week 17) ===

* [[Why We Remember: Revealing the Hidden Power of Memory]] - Dr Charan Ranganath
* [[From Bacteria to Bach and Back]] - Daniel Dennett (re-read)
* [[The Village of Eight Graves]] - Seishi Yokomizo
* [[Science: A History]] - Richard Crockett
* [[Vienna: How the City of Ideas Created the Modern World]] - John Gribbin
* [[The Inugami Curse]] - Seishi Yokomizo
* [[The Rise and Reign of the Mammals]]
* [[Four Ways of Thinking]] - David Sumpter
* [[I've Been Thinking]] - Daniel Dennett
* [[Serendipities: Language and Lunacy]] - Umberto Eco
* [[I Am Dynamite: A Life of Friedrich Nietzsche]] - Sue Prideaux
* [[A Brief History of Intelligence]] - Max S. Bennett
* [[Foucault’s Pendulum]] - Umberto Eco (re-read)
* [[Kant and the Platypus]] - Umberto Eco
* [[Le cerveau m’a beaucoup déçu. L’esprit, non]] - Antoine Sénanque

=== 2024 ===

* The Plot - Will Eisner
* The Prague Cemetery - Umberto Eco
* The Nonjin Murders - Seishi Yokomizo
* When We Cease to Understand the World - Labatut
* Zen and the Art of Motorcycle Maintenance - Robert Pirsig (reread)
* The Way We Think: Conceptual Blending and the Mind’s Hidden Complexities - Fauconnier and Turner
* The Singularity is Nearer - Ray Kurzweil
* Physics and Philosophy - Werner Heisenberg
* Le Ton Beau de…
* The Origins of Creativity - Edward O Wilson
* Psychonauts -
* The MANIAC - Benjamin Labatut
* In Search of Memory - Eric R. Kandel
* Dreaming: A Very Short Introduction - Hobson
* Les Effinger - Gabriele Target
* Triad - Tom Keve
* Nietzsche - Stefan Zweig
* The Weirdest People in the World - Joseph Henrich
* How Language Works - David Crystal
* The Invention of Nature - Andrea Wolf
* [[The Song of the Cell]] - Siddhartha Mukherjee
* [[Gödel, Escher, Bach]] - Douglas Hofstadter
* [[From Bacteria to Bach and Back]] - Daniel Dennett

[[Category:Books]]

The Song of the Cell

2025-04-21T15:51:28Z

Rob: /* The Songs of the Cell */

Neuroscience

2025-04-21T15:50:28Z

Rob: /* Psychoanalysis */

Neuroscience comes from a merging of philosophy, psychology, and psychoanalysis with the biology of the brain to produce a new science based on five principles:
* Mind and brain are inseparable
* Each mental function is carried out by specialized neural circuits in different regions of the brain
* All these circuits are made up of the same elementary signaling units, the nerve cells
* The neural circuits use specific molecules to generate signals within and between nerve cells
* These specific signaling molecules have been conserved through millions of years of evolution.

Before molecular biology:
* Darwinian evolution
* Genetic basis of the inheritance of bodily form and mental traits
* Cells as the basic unit of all living things

Molecular biology united those three ideas by focusing on the actions of genes and proteins in individual cells. It recognized the gene as the unit of heredity, and the products of the genes, the proteins, as the elements of cellular function.

Emergence of the new biology of mind:
* In the 1960s, the philosophy of mind, behaviorist psychology (simple behavior in animals, and cognitive psychology (complex phenomena in people) merged, giving rise to modern cognitive psychology.
* In the 1970s, cognitive psychology, the science of mind, merged with neuroscience, the science of the brain, to create cognitive neuroscience

== Behaviorism ==

Pavlov discovered worked on:
* classical conditioning - an animal is taught to associate a behavioral response with itsconsequences
* habituation - animal gets used to a stimulus and learns to ignore it
* sensitization

BF Skinner continued, focusing exclusively on observable behaviors

== Parts of the Brain ==

== Psychoanalysis ==
[[Category:Consciousness]]
[[Category:Science]]

Science

2025-04-21T15:48:21Z

Rob: /* Neuroscience and Psychology */

Science, can be broadly categorized into three major groups:

== Natural Sciences ==
* Physics - The foundation of all natural sciences, exploring fundamental concepts like matter, energy, motion, force, space, and time, and including subfields such as:
** Classical mechanics (motion of objects)
** Thermodynamics (heat and energy)
** Electromagnetism (electricity and magnetism)
** Optics (light and its behavior)
** Quantum mechanics (behavior of subatomic particles)
** Astrophysics (physics of the universe)
* Chemistry - Investigates the composition, structure, properties, and changes of matter, studying atoms, molecules, and their interactions, and including subfields such as:
** Organic chemistry (carbon-containing compounds)
** Inorganic chemistry (non-carbon compounds)
** Biochemistry (chemistry of living organisms)
* Biology - The study of living organisms and their vital processes, exploring life forms from microorganisms to complex ecosystems, and including subfields such as:
** Botany (plant biology)
** Zoology (animal biology)
** Microbiology (microscopic organisms)
** Genetics (heredity and variation)
** Ecology (interactions between organisms and their environment)
* Earth Science - Examines the Earth's physical and chemical composition, its history, and the processes that shape it, and including subfields such as:
** Geology (study of rocks, minerals, and the Earth's structure)
** Oceanography (study of the oceans)
** Meteorology (study of the atmosphere and weather)
** Climatology (study of long-term weather patterns)
*** Seismology (study of earthquakes)
*** Paleontology (study of fossils and ancient life)
** Astronomy - The study of celestial objects and phenomena, exploring stars, planets, galaxies, and the universe as a whole, and including subfields such as:
** Astrophysics (physics of the universe)
** Cosmology (origin and evolution of the universe)
== Formal Sciences ==
* Mathematics - The abstract study of numbers, shapes, structures, and relationships, and including subfields such as algebra, geometry, calculus, statistics, and many more.
* Logic - The systematic study of valid reasoning and argumentation.
* Computer Science - The study of computation, including algorithms, data structures, programming languages, and the design of computer systems.
== Social Sciences ==
* Psychology - The scientific study of the mind and behavior, exploring human cognition, emotion, and social interaction.
* Sociology - The systematic study of human societies, including their origins, structures, interactions, and development.
* Anthropology - The study of human societies and cultures, including their history, beliefs, customs, and social organization.
* Economics - The study of production, distribution, and consumption of goods and services.
* Political Science - The study of government, political systems, and political behavior.
* History - The study of past events, including human societies, cultures, and civilizations.
== Neuroscience and Psychology ==
Psychology and neuroscience are closely related fields that both seek to understand the human mind and behavior, but they approach this from different angles. In essence:
* Neuroscience provides the "hardware" – the brain structures and neural processes. It studies the nervous system, primarily the brain and its functions, employing techniques like brain imaging (MRI, fMRI, PET), electrophysiology (EEG), and genetic analysis to investigate how the brain structures and neural activity underlie mental processes and to understand the biological basis of behavior, cognition, and emotion.
* Psychology explores the "software" – the mental processes and behaviors that emerge from brain activity. It studies human behavior and mental processes, including thoughts, feelings, perceptions, and actions, using a variety of methods, including experiments, observations, surveys, and case studies, to investigate human behavior and mental processes, and to understand, explain, predict, and influence human behavior.

Neuroscience provides a biological foundation for psychological phenomena. For example, neuroscience research can help explain the neural mechanisms underlying memory, learning, emotions, and disorders like depression and anxiety.

The field of cognitive neuroscience specifically bridges the gap between psychology and neuroscience. It investigates how brain activity relates to cognitive functions such as attention, memory, language, and decision-making.

Psychological research can inform neuroscience by providing hypotheses about brain function and suggesting areas for further investigation. Neuroscience findings can, in turn, refine and expand psychological theories.
[[Category:Science]]

History

2025-04-21T15:47:54Z

Rob: /* Contemporary History */

This is the intro to history

== Cosmological History ==

* -13.8bn - Big Bang (Big Bounce?)
* -4.5bn - Earth formed

== Evolutionary History ==

* -4b - Single-celled life
* -3.5b - Photosynthesis
* -2b - Eukaryotes
* -1.6b - Multi-Celled Life
* -1.5b - Fungi
* -800m - Plants
* -700m - Animals
* -538m - Cambrian Explosion
* -518m - Vertebrates
* -390m - Tetrapods
* -243m - Dinosaurs
* -170m - Mammals
* -85m - Primates
* -2.3 - Homo Habilis
* -2m - Homo Erectus
* -300k - Homo Sapiens

See also [[The Ancestor's Tale]].

== Prehistory ==

* -130k-100k - Out of Africa
* - 11.7k - Neolithic/First Agricultural Revolution

== Ancient History ==

* 4000 BCE - Development of City States
* 3000 BCE - Writing
* 427-348 BCE - Plato
* 384-322 BCE - Aristotle
* c300 BCE - Euclid
* 287-212 BCE Archimedes

== Medieval History ==
* 476 - Fall of the Roman Empire
* 1347-1351 - Black Death

== Modern History ==
* 14th-16th C - Renaissance
* 1450s - Gutenberg and moveable type
* 1473-1543 - Copernicus and Heliocentrism
* 1492 - Columbus' voyage to the Americas
* 1517 - Luther and the Reformation
* 1543 - Copernicus and the Scientific Revolution
* 1618-1648 - Thirty Years War
* 1687 - Newton's Principia Mathematica
* 1765–1783 - The American Revolution
* 1780s on - Industrial Revolution
* 1789-1799 - The French Revolution
* 1799-1815 - The Napoleonic Era

== Contemporary History ==
[[Category:History]]

Project

2025-04-21T15:44:17Z

Rob: /* Minds */

== Thinking About Minds ==

I’m interested in getting to grips with four main things:
* How did life evolve up to the point of producing modern human brains (13.4bn ya to 40,000 ya)
* How did human culture develop to bring us to the current day
* How do we interpret and interact with the world via our brains
* Where are we going now (with a particular focus on screens, democracy, AI, and climate change)

== Big Bang to Brains ==

=== 13.8bn ya: The Big Bang and the Birth of the Universe ===

The Big Bang is, we presume, the cataclysmic event that gave birth to the universe. In an instant, all the energy and matter of the universe were concentrated into an infinitely small point, and then began to expand and cool, leading to the formation of atoms of the first, lightest, atoms - primarily hydrogen and helium and maybe some lithium.

Over millions of years, gravity caused these atoms to come together in vast gas clouds that eventually ignited to create the first stars. The stars forged heavier elements in their cores. These elements, like carbon, oxygen, and nitrogen are the building blocks of life and, when these stars died, they exploded in spectacular supernovae, scattering the elements across the cosmos.

=== 4.6bn ya: Formation of Planets and the Emergence of Life ===

About 4.6 billion years ago, our solar system formed from a cloud of gas and dust left over from previous generations of stars. At the center of this swirling cloud, the sun ignited, and the remaining material coalesced to form the planets, including Earth.

=== 3.8bn ya: Emergence of Life on Earth ===

The mechanisms through which life emerged on Earthare still debated, but we believe that simple organic molecules formed in the primordial oceans and eventually self-assembled into the first self-replicating structures. These early life forms were simple, single-celled organisms, but they were the ancestors of all life on Earth today.

=== 540m ya: The Cambrian Explosion ===

For billions of years, life on Earth remained relatively simple. But then, about 540 million years ago, a burst of evolutionary innovation known as the Cambrian explosion occurred. During this period, a remarkable diversity of multicellular organisms appeared, with complex body plans and new features like eyes and skeletons.

Over the next hundreds of millions of years, life continued to evolve and diversify, driven by natural selection. Fish evolved into amphibians, amphibians into reptiles, and reptiles into birds and mammals.

=== 65m ya: The Rise of Mammals and Primates ===

About 65 million years ago, a mass extinction event wiped out the dinosaurs, paving the way for the rise of mammals, which diversified rapidly, evolving into a wide range of forms, from whales to bats to primates.

Primates, which include monkeys, apes, and humans, evolved about 55 million years ago, and started as small, tree-dwelling creatures with grasping hands and feet, and forward-facing eyes that provided depth perception.

=== 6m ya: The Emergence of Humans ===

The human lineage diverged from the chimpanzee lineage about 6-7 million years ago. The first hominins, the group that includes humans and our extinct ancestors, were bipedal, an adaptation that freed their hands for other tasks, such as carrying objects and using tools.

Over millions of years, hominin brains gradually increased in size and complexity. This increase in brain size was accompanied by the development of new cognitive abilities, such as language, abstract thought, and problem-solving.

=== 300k ya: Homo Sapiens / Modern Humans ===

Homo sapiens appeared about 300,000 years ago. We are characterized by our large brains, complex language abilities, and capacity for symbolic thought, and are the only hominin species that has survived to the present day.

Our brains contain the most complex structures in the known universe, with about 86 billion neurons, each connected to thousands of other neurons, forming a vast network that allows us to perceive the world around us, learn and remember information, and engage in complex thought and behavior.

Several factors are believed to have contributed to the evolution of the human brain, including:

* Bipedalism - Walking on two legs freed our hands and allowed for the development of tool use, which in turn stimulated brain development.
* Diet - A shift towards a more meat-rich diet provided the extra energy needed to fuel a larger brain.
* Social interaction - Living in complex social groups required advanced cognitive abilities, such as recognizing individuals, understanding social hierarchies, and cooperating with others.
* Language - The development of language allowed for more complex communication and the transmission of knowledge across generations.

== Stones to Screens ==

Once the modern human brains was in place, how did we come to construct the societies where we are today.

=== 300k-50k ya: The Dawn of Humanity ===

Homo sapiens emerged in Africa around 300,000 years ago andlived in small, nomadic groups, hunting and gathering for survival. They were deeply intertwined with the natural world, and their culture likely revolved around animistic beliefs, with reverence for animals, natural forces, and the cycles of life and death.

Around 1 million years ago, Homo erectus had tamed fire, but its widespread us began around this period, providing warmth, protection from predators, and allowed for cooking, which improved nutrition and facilitated social gatherings.

We also have evidence of symbolic thought, including the use of ochre for body painting and the creation of simple ornaments, suggesting the development of self-awareness, social identity, and perhaps early forms of ritualistic behavior.

=== 50k-10k ya: The Great Leap Forward ===

During this period, there was a significant acceleration in human cultural and technological development, including:
* Advanced toolmaking - The development of more sophisticated stone tools, such as blades and projectile points, improved hunting efficiency and resource utilization.
* Art and symbolic expression - Cave paintings, such as those found in Lascaux and Altamira, showcase remarkable artistic skill and symbolic thinking. These works may have served ritualistic, communicative, or educational purposes.
* Expansion across the globe - Humans migrated out of Africa and populated nearly all continents, adapting to diverse environments and developing unique cultural traditions.

=== 10k-4k ya: The Neolithic Revolution ===

During this period, agriculture was developed and plants and animals were domesticated:
* Settled life - The shift from nomadic hunter-gathering to settled agriculture led to the establishment of permanent villages and later towns. This had profound social and cultural implications, including increased population density, specialization of labor, and the development of social hierarchies.
* Pottery and weaving - The invention of pottery allowed for food storage and cooking, while weaving provided clothing and other textiles.
* Emergence of early civilizations - In fertile river valleys like Mesopotamia and the Nile Valley, complex societies arose with organized governments, monumental architecture, writing systems, and advanced technologies.

=== 4k ya - 500 CE: The Rise of Civilizations ===

During this period, numerous civilizations flourished across the globe, contributing various technical and cultural advances:
* Writing - Such as cuneiform in Mesopotamia and hieroglyphics in Egypt, enabled the recording of knowledge, history, and literature.
* Urbanization and state formation - Cities grew into centers of trade, culture, and political power, leading to the development of complex state structures and empires.
* Technological advancements - In metallurgy, mathematics, astronomy, and engineering, lead to innovations like the wheel, irrigation systems, and monumental architecture.
* Religions and philosophies - Including Buddhism, Confucianism, Judaism, and Christianity, emerge - shaping ethical values, social norms, and cultural identities.

=== 500 - 1500 CE: The Middle Ages ===

During this period, there were significant cultural and political transformations across the world. Christianity and Islam expanded rapidly, influencing vast regions and shaping cultural landscapes. Powerful empires emerged, such as the Byzantine Empire, the Islamic Caliphates, and the Mongol Empire, connecting diverse cultures and facilitating trade and exchange.

Despite political turmoil, significant advancements were made in art, literature, science, and philosophy, particularly in the Islamic world and China.

=== 1300 - 1700 CE: The Renaissance and the Age of Exploration ===

This era marked a renewed interest in classical art, literature, and philosophy in Europe, leading to a period of intellectual and artistic flourishing:
* A focus on human potential and achievement led to significant advancements in art, science, and literature.
* European powers embarked on voyages of exploration, leading to increased global interconnectedness and the exchange of goods, ideas, and cultures.
* New discoveries in astronomy, physics, and other sciences challenged traditional beliefs and laid the foundation for modern science.

=== 1700 - 1900 CE: The Age of Revolutions and the Industrial Revolution ===

This period witnessed profound political, social, and economic transformations, driven by revolutionary ideas and technological advancements:
* Enlightenment ideals of liberty, equality, and human rights fueled revolutions in America and France, challenging traditional forms of authority.
* The Industrial Revolution bought technological innovations, such as the steam engine and the power loom, led to mass production, urbanization, and significant social changes.
* The rise of nationalism and imperialism led to the formation of new nations, while European powers expanded their colonial empires across the globe.

=== The 20th and 21st Centuries ===

This era has been marked by rapid technological advancements, globalization, and significant social and political changes:
* Two world wars and numerous other conflicts reshaped the global political landscape and led to the formation of international organizations like the United Nations.
* Rapid advancements in transportation, communication, and information technology have led to increased global interconnectedness and transformed human life.
* Globalization and and the flow of goods, ideas, and people across borders has led to increased cultural exchange and the emergence of a global culture.
* Social and political movementsfor civil rights, women's rights, and environmental protection have challenged social norms and led to significant social and political changes.

== Brains and Minds ==

What is consciousness? How do we understand and interact with the world

== The Future ==

Is a future of progress assured? Will AI help or destroy us? Will we lose critical thinking skills? Are we slowly being ushered into a matrix-like state of screen addiction?

Brain

2025-04-21T10:03:01Z

Rob: /* Brain Parts */

== Evolution of the Brain ==
[[Evolution of the Brain]]

== Brain Components ==
Three main regions based on location:
* The Forebrain (Prosencephalon) - Front and upper regions, responsible for higher-level functions
** Cerebrum - Two hemispheres, each covered by the cerebral cortex, which is responsible for complex cognitive functions. Separated into four lobes from front to back:
*** Frontal Lobe - Responsible for planning, decision-making, voluntary movement, language (Broca's area), and personality ([https://neurotorium.org/tool/brain-atlas/#telencephalon:-frontal-lobe Frontal Lobe])
*** Parietal Lobe - Processes sensory information such as touch, temperature, pain, and spatial awareness ([https://neurotorium.org/tool/brain-atlas/#telencephalon:-parietal-lobe Parietal Lobe]
*** Temporal Lobe - Primarily involved in hearing, memory, language (Wernicke's area), and processing emotions ([https://neurotorium.org/tool/brain-atlas/#telencephalon:-temporal-lobe Temporal Lobe]
**** Hippocampus - Memory formation ([https://neurotorium.org/tool/brain-atlas/#cerebral-cortex:-hippocampus Hippocampus]
**** Amygdala - Emotions ([https://neurotorium.org/tool/brain-atlas/#basal-ganglia:-amygdala Amygdala]
*** Occipital Lobe - Processing visual information ([https://neurotorium.org/tool/brain-atlas/#telencephalon:-occipital-lobe Occipital Lobe])
*** Corpus callosum - Bundle of nerve fibres connecting the two hemispheres ([https://neurotorium.org/tool/brain-atlas/#epithalamus:-pineal-gland Corpus callosum])
** Diencephalon - Situated beneath the cerebrum ([https://neurotorium.org/tool/brain-atlas/#diencephalon Diencephalon]):
*** Thalamus - A relay station for sensory and motor information going to and from the cerebral cortex. Also plays a role in consciousness, sleep, and alertness ([https://neurotorium.org/tool/brain-atlas/#diencephalon:-thalamus Thalamus])
*** Hypothalamus - Regulates bodily functions like temperature, hunger, thirst, sleep-wake cycles, and hormone release. Connects the nervous system to the endocrine system via the pituitary gland ([https://neurotorium.org/tool/brain-atlas/#diencephalon:-hypothalamus Hypothalamus])
*** Pineal Gland - regulates sleep-wake cycles through the secretion of melatonin. ([https://neurotorium.org/tool/brain-atlas/#epithalamus:-pineal-gland Pineal Gland])
* The Midbrain (Mesencephalon) - Located beneath the forebrain, acts as a relay center for sensory and motor information and plays a role in motor control, vision, hearing, and sleep-wake cycles.
** Superior colliculi - Controls head movements in reponse to visual input and coordinates eye movements ([https://neurotorium.org/tool/brain-atlas/#mesencephalon:-superior-colliculus Superior colliculi])
** Inferior colliculi - Controls head movements in reponse to auditory input ([https://neurotorium.org/tool/brain-atlas/#mesencephalon:-inferior-colliculus Inferior colliculi])
** Substantia nigra - Motor function ([https://neurotorium.org/tool/brain-atlas/#mesencephalon:-substantia-nigra Substantia nigra])
* The Hindbrain (Rhomencephalon) - Located at the bak and lower part of the brain, connecting to the spinal cord, crucial for many basic life functions:
** Cerebellum - Behind the brainstem, responsible for coordinating voluntary movement, posture, balance, and motor learning ([https://neurotorium.org/tool/brain-atlas/#cerebellum Cerebellum])
** Brainstem - Connects the cerebrum and cerebellum to the spinal cord:
*** Pons - regulates breathing, plays roles in sleep and facial expressions ([https://neurotorium.org/tool/brain-atlas/#brain-stem:-pons Pons])
*** Medulla Oblongate - controls heart rate, breathing, blood pressure and relexes like vomiting, coughing, and swallowing ([https://neurotorium.org/tool/brain-atlas/#brain-stem:-medulla-oblongata Medulla Oblongate])

* [[Cerebral Hemispheres/Cerebral Cortex]] - concerned with higher mental functions: perception, action, language, and planning. Contains about 100 billion neurons, each with about a thousand synapses, making a total of about 100 trillion synaptic connections
** Frontal lobe - part of the neural circuit governing social judgements, planning and organization of activities, aspects of language, control of movement, and a form of short-term memory called working memory
** Parietal lobe - receives sensory information about touch, pressure, and space around the body and helps integrate that information into coherent perceptions
*** somatosensory cortex - a strip in the parietal lobe contains Wilder Penfield's sensory homunculus.
** Occipital lobe in involved in vision
** Temporal lobe is involved with auditory processing and aspects of language and memory.
** Basal ganglia - help regulate motor performance
** Hippocampus - involved with aspects of memory storage
** Amygdala - coordinates autonomic and endocrine responses in the context of emotional states

== Brain Functions ==
The brain provides coherent control over the actions of an animal. Information from the sense organs is collected in the brain, where it is processed to extract information about the structure of the environment. It combines the processed information with info about the current needs of the animal and with memory of past circumstances, and then generates motor responses. The main functions are:
* Perception - The brain collects info from the senses.
* Motor control - Motor systems are areas of the brain, mainly in the spinal cord and hindbrain, that initiate body movements by activating muscles.
* Sleep - The brain controls the transitions from sleeping to waking in a daily cycle
* Homeostasis - maintaining parameters (such as temperature, water content, salt concentration in the bloodstream, blood glucose levels, blood oxygen level) within a limited range of variation, through negative feedback
* Motivation - The brain activates behaviors to meet any needs that arise, generally through a reward-punishment mechanism. The basal ganglia inihibit most of the motor systems in the brain, and then release the inhibition for a specific motor system to allow its action to be carried out.
* Learning and memory - modifying behavior based on experience:
** Working memory - maintaining a temporary representation of information about the task that you are currently working on
** Episodic memory - remembering the details of specific events. The [[Hippocampus]] is heavily involved.
** Semantic memory - remembering facts and relationships. Mainly in the [[Cerebral Cortex]]
** Instrumental learning - allowing rewards and punishments to modify behavior
** Motor learning - refining patterns of body movement by practicing or repetition

[[Category:Consciousness]]

Project

2025-04-21T08:55:12Z

Rob: /* The Future */

== Thinking About Minds ==

I’m interested in getting to grips with four main things:
* How did life evolve up to the point of producing modern human brains (13.4bn ya to 40,000 ya)
* How did human culture develop to bring us to the current day
* How do we interpret and interact with the world via our brains
* Where are we going now (with a particular focus on screens, democracy, AI, and climate change)

== Big Bang to Brains ==

=== 13.8bn ya: The Big Bang and the Birth of the Universe ===

The Big Bang is, we presume, the cataclysmic event that gave birth to the universe. In an instant, all the energy and matter of the universe were concentrated into an infinitely small point, and then began to expand and cool, leading to the formation of atoms of the first, lightest, atoms - primarily hydrogen and helium and maybe some lithium.

Over millions of years, gravity caused these atoms to come together in vast gas clouds that eventually ignited to create the first stars. The stars forged heavier elements in their cores. These elements, like carbon, oxygen, and nitrogen are the building blocks of life and, when these stars died, they exploded in spectacular supernovae, scattering the elements across the cosmos.

=== 4.6bn ya: Formation of Planets and the Emergence of Life ===

About 4.6 billion years ago, our solar system formed from a cloud of gas and dust left over from previous generations of stars. At the center of this swirling cloud, the sun ignited, and the remaining material coalesced to form the planets, including Earth.

=== 3.8bn ya: Emergence of Life on Earth ===

The mechanisms through which life emerged on Earthare still debated, but we believe that simple organic molecules formed in the primordial oceans and eventually self-assembled into the first self-replicating structures. These early life forms were simple, single-celled organisms, but they were the ancestors of all life on Earth today.

=== 540m ya: The Cambrian Explosion ===

For billions of years, life on Earth remained relatively simple. But then, about 540 million years ago, a burst of evolutionary innovation known as the Cambrian explosion occurred. During this period, a remarkable diversity of multicellular organisms appeared, with complex body plans and new features like eyes and skeletons.

Over the next hundreds of millions of years, life continued to evolve and diversify, driven by natural selection. Fish evolved into amphibians, amphibians into reptiles, and reptiles into birds and mammals.

=== 65m ya: The Rise of Mammals and Primates ===

About 65 million years ago, a mass extinction event wiped out the dinosaurs, paving the way for the rise of mammals, which diversified rapidly, evolving into a wide range of forms, from whales to bats to primates.

Primates, which include monkeys, apes, and humans, evolved about 55 million years ago, and started as small, tree-dwelling creatures with grasping hands and feet, and forward-facing eyes that provided depth perception.

=== 6m ya: The Emergence of Humans ===

The human lineage diverged from the chimpanzee lineage about 6-7 million years ago. The first hominins, the group that includes humans and our extinct ancestors, were bipedal, an adaptation that freed their hands for other tasks, such as carrying objects and using tools.

Over millions of years, hominin brains gradually increased in size and complexity. This increase in brain size was accompanied by the development of new cognitive abilities, such as language, abstract thought, and problem-solving.

=== 300k ya: Homo Sapiens / Modern Humans ===

Homo sapiens appeared about 300,000 years ago. We are characterized by our large brains, complex language abilities, and capacity for symbolic thought, and are the only hominin species that has survived to the present day.

Our brains contain the most complex structures in the known universe, with about 86 billion neurons, each connected to thousands of other neurons, forming a vast network that allows us to perceive the world around us, learn and remember information, and engage in complex thought and behavior.

Several factors are believed to have contributed to the evolution of the human brain, including:

* Bipedalism - Walking on two legs freed our hands and allowed for the development of tool use, which in turn stimulated brain development.
* Diet - A shift towards a more meat-rich diet provided the extra energy needed to fuel a larger brain.
* Social interaction - Living in complex social groups required advanced cognitive abilities, such as recognizing individuals, understanding social hierarchies, and cooperating with others.
* Language - The development of language allowed for more complex communication and the transmission of knowledge across generations.

== Stones to Screens ==

Once the modern human brains was in place, how did we come to construct the societies where we are today.

=== 300k-50k ya: The Dawn of Humanity ===

Homo sapiens emerged in Africa around 300,000 years ago andlived in small, nomadic groups, hunting and gathering for survival. They were deeply intertwined with the natural world, and their culture likely revolved around animistic beliefs, with reverence for animals, natural forces, and the cycles of life and death.

Around 1 million years ago, Homo erectus had tamed fire, but its widespread us began around this period, providing warmth, protection from predators, and allowed for cooking, which improved nutrition and facilitated social gatherings.

We also have evidence of symbolic thought, including the use of ochre for body painting and the creation of simple ornaments, suggesting the development of self-awareness, social identity, and perhaps early forms of ritualistic behavior.

=== 50k-10k ya: The Great Leap Forward ===

During this period, there was a significant acceleration in human cultural and technological development, including:
* Advanced toolmaking - The development of more sophisticated stone tools, such as blades and projectile points, improved hunting efficiency and resource utilization.
* Art and symbolic expression - Cave paintings, such as those found in Lascaux and Altamira, showcase remarkable artistic skill and symbolic thinking. These works may have served ritualistic, communicative, or educational purposes.
* Expansion across the globe - Humans migrated out of Africa and populated nearly all continents, adapting to diverse environments and developing unique cultural traditions.

=== 10k-4k ya: The Neolithic Revolution ===

During this period, agriculture was developed and plants and animals were domesticated:
* Settled life - The shift from nomadic hunter-gathering to settled agriculture led to the establishment of permanent villages and later towns. This had profound social and cultural implications, including increased population density, specialization of labor, and the development of social hierarchies.
* Pottery and weaving - The invention of pottery allowed for food storage and cooking, while weaving provided clothing and other textiles.
* Emergence of early civilizations - In fertile river valleys like Mesopotamia and the Nile Valley, complex societies arose with organized governments, monumental architecture, writing systems, and advanced technologies.

=== 4k ya - 500 CE: The Rise of Civilizations ===

During this period, numerous civilizations flourished across the globe, contributing various technical and cultural advances:
* Writing - Such as cuneiform in Mesopotamia and hieroglyphics in Egypt, enabled the recording of knowledge, history, and literature.
* Urbanization and state formation - Cities grew into centers of trade, culture, and political power, leading to the development of complex state structures and empires.
* Technological advancements - In metallurgy, mathematics, astronomy, and engineering, lead to innovations like the wheel, irrigation systems, and monumental architecture.
* Religions and philosophies - Including Buddhism, Confucianism, Judaism, and Christianity, emerge - shaping ethical values, social norms, and cultural identities.

=== 500 - 1500 CE: The Middle Ages ===

During this period, there were significant cultural and political transformations across the world. Christianity and Islam expanded rapidly, influencing vast regions and shaping cultural landscapes. Powerful empires emerged, such as the Byzantine Empire, the Islamic Caliphates, and the Mongol Empire, connecting diverse cultures and facilitating trade and exchange.

Despite political turmoil, significant advancements were made in art, literature, science, and philosophy, particularly in the Islamic world and China.

=== 1300 - 1700 CE: The Renaissance and the Age of Exploration ===

This era marked a renewed interest in classical art, literature, and philosophy in Europe, leading to a period of intellectual and artistic flourishing:
* A focus on human potential and achievement led to significant advancements in art, science, and literature.
* European powers embarked on voyages of exploration, leading to increased global interconnectedness and the exchange of goods, ideas, and cultures.
* New discoveries in astronomy, physics, and other sciences challenged traditional beliefs and laid the foundation for modern science.

=== 1700 - 1900 CE: The Age of Revolutions and the Industrial Revolution ===

This period witnessed profound political, social, and economic transformations, driven by revolutionary ideas and technological advancements:
* Enlightenment ideals of liberty, equality, and human rights fueled revolutions in America and France, challenging traditional forms of authority.
* The Industrial Revolution bought technological innovations, such as the steam engine and the power loom, led to mass production, urbanization, and significant social changes.
* The rise of nationalism and imperialism led to the formation of new nations, while European powers expanded their colonial empires across the globe.

=== The 20th and 21st Centuries ===

This era has been marked by rapid technological advancements, globalization, and significant social and political changes:
* Two world wars and numerous other conflicts reshaped the global political landscape and led to the formation of international organizations like the United Nations.
* Rapid advancements in transportation, communication, and information technology have led to increased global interconnectedness and transformed human life.
* Globalization and and the flow of goods, ideas, and people across borders has led to increased cultural exchange and the emergence of a global culture.
* Social and political movementsfor civil rights, women's rights, and environmental protection have challenged social norms and led to significant social and political changes.

== Minds ==

What is consciousness? How do we understand and interact with the world

== The Future ==

Is a future of progress assured? Will AI help or destroy us? Will we lose critical thinking skills? Are we slowly being ushered into a matrix-like state of screen addiction?

Project

2025-04-21T08:52:53Z

Rob: /* Thinking About Minds */

== Thinking About Minds ==

I’m interested in getting to grips with four main things:
* How did life evolve up to the point of producing modern human brains (13.4bn ya to 40,000 ya)
* How did human culture develop to bring us to the current day
* How do we interpret and interact with the world via our brains
* Where are we going now (with a particular focus on screens, democracy, AI, and climate change)

== Big Bang to Brains ==

=== 13.8bn ya: The Big Bang and the Birth of the Universe ===

The Big Bang is, we presume, the cataclysmic event that gave birth to the universe. In an instant, all the energy and matter of the universe were concentrated into an infinitely small point, and then began to expand and cool, leading to the formation of atoms of the first, lightest, atoms - primarily hydrogen and helium and maybe some lithium.

Over millions of years, gravity caused these atoms to come together in vast gas clouds that eventually ignited to create the first stars. The stars forged heavier elements in their cores. These elements, like carbon, oxygen, and nitrogen are the building blocks of life and, when these stars died, they exploded in spectacular supernovae, scattering the elements across the cosmos.

=== 4.6bn ya: Formation of Planets and the Emergence of Life ===

About 4.6 billion years ago, our solar system formed from a cloud of gas and dust left over from previous generations of stars. At the center of this swirling cloud, the sun ignited, and the remaining material coalesced to form the planets, including Earth.

=== 3.8bn ya: Emergence of Life on Earth ===

The mechanisms through which life emerged on Earthare still debated, but we believe that simple organic molecules formed in the primordial oceans and eventually self-assembled into the first self-replicating structures. These early life forms were simple, single-celled organisms, but they were the ancestors of all life on Earth today.

=== 540m ya: The Cambrian Explosion ===

For billions of years, life on Earth remained relatively simple. But then, about 540 million years ago, a burst of evolutionary innovation known as the Cambrian explosion occurred. During this period, a remarkable diversity of multicellular organisms appeared, with complex body plans and new features like eyes and skeletons.

Over the next hundreds of millions of years, life continued to evolve and diversify, driven by natural selection. Fish evolved into amphibians, amphibians into reptiles, and reptiles into birds and mammals.

=== 65m ya: The Rise of Mammals and Primates ===

About 65 million years ago, a mass extinction event wiped out the dinosaurs, paving the way for the rise of mammals, which diversified rapidly, evolving into a wide range of forms, from whales to bats to primates.

Primates, which include monkeys, apes, and humans, evolved about 55 million years ago, and started as small, tree-dwelling creatures with grasping hands and feet, and forward-facing eyes that provided depth perception.

=== 6m ya: The Emergence of Humans ===

The human lineage diverged from the chimpanzee lineage about 6-7 million years ago. The first hominins, the group that includes humans and our extinct ancestors, were bipedal, an adaptation that freed their hands for other tasks, such as carrying objects and using tools.

Over millions of years, hominin brains gradually increased in size and complexity. This increase in brain size was accompanied by the development of new cognitive abilities, such as language, abstract thought, and problem-solving.

=== 300k ya: Homo Sapiens / Modern Humans ===

Homo sapiens appeared about 300,000 years ago. We are characterized by our large brains, complex language abilities, and capacity for symbolic thought, and are the only hominin species that has survived to the present day.

Our brains contain the most complex structures in the known universe, with about 86 billion neurons, each connected to thousands of other neurons, forming a vast network that allows us to perceive the world around us, learn and remember information, and engage in complex thought and behavior.

Several factors are believed to have contributed to the evolution of the human brain, including:

* Bipedalism - Walking on two legs freed our hands and allowed for the development of tool use, which in turn stimulated brain development.
* Diet - A shift towards a more meat-rich diet provided the extra energy needed to fuel a larger brain.
* Social interaction - Living in complex social groups required advanced cognitive abilities, such as recognizing individuals, understanding social hierarchies, and cooperating with others.
* Language - The development of language allowed for more complex communication and the transmission of knowledge across generations.

== Stones to Screens ==

Once the modern human brains was in place, how did we come to construct the societies where we are today.

=== 300k-50k ya: The Dawn of Humanity ===

Homo sapiens emerged in Africa around 300,000 years ago andlived in small, nomadic groups, hunting and gathering for survival. They were deeply intertwined with the natural world, and their culture likely revolved around animistic beliefs, with reverence for animals, natural forces, and the cycles of life and death.

Around 1 million years ago, Homo erectus had tamed fire, but its widespread us began around this period, providing warmth, protection from predators, and allowed for cooking, which improved nutrition and facilitated social gatherings.

We also have evidence of symbolic thought, including the use of ochre for body painting and the creation of simple ornaments, suggesting the development of self-awareness, social identity, and perhaps early forms of ritualistic behavior.

=== 50k-10k ya: The Great Leap Forward ===

During this period, there was a significant acceleration in human cultural and technological development, including:
* Advanced toolmaking - The development of more sophisticated stone tools, such as blades and projectile points, improved hunting efficiency and resource utilization.
* Art and symbolic expression - Cave paintings, such as those found in Lascaux and Altamira, showcase remarkable artistic skill and symbolic thinking. These works may have served ritualistic, communicative, or educational purposes.
* Expansion across the globe - Humans migrated out of Africa and populated nearly all continents, adapting to diverse environments and developing unique cultural traditions.

=== 10k-4k ya: The Neolithic Revolution ===

During this period, agriculture was developed and plants and animals were domesticated:
* Settled life - The shift from nomadic hunter-gathering to settled agriculture led to the establishment of permanent villages and later towns. This had profound social and cultural implications, including increased population density, specialization of labor, and the development of social hierarchies.
* Pottery and weaving - The invention of pottery allowed for food storage and cooking, while weaving provided clothing and other textiles.
* Emergence of early civilizations - In fertile river valleys like Mesopotamia and the Nile Valley, complex societies arose with organized governments, monumental architecture, writing systems, and advanced technologies.

=== 4k ya - 500 CE: The Rise of Civilizations ===

During this period, numerous civilizations flourished across the globe, contributing various technical and cultural advances:
* Writing - Such as cuneiform in Mesopotamia and hieroglyphics in Egypt, enabled the recording of knowledge, history, and literature.
* Urbanization and state formation - Cities grew into centers of trade, culture, and political power, leading to the development of complex state structures and empires.
* Technological advancements - In metallurgy, mathematics, astronomy, and engineering, lead to innovations like the wheel, irrigation systems, and monumental architecture.
* Religions and philosophies - Including Buddhism, Confucianism, Judaism, and Christianity, emerge - shaping ethical values, social norms, and cultural identities.

=== 500 - 1500 CE: The Middle Ages ===

During this period, there were significant cultural and political transformations across the world. Christianity and Islam expanded rapidly, influencing vast regions and shaping cultural landscapes. Powerful empires emerged, such as the Byzantine Empire, the Islamic Caliphates, and the Mongol Empire, connecting diverse cultures and facilitating trade and exchange.

Despite political turmoil, significant advancements were made in art, literature, science, and philosophy, particularly in the Islamic world and China.

=== 1300 - 1700 CE: The Renaissance and the Age of Exploration ===

This era marked a renewed interest in classical art, literature, and philosophy in Europe, leading to a period of intellectual and artistic flourishing:
* A focus on human potential and achievement led to significant advancements in art, science, and literature.
* European powers embarked on voyages of exploration, leading to increased global interconnectedness and the exchange of goods, ideas, and cultures.
* New discoveries in astronomy, physics, and other sciences challenged traditional beliefs and laid the foundation for modern science.

=== 1700 - 1900 CE: The Age of Revolutions and the Industrial Revolution ===

This period witnessed profound political, social, and economic transformations, driven by revolutionary ideas and technological advancements:
* Enlightenment ideals of liberty, equality, and human rights fueled revolutions in America and France, challenging traditional forms of authority.
* The Industrial Revolution bought technological innovations, such as the steam engine and the power loom, led to mass production, urbanization, and significant social changes.
* The rise of nationalism and imperialism led to the formation of new nations, while European powers expanded their colonial empires across the globe.

=== The 20th and 21st Centuries ===

This era has been marked by rapid technological advancements, globalization, and significant social and political changes:
* Two world wars and numerous other conflicts reshaped the global political landscape and led to the formation of international organizations like the United Nations.
* Rapid advancements in transportation, communication, and information technology have led to increased global interconnectedness and transformed human life.
* Globalization and and the flow of goods, ideas, and people across borders has led to increased cultural exchange and the emergence of a global culture.
* Social and political movementsfor civil rights, women's rights, and environmental protection have challenged social norms and led to significant social and political changes.

== Minds ==

What is consciousness? How do we understand and interact with the world

== The Future ==

Is a future of progress assured? Will AI help or destroy us? Are we slowly being ushered into a matrix-like state?

Books

2025-04-20T16:51:49Z

Rob: /* 2025 */

== Books to Buy ==

* Language, Thought, and other Biological Categories
* The Flat Mind
* On the Calculation of Volume - Solvej Balle
* Open Socrates - Agnes Callard
* Why Machines Learn: The Elegant Maths Behind Modern AI (out in paperback Jan 30 2025)
* A History of the Muslim World: From Its Origins to the Dawn of Modernity (awaiting paperback)
* How Life Works: A User’s Guide to the New Biology
* Stranger Than Fiction: Lives of the Twentieth-Century Novel
* Grey Matters: A Biography of Brain Surgery - not yet in paperback
* The New Roman Empire: A History of Byzantium
* Magnetic Mountain: Stalinism as Civilization
* Consolations - David Whyte

== Books to Read ==

* Reading to Learn - William Zinger
* Breakfast of Champions - Kurt Vonnegut
* A Little History of Philosophy - Nigel Warburton

== Currently Reading ==

* [[Atomic Habits]] - James Clear
* [[Das Ludwig Thoma Komplott]]- Sabine Vöhringer

== Books Read ==

=== 2025 (week 17) ===

* [[Why We Remember: Revealing the Hidden Power of Memory]] - Dr Charan Ranganath
* [[From Bacteria to Bach and Back]] - Daniel Dennett (re-read)
* [[The Village of Eight Graves]] - Seishi Yokomizo
* [[Science: A History]] - Richard Crockett
* [[Vienna: How the City of Ideas Created the Modern World]] - John Gribbin
* [[The Inugami Curse]] - Seishi Yokomizo
* [[The Rise and Reign of the Mammals]]
* [[Four Ways of Thinking]] - David Sumpter
* [[I've Been Thinking]] - Daniel Dennett
* [[Serendipities: Language and Lunacy]] - Umberto Eco
* [[I Am Dynamite: A Life of Friedrich Nietzsche]] - Sue Prideaux
* [[A Brief History of Intelligence]] - Max S. Bennett
* [[Foucault’s Pendulum]] - Umberto Eco (re-read)
* [[Kant and the Platypus]] - Umberto Eco
* [[Le cerveau m’a beaucoup déçu. L’esprit, non]] - Antoine Sénanque

=== 2024 ===

* The Plot - Will Eisner
* The Prague Cemetery - Umberto Eco
* The Nonjin Murders - Seishi Yokomizo
* When We Cease to Understand the World - Labatut
* Zen and the Art of Motorcycle Maintenance - Robert Pirsig (reread)
* The Way We Think: Conceptual Blending and the Mind’s Hidden Complexities - Fauconnier and Turner
* The Singularity is Nearer - Ray Kurzweil
* Physics and Philosophy - Werner Heisenberg
* Le Ton Beau de…
* The Origins of Creativity - Edward O Wilson
* Psychonauts -
* The MANIAC - Benjamin Labatut
* In Search of Memory - Eric R. Kandel
* Dreaming: A Very Short Introduction - Hobson
* Les Effinger - Gabriele Target
* Triad - Tom Keve
* Nietzsche - Stefan Zweig
* The Weirdest People in the World - Joseph Henrich
* How Language Works - David Crystal
* The Invention of Nature - Andrea Wolf
* The Song of the Cell - Siddhartha Mukherjee
* [[Gödel, Escher, Bach]] - Douglas Hofstadter
* [[From Bacteria to Bach and Back]] - Daniel Dennett

[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-20T16:50:08Z

Rob: /* When We Remember Together */

== Where is My Mind? - The Neocortex ==

* By one estimate, the average American is exposed to 34GB (or 11.8hr) of information a day
* Hermann Ebbinghaus “On Memory: A contribution to Experimental Psychology (1885) - tried to memorize trigrams, established the idea of a forgetting curve over time.
* In essence, neurons function like a democracy with alliances or “cell assemblies”.
* Somewhere is the brain’s speech centers a large coalition of neurons cases votes for “bath”, a smaller coalition votes for “path”, and an even smaller minority votes for other candidates. Within less than half a second, the vote is tallied, and ultimately the baby picks up that it is time for a bath. The connections between the neutaons that supported bath are strengthened, and connections with neurons that voted for the wrong sound are weakened. As those neurons settle into coalitions that differentiate between the sound the baby is hearing, they are becoming less sensitive to sound differences that don’t exist in that language. It’s as if the neurons are choosing between a small number of candidates based on a few key issues.
* The connections in your brain are constantly being reshaped with the goal of improving your perception, movement, and thinking as you gain more and more experiences. Moreover, as you go past simple perception (what we see, hear, touch, taste, and smell) and move into higher-order functions (eg judgement, evaluation, and problem-solving), the brain is remarkably plastic, and the neural elections are highly contested.
* Interference - there is an intense competition between the coalition that has the memory you’re looking for and coalitions representing other memories you don’t need at that moment.
* The memories that are the most distinctive are the easiest to remember because they stand out relative to everything else.
* Attention - is our brain’s way of prioritizing what we are seeing, hearing, and thinking about.
* Intention - guide’s your attention to lock on to something specific.
* The prefrontal cortex:
** I the “central executive” of the brain. Several regions all over the brain have relatively specialized functions, and the job of the prefrontal cortex is to serve as a central executive, coordinating activity across these networks in the service of the mutual aim.
** Helps us learn with attention
** Takes up about a third of the real estate in the human brain
** Frontal lobotomy - removal of the prefrontal cortex - but rather than treating any underlying mental illness, it leaves patients in a zombielike state, apathetic, docile, and devoid of motivation.
** The more numbers people had to keep in mind, the more activity was apparent in the prefrontal cortex - it plays a part in temporarily holding information.
** People without a functioning prefrontal cortex could do fine when they were given clear instructions and no distractions, but they struggled when they had to spontaneously use memory strategies or follow through on a task when irrelevant things competed for their attention.
** Is intensively activated when a person had to use intention to stay on task, focus on distinctive information, resist distractions, or initiate some kind of mnemonic strategy.
** ADHD is associated with atypical activity in the prefrontal cortex.
** As we get older, we can still learn, but we have more trouble focusing on the details we want to take in and we often end up learning things that might be irrelevant.
** Certain part of the prefrontal cortex are thinned out, on average, in people who do heavy media multitasking.
* Use intention to guide our attention so we can remember what matters. Balance the needs of the experiencing self and the remembering self.

== Travelers of Time and Space - The Hippocampus ==
* We often think about memory as a record of what happened, but the human brain has the remarkable capability to link up the “what” with the where, when, and how. This explains why the experience of remembering is so often accompanied by an ephemeral sense of pastness that’s almost impossible to put into words. It’s also why, if we are in the right place at the right time, lost memories seem to find us.
* That sense of being in a particular time and place is called context, and it is critical for our day-to-day memory experiences. A great deal of everyday forgetting happens not because our memories have disappeared but because we can’t find our way back to them. In the right context, however, memories that have seemed long gone can suddenly resurface back to the forefront of our recall.
* Endel Tulving, in 1972, coined the term “episodic memory” to differentiate from “semantic memory”. To remember an event (episodic memory), we need to mentally return to a specific place and time; but to have knowledge (semantic memory), we need to be able to use what we previously learned across a range of contexts.
* For Tulving remembering puts us in a state of consciousness in which we feel as if we were transported to the past. A key characteristic of human consciousness is that we are “capable of mental time travel, roaming at will over what has happened as readily as over what might happen, independently of the physical laws that govern the universe.”
* You can confidently pull up facts about Paris (semantic memory) and vividly reexperience a trip to Paris (episodic memory), yet the two experiences are totally different.
* AIs have problems with “catastrophic forgetting”, where they learn a rule and then an exception to the rule makes them then throw away everything they had learnt around that rule to date. But we have episodic memory, which is not designed to capture the common elements of all our experiences; it stores and indexes every event differently, so you don’t get mixed up when you learn the exception to the rule.
* The neocortex works like a traditional neural network, enabling us to pick up facts, while the hippocampus is responsible for the brain’s amazing ability to rapidly create new memories for events.
* Brenda Milner, in 1957, published a paper about Patient H.M., Henry Molaison who had his seizures treated by removing about 5cm of tissue from the left and right hippocampus. Milner’s paper definitively linked the formation of new memories to the hippocampus.
* Ranganath suggested that the pattern of light and dark pixels identified by fMRI might be a unique configuration acting as a pointer to a particular memory like a QR code. When thinking about two separate episodic memories about the same person, the neocortex seemed to store the general facts about who and what were in the event, while in the hippocampus, the memory codes for the two related events looked totally different.
* The cell assemblies that allow us to remember particular parts of an event are in separate areas of the brain that normally do not talk to one another. The only thing they have in common is that they were active around the same time. The hippocampus, however, has connections to many of these areas, and its job is to store links to the different cell assemblies that come to life at a given moment. If you revisit the place, then the hippocampus would help reactivate all those cell assemblies, enabling you to reexperience seeing your friend. The hippocampus enables us to “index” memories for different events according to when and where they happened, not according to what happened. Because it organizes memories according to the context, recalling something from one event makes it easier to retrieve other events that happened around the same time or place, painting a fuller picture.
* Pulling up a memory of the recent past helps to ground you in the here and now. According to one prominent theory, episodic memory emerged in evolution from the more basic ability to learn where we are in the world.
* Sea lions without a functioning hippocampus grow disoriented. Lost, and unable to recall their foraging sites, they become malnourished and ultimately stranded onshore.
* The hippocampus is one of the first areas of the brain ravaged by Alzheimer’s, and this is probably why patients in the early stages frequently get lost and lost track of the passage of time. You see the look of fear on a face when a patient becomes unmoored from their sense of when and where they are in the world, like treading water in the open ocean.
* All the external factors from our environment, along with the motivations, thoughts, and feelings that characterize our internal world, come together to form the unique context that envelops our experience at any given time. When we access a particular episodic memory, we can pull up a bit of that past mental state, too.
* Two events that occurred close together in time are going to have more contextual elements in common than events that occurred further apart in time.
* Place, smells, tastes, and music are all powerful cues for episodic memories.
* Our emotions also contribute to context, which means that our feelings in the present affect what we can recall from the past. When we get angry, it’s easy to pull up all those memories that give us more reasons to be annoyed, and it’s harder to access the memories that don’t.
* The essential trick performed by the hippocampus is that it takes in information about the things in which we are interested, and it ties it up with information about the context, all the other stuff that’s going on in the background. We experience zillions of repetitive events, but the context makes each unique, and we can use context as a lifeline to find our way back to those things we seem to always lose.
* The further back in time you try to go, the harder it is for your brain to pull up a past context, and in some cases you won’t be able to do it. Science backs infantile amnesia where you can’t have episode memories before the age of two because the hippocampus is still developing and the entire neocortex is being massively reorganized.
* Event boundaries. We naturally update our sense of context when we experience a shift in our perception of the world around us, and those points mark the boundary between one event and another. People are better at remembering information that occurred at an event boundary then they are at remembering information from the middle of the event, and this is because the hippocampus waits to store a memory for an event until right after an event boundary - so we only encode the memory once we have a full understanding of the event.
** Event boundaries happen all the time and don’t necessarily require a change in location. Anything that alters your sense of the current context - a shift in the topic of conversation, a change in your immediate goals, or the onset of something surprising - can lead you to put up an event boundary.
* During the Covid epidemic, confined to home and with few event boundaries to provide meaningful structure to their lives, millions of people all over the world felt as if they were living in the twilight zone, floating aimlessly through time and space.
* Nostalgia - on average, people find it easier to recall positive experiences than negative ones, and this positivity bias increases as we get older, which might explain older adults’ penchant for nostalgia.
** The reminiscence bump - when we look back at the past, we tend to focus on a specific period of our lives, between the ages of ten and thirty - something about listing to a song or watching a movie from those formative years can give us a sense of meaning, connecting us to an idealized sense of who we are.
** The cost of nostalgia is that it can leave us feeling disconnected from our lives in the present, giving us a sense that things aren’t as they were in the “good old days”.
* Rumination - is the evil twin of nostalgia, and a prime example of how not to use episodic memory.

== Reduce, Reuse, Recycle - Schemas and the Default Mode Network (DMN) ==
* We can keep up to only 3-4 pieces of information in mind at once, but there is a huge loophole: there is no set definition for what constitutes one piece of information. Chunking allows us to compress massive amounts of data into a manageable amount of information that is easily accessible.
* Like memory athletes, chess grand masters use a combination of skill, training, and experience - aka expertise - to chunk at lightning speed. Expertise changes the way we mobilize the prefrontal cortex. Experts develop particular ways to extract the most useful information about what they are trying to remember, allowing them to bypass the limitations of memory by leveraging their expertise.
* Expertise isn't just about seeing patterns, it's about the way we find them. As we gain expertise in any topic, we can exploit what we have learned to focus on the most important bits of new information that we need.
* The human brain is not a memorization machine; it's a thinking machine.
* A schema is a kind of mental framework that allows our minds to process, organize, and interpret a great deal of information with minimal effort. A schema is like a blueprint for a space or an event. Event schemas provide the structure that allows us to rapidly form memories for a complex event. They are like scripts for ordering coffee, meeting a colleague, going to the cinema, etc.
* In some way or another, every expert exploits the power of schemas to organize what they need to remember into a framework they can access later.
* The Default Mode Network (DMN) is a set of neocortical areas that consume the most energy in the brain, yet activity in these areas seems to go down when people are focusing their attention on some arbitrary task. Brain activity in the hippocampus is tightly linked with what is going on in the DMN. It seems that cell assemblies in the DMN store the schemas we use to understand the world, dissecting the events we experience into pieces so that we can use them in new ways to construct new memories. The hippocampus could, in turn, put the pieces together to store a specific episodic memory.
* In an experiment about watching and recounting the plots of movies:
** The DMN was providing the raw materials needed to understand and remember each movie, but it was not storing context-specific episodic memories. Instead of storing a unique memory code for each movie, the DMN was breaking up each movie into components that were repeatedly reused to understand or remember other movies that shared the same components. Memory codes in one part of the DMN could tell us whether the subject was watching or remembering a movie that took place in a supermarket or a café, whereas memory codes in a different part of the DMN could tell us whether A or B was the star in the movie.
** In contrast to the DMN, the hippocampus, which supports episodic memory by putting together information from all over the brain - did have a separate memory code for each movie. And unlike the DMN, the hippocampus only seemed to store a memory for the beginning and end of each movie (ie, the event boundaries).
** Thanks to the DMN, I can reuse my supermarket schema every time I shop for groceries, and I can reuse my A schema every time I see A. And thanks to the hippocampus, I can also form different memories for every specific occasion that I run into A at the supermarket.
* Forming an episodic memory is a bit like building with LEGOs, breaking down models and using the independent components again and again in different contexts.
* It's now clear that amyloid - a protein implicated in the development of Alzheimer's disease - accumulates in the DMN in about 20% of older adults long before any symptoms are apparent.
* A chess grand master has a library of chess game schemas, each containing templates for entire sequences of moves you typically see in a game. Those schemas allow them to remember sequences of moves in past games, to understand what is happening in a game in real time, and to predict likely moves that an opponent could make in the future. By exploiting that expert knowledge, a seemingly complex configuration of pieces can easily be understood as one step in a series of moves that might wipe out a number of pieces and lead to a checkmate.
* Schemas allow us to see through an event, capturing the deeper structures of how everything is connected. In doing so, we can compress memories of hundreds, even thousands, of experiences into a format that enables us to make inferences and predictions about events we haven't yet experienced. Schemas allow us to use knowledge about what has happened to get a head start on what will happen.

== Just My Imagination ==
* Shereshevsky - the capacity of his memory had no distinct limits.
* He may have had synesthesia - every stimulus, regardless of which sense it came through, triggered every other sense. He could taste words, see music and smell colors.
* The connection between the worlds he created in his mind and the world he lived in was so visceral that he could elevate his hear rate by simply imagining he was running for a train. He could raise the temperature of one hand and lower the other by picturing one hand on a stove and the other resting on a block of ice.
* The brain activity changes that occur when people imagine these kinds of scenarios are remarkably similar to those that occur when people recall events that they actually experienced.
* "Remembering is not the re-excitation of innumerable fixed, lifeless and fragmentary traces. It is an imaginative reconstruction." We do not simply replay a past event, but use a small amount of context and retrieved information as a starting point to imagine how the past could have been. We put together a story on the fly, based on our personal and cultural experiences, and tack on those retrieved details to flesh out the story. Bartlett's insight is key to understanding why the brain's machinery for imagination and for memory aren't completely independent - they are both based on pulling up knowledge about what can happen, though not necessarily what did happen.
* The hippocampus might get us back to some of the cell assemblies that were active during some moments in a conversation, but we still need to use schemas in the default network to make sense of what we are pulling up. this reconstruction is prone to error, however, because schemas capture what typically happens, not what did happen.
* Our minds are constantly churning with what-ifs. We conjure up scenarios for what could happen in the future, and we wonder what our present would be like if past events had turned out differently. All the scenarios we imagine leave us with memories of events we have never experienced, and our memories don't come with labels certifying them as imagined or real.
* So we need reality monitoring. The more sensory details that come to mind when you remember an event, the more likely it is that it really happened, because on average what we imagine is not as detailed as what we have experienced.
* We can counteract the fallibility of memory by considering not only the quality of the details that seem to put us back in a specific place and time but also the likelihood that those details could have been constructed to create an alternative reality. As with all critical thinking, it helps to remain skeptical until presented with further evidence.
* Monitoring the details of our memories engages the most evolutionarily advanced areas of the human prefrontal cortex.
* Confabulation: Some people who have extensive damage to the prefrontal cortex can confidently recall things that never happened. We all are guilty of minor confabulations. When we're tired or stressed out, or when our attention is divided by multitasking, reality monitoring goes out the window. As we get older, prefrontal function gets words, and we find it harder to tell the difference between imagination and experience.
* In 1928, Bartlett speculated that creative works are constructed by essentially doing the opposite of reality monitoring - that is, by pulling up fragments of memories and then assembling those bits and pieces into a cohesive product of imagination.
* The hippocampus and the DMN might function at the crossroads between memory and imagination by allowing us to extract the ingredients from past experiences and recombine them into new creations.
* AI art is not about generating something new, it's about taking elements from preexisting human art and recombining them (based on human direction and curation).
* We now know that it is in that space where memory meets imagination that we interpret reality and create our greatest treasures.

== More Than a Feeling - the Amygdala ==
* Our emotions, as well as the actions and choices they influence, are shaped by basic survival circuits in the brain that motivate us to avoid threats, find sustenance, and reproduce. When these circuits go into overdrive, we tend to experience intense emotions, such as elation, lust, panic, anxiety, or disgust. These are experiences we remember most vividly, because they provide valuable information that we can use in the future to stay safe, thrive, and reproduce.
* Neuromodulators promote plasticity, enabling long-lasting changes in the connections between neurons in the cell assemblies that are activated when we learn something new.
* Noradrenaline (AKA norepinephrine) is released all over the brain in response to threats. Emotional arousal changes what we will remember, rather than simply how much. If you get mugged your attention will be on the weapon pointed at you rather than the mugger's shoes. It's easy to forget more mundane experiences, but hard to let go of a traumatic memory: our brains are designed to hold on to the events that revved us up, ostensibly because remembering those events has survival value.
* When we recall a time our survival circuits were called into action, the hippocampus works with the amygdala. As the hippocampus forms memories that capture the context at that moment, the amygdala is connecting those memories with the survival circuits that generate the raw sensations. Later on, when remembering, the amygdala brings us back to the heat of the moment, making us feel as if we are vividly reexperiencing the event.
* We feel anxious when we think something bad might happen, but we cannot predict or control whether it will happen.
* Cortisol spikes when you are stressed out to improve your ability to retain memories for what happened right before or after the stressful event. Like noradrenaline, stress hormones seem to promote plasticity, initiating the cascade of changes that consolidate connections within the cell assemblies representing the memory for a stressful event.
* Stress tips the chemical balance in the brain, downregulating the executive functions mediated by the prefrontal cortex and enhancing the sensitivity of the amygdala.
* In the healthy brain, if the hippocampus does its job, then memories for traumatic events should be associated with a specific context. Hippocampal dysfunction in experimentally stressed lab animals, and in humans with PTSD may cause traumatic memories to become overgeneralized.
* Dopamine is central to helping us form lasting memories for rewarding experiences. Like other neuromodulators, dopamine promotes plasticity, and its release tends to be concentrated in several brain areas that are important for helping us learn how to get rewards:
** Dopamine in the amygdala helps us learn about cues that signal an upcoming reward.
** In the hippocampus, it helps us learn about the contexts where we are likely to get rewards.
** in the nucleus accumbens, it helpus us learn what we need to do to get the reward.
* Over all, dopamine associates cues, contexts, and actions that lead to rewards and sets expectations that shape our experience when we get them.
* We are wired to learn only when the outcomes don't match up with our expectations.
* Sudden drops in dopamine activity drain motivation, while an increase in dopamine activity can be energizing.
* We often feel intensely motivated to seek out a reward even when we know it won't necessarily be pleasurable - cheating on a diet, smoking a cigarette when we have quit - this is the result of dopamine driving us.
* In gambling studies, when people unexpectedly won a bet, we saw a large neural response, but when they expected to win and did, we saw only a small neural response. if a person had a large neural response after seeing the outcome of the bet, they would be more likely to make the same bet next. The people who favored risky bets showed more activity in reward-learning circuits when they won than people who tended to play it safe. And unlike risk-averse subjects, risk-takers still got a bump of activity in the reward circuit even when they lost a risky bet. At least some people might have a reward-learning circuit that leads them to persist in making risky decisions even after bad outcomes.
* Cocaine, meth, heroin, opioids, and alcohol all activate the dopamine system, and can lead to powerful addictions.

== All Around Me Are Familiar Faces ==
* We tend to be more interested in exploring things that are new to us, than in things we have seen before.
* Electrical signals in the perirhinal cortex can artificially produce a sense of intense familiarity or novelty. This suggests that it might be responsible for that sense of familiarity we naturally experience when we visit a place or see a person we have seen before.
* The more activity in the perirhinal cortex when our volunteers read a word in the MRI scanner, the more familiar that word would seem when they saw it again on the surprise test. And, unlike with the hippocampus, activity in the perirhinal cortex was not related to people's ability to recollect the context of words that they had studied. Memories are not just strong of weak; rather the human brain has two different kinds of memory:
** Episodic memory, which is supported by the hippocampus
** Familiarity, which is supported by the perirhinal cortex.
* Cell assemblies all over the brain are in constant flux, reorganizing and optimizing so that the neural elections that determine our perceptions, thoughts, and actions will come to swift and decisive conclusions. When those tweaks happen in sensory areas, they help us read, see, and experience the world more efficiently. Those little tweaks also happen in higher-level areas of the brains, such as the perirhinal cortex, that integrate information from our different senses to help build semantic memories.
* All this neural plasticity seems to happen without our awareness, but the outcome can be sensed. the more familiar we become with something, the more our cell assemblies become fine-tune to recognize that thing later on. So, if we pay attention to how much mental effort we put in to read a word or recognize a face, we can get a sense of how much experience we have with it.
* When you initially think about a concept, such as a rambutan, activity spikes in the perirhinal cortex. It's as if this area of the brain is trying to match the word to a template you haven't yet created. In the aftermath of that encounter, the neural coalitions in this area get reorganized. The next time you think about rambutans, there's less activity because the election is resolved faster. The tweaking that happens after repeatedly seeing that word improves the brain's efficiency, reducing brain activity in the perirhinal cortex and making it easier to access the concept of rambutans.
* We often (mis)use familiarity as a heuristic, or mental shortcut, to guide decisions. Moreover, we can be blissfully unaware of these influences and instead reinforce our sense of free will by constructing stories that assign meaning to our choices and actions.
* Experience doesn't just change what you see, it changes what you look for. People tend to pay attention to the features that best distinguish faces of people from their own race, at the expense of features that help us recognize faces from other races.
* Like every other aspect of memory, familiarity has both a good and a bad side. It can be a useful by-product of how the brain is constantly becoming more efficient in its perceptions, but its slippery nature means that the fluency that results from mere exposure to something can operate under the radar of awareness, influencing our choices, judgments, and behavior. When we go on autopilot, familiarity can constrain our options and leave us with a smaller world.

== Turn and Face the Strange ==
* Memory's most important feature - orienting us to the future.
* Our memories of the past - "the old" - enable us to allocate critical resources to what is new and what has changed.
* Prediction errors initiate a cycle in the brain in which memory orients us to the unexpected, stimulating curiosity and motivating us to explore and resolve the gaps between our predictions and what we face in the present.
* Our eyes move about 4 times a second.
* When entering a space, we have:
** General knowledge (semantic memory) of what is supposed to be in a particular place.
** Familiarity - our eyes don't linger on things that are familiar, because we don't need to work as hard to process information about familiar objects, faces, or places.
* A major evolutionary function of the hippocampus is to tall us about places that are new or different, so we can explore and learn about these aread.
* Seeing something new or out of place should trigger a signal from the hippocampus stimulating us to explore out surroundings.
* Activity in the hippocampus increased when the subjects looked at pictures of new places.
* The brain's response to what is new is tightly coupled to our ability to remember what we have previously encountered, and that a loss of this novelty response may be an early indicator of risk for Alzheimer's disease.
* The hippocampus is critical for attuning our attention to changes in our environment.
* We might rely on these hippocampal memories to guide what to expect in the here and now. If something isn't in the right place, your spider-sense goes off, and your brain sends a signal to your eyes to scan that area so you can figure out what happened.
* Seeing the place was enough to trigger retrieval of a memory from the hippocampus.
* The hippocampus is one of the most evolutionary ancient structures in the brain.
* The orienting response, is an orchestration of changes in the brain and the body in response to something new or surprising. Our pupils enlarge, increasing sensitivity to light. Blood is pumped to the brain and constricted in the rest of the body, and the brain gets a brief shot of neuromodulators, such as dopamine, noradrenaline, and acetylcholine. There's also a coordinated changes in neural activity throughout a network of brain areas, including the hippocampus and the prefrontal cortex.
* The orienting response is probably one of the most reliable indicators of a functioning hippocampus.
* The hippocampus is like a "What is it?" detector, alerting the brain to something unexpected. It preferentially forms memories for the oddball images.
* Activity in the accumbens spiked about half a second after they saw the oddball image and the findings suggested that surprising or unexpected events can be sufficient to trigger activity in this system even when we do not get an external reward.
* Curiosity is triggered when we discover a discrepancy between what we know and what we'd like to know, a nebulous space "the information gap". Loewenstein proposed that curiosity is about the motivation to seek information, rather than the satisfaction of getting our questions answered. This drive is evolutionarily adaptive because it helps us maintain a balance between exploration (of the new) and exploitation (of the existing).
* By tapping into the reward circuitry, curiosity can enhance memory. This circuitry isn't about rewards, per se; it's about mobilizing us to learn and pursue anything we perceive to have value. And after food, water, and other basic needs are met, this means information.
* People have tendencies, conscious, or unconscious, about whether to respond to the unknown with curiosity or anxiety.

== Press Play and Record ==
* The catalyst for memory updating is the very act of remembering.
* Every time we recall an experience is one link in a neural chain subject to edits and updates, so that, over time, our memories can drift further and further from that initial event.
* We are especially vulnerable to misinformation at the moment of remembering.
* When we revisit a memory over and over, subtle alterations can creep in with each repetition. It's a bit like making a copy of a copy of a copy; the neural connections that hold together a memory are tweaked, and these changes can enlarge some aspects of the experience, while causing us to lose some of the details that keep the memory in focus. Like the fuzzy letters on my college band flyers, events from the distant past can seem more remote and blurry every time we call upon them, and noise becomes more prominent, corrupting the memory a bit more each time it's recalled.
* They made a painstakingly detailed computer model of hippocampus!
* Implanted memories, such as being lost in a mall are not entirely false; rather they are most likely imaginative constructions that incorporate information from schemas and details from real experiences.
* Memory is malleable, but it isn't mush.
* The sequence of steps in consolidation seems to happen whenever we retrieve a memory.
* We already know that memories can be strengthened, weakened, or modified from the moment they are pulled up. This kind of memory updating is at the heart of psychotherapy, which is fundamentally about changing connections that we made in the past in the face of new information. The goal isn't to erase someone's memories of what happened but to adaptively update memories and change one's relationship with the past by approaching it from a different perspective.

== Some Pain, More Gain ==
* Error-driven learning is how we learn to make skilled movements by observing the difference between what we intend to do and what we actually do.
* The benefits of testing do not come from making mistakes per se, but rather from challenging yourself to pull up what you have learned. To understand why, let's go back to our cell assemblies analogy. When you test yourself, your brain will try to generate the right answer, but the result isn't quite perfect.
* Stress testing your memory like this exposes the weaknesses in the cell assemblies so that the memory can be updated, strengthening the useful connections and pruning the one that are gettin in the way. Rather than relearning the same thing over and over, it's much more efficient to tune up the right neural connections and fix just those parts that we are struggling with. Memory updating is the key, because the most efficient way for our brains to save space and learn quickly is to focus on what we didn't already know.
* Memory is not a collection of isolated islands; it's an ecosystem of interacting cell assemblies.
* Retrieval-induced forgetting - When recalling one memory can make it harder to pull up related memories.
* Retrieval-induced facilitation - When people were tested on one of the facts in an article, the benefits of that test spilled over to related facts.
* The shared episodic memory means that an alliance is built between the cell assemblies that back the different components of the lasagna dinner, and when we recall the lasagna, error-driven learning tightens up the alliance, pulling up other connected elements from the same event.
* The spacing effect - if you keep returning to the same information periodically, the hippocampus can continually update those memories until they have no discernible context, making it easier to access them in any place at any time.
* During sleep, the brain goes back and forth between at least five different states. Slow-wave sleep (SWS) and rapid eye movement (REM sleep work hand-in-hand to transform our recent experiences into knowledge that we can use:
** SWS is the deepest sleep stage - there is a fully orchestrated interaction between the hippocampus and the neocortex during SWS. Large, slowly traveling electrical waves cycle across the neocortex, with smaller waves of activity called spindles riding atop the crest. Meanwhile in the hippocampus, little bursts of activity called ripples bubble up, and during each ripple, individual neurons in the hippocampus that were active during the daytime come back to life, firing off in little sequences. Ripples, in turn, trigger bursts of activity in the default mode network (DMN), which helps us use schemas to learn about new events, and in the prefrontal cortex, which helps us intelligently use schemas to form memories for events and reconstruct them later on.
** REM is when dreams occur, and the dynamics of neocortical activity during REM might explain the vivid, lifelike experiences and bizarre logic that accompany our dreaming life. During REM sleep, the brain is generating its on sensory input and tries to make sense of it in the form of dreams, constructing an alternate reality all while you are in bed.
* Sleep may create an environment where cell assemblies active during different events play well together, rather than competing. When information from one event was reactivated in the model, the neocortex used this information to initiate a chain reaction of free associations. Information from different events was reconciled through error-driven learning, bringing out what was common across different events. The model suggest that when memories are reactivated during a test, error-driven learning helps to strengthen those specific memories, but when memories are reactivated during sleep, error-driven learning helps the brain to use threads of disparate experiences to weave a tapestry of knowledge.
* Sleep helps us integrate what we have recently learned across different events so we can use that information more efficiently. Memories for events sometimes become less context-dependent after sleep, and we are sometimes better at seeing big-picture relationships between small pieces of information that we had previously learned, and we are better able to use this information to solve problems.
* Sleep can allow us to convert memory into wisdom.
* The hippocampus helps us pull up specific patterns of brain activity that take us back to a particular place and time, whereas the neocortex stores the semantic knowledge that enables us to understand what happens in an event and make predictions and inferences in new situations. During SWS, the hippocampus can ignite cell assemblies that captured important experiences from the previous day (episodic memory), and then during REM, the neocortex can play around with this information, free-associating to discover possible connections between different events we've experienced.
* After a challenging bout of work, it can help to get a good night's sleep, take a nap, or at least take a little time to rest. During these down states, our brains can use error-driven learning to piece together elements from different experiences, potentially allowing us to see things from a different perspective, giving us leverage to tackle problems that previously seemed insurmountable.
* Targeted memory reactivation (inception) - the sleeping brain is highly receptive to the outside world.

== When We Remember Together ==
* The very act of sharing our past experiences can significantly change what we remember and the meaning we derive from it.
* We construct our sense of identity in part, through memories shared with our family and friends, as well as the memories shared across members from the same culture or nation. And our identities are built on ground that is constantly shifting, as we collaborate with one another to continually reconstruct and update our individual and collective memories.
* Children whose mothers asked open-ended questions and elaborated on their children's answers tend to remember more of their life experiences and put them together in a more coherent narrative than those whose mothers ask their children to recall specific information. These kinds of interactions can significantly impact a child's self-concept. Children who are encourage to have a voice develop more ownership over their sense of self because they are allowed to be authors of their personal narratives. Conversely, disallowing certain stories to be told or negating or disputing a child's perspective can undermine their sense of the experience and be detrimental to the development of the self.
* The process by which storytelling can change our view of the past can be seen as an extension of the principles that govern individual memory. When we remember, our reconstructions of the past are dominated by the beliefs and perspective we adopt in the moment, in this case while we share those memories with others. We tailor narratives for our audience, who can reinterpret our memories and reflect them back to us from a different perspective. As we interact with the audience to reconstruct our past experiences, memories can be updated in the process, allowing us to see our personal past from a different view.
* When people hear part of a story that can be stitched into a narrative with other story elements heard several minutes before, hippocampal activity increases and the memory code in the hippocampus is transformed.
* Collaborative inhibition - Surprisingly, those working in a group had worse memory performance.
* Collaborative facilitation - tends to happen when people have shared expertise that enables them to work as a team. The key to successful collaborative memory seems to lie in having some common ground, along with an appreciation for each other's distinctive contributions.
* What makes people susceptible to fake news? We have a bias to believe and therefore remember information that is consistent with our preexisting beliefs. Fake news is easier to digest if it comes in a flavor we already like. Consistent with research on social contagion, belief in fake news is also increased when the information is emotionally arousing, when it includes photoes as well as text, and when it comes from a source we know and trust.
* "Push-polls" designed not to collect opinions, but to spread misinformation. They seem to work by letting misinformation burrow into our memory
* Seeking out a fact check after consuming fake news can enable us to update our memories and thereby curtail the effects of misinformation.
* As we go about our lives, connections between neurons are constantly formed and modified, resulting in cell assemblies that help us sense, interact with, and understand the world around us. These intricately connected neural networks give us the ability to weave together the threads of the past so that we may envision how the future will unfold.
* Semantic memory, in particular, remains robust into old age.

[[Category:Consciousness]]
[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-20T16:19:05Z

Rob: /* Some Pain, More Gain */

Why We Remember: Revealing the Hidden Power of Memory

2025-04-20T15:29:35Z

Rob: /* Some Pain, More Gain */

== Where is My Mind? - The Neocortex ==

* By one estimate, the average American is exposed to 34GB (or 11.8hr) of information a day
* Hermann Ebbinghaus “On Memory: A contribution to Experimental Psychology (1885) - tried to memorize trigrams, established the idea of a forgetting curve over time.
* In essence, neurons function like a democracy with alliances or “cell assemblies”.
* Somewhere is the brain’s speech centers a large coalition of neurons cases votes for “bath”, a smaller coalition votes for “path”, and an even smaller minority votes for other candidates. Within less than half a second, the vote is tallied, and ultimately the baby picks up that it is time for a bath. The connections between the neutaons that supported bath are strengthened, and connections with neurons that voted for the wrong sound are weakened. As those neurons settle into coalitions that differentiate between the sound the baby is hearing, they are becoming less sensitive to sound differences that don’t exist in that language. It’s as if the neurons are choosing between a small number of candidates based on a few key issues.
* The connections in your brain are constantly being reshaped with the goal of improving your perception, movement, and thinking as you gain more and more experiences. Moreover, as you go past simple perception (what we see, hear, touch, taste, and smell) and move into higher-order functions (eg judgement, evaluation, and problem-solving), the brain is remarkably plastic, and the neural elections are highly contested.
* Interference - there is an intense competition between the coalition that has the memory you’re looking for and coalitions representing other memories you don’t need at that moment.
* The memories that are the most distinctive are the easiest to remember because they stand out relative to everything else.
* Attention - is our brain’s way of prioritizing what we are seeing, hearing, and thinking about.
* Intention - guide’s your attention to lock on to something specific.
* The prefrontal cortex:
** I the “central executive” of the brain. Several regions all over the brain have relatively specialized functions, and the job of the prefrontal cortex is to serve as a central executive, coordinating activity across these networks in the service of the mutual aim.
** Helps us learn with attention
** Takes up about a third of the real estate in the human brain
** Frontal lobotomy - removal of the prefrontal cortex - but rather than treating any underlying mental illness, it leaves patients in a zombielike state, apathetic, docile, and devoid of motivation.
** The more numbers people had to keep in mind, the more activity was apparent in the prefrontal cortex - it plays a part in temporarily holding information.
** People without a functioning prefrontal cortex could do fine when they were given clear instructions and no distractions, but they struggled when they had to spontaneously use memory strategies or follow through on a task when irrelevant things competed for their attention.
** Is intensively activated when a person had to use intention to stay on task, focus on distinctive information, resist distractions, or initiate some kind of mnemonic strategy.
** ADHD is associated with atypical activity in the prefrontal cortex.
** As we get older, we can still learn, but we have more trouble focusing on the details we want to take in and we often end up learning things that might be irrelevant.
** Certain part of the prefrontal cortex are thinned out, on average, in people who do heavy media multitasking.
* Use intention to guide our attention so we can remember what matters. Balance the needs of the experiencing self and the remembering self.

== Travelers of Time and Space - The Hippocampus ==
* We often think about memory as a record of what happened, but the human brain has the remarkable capability to link up the “what” with the where, when, and how. This explains why the experience of remembering is so often accompanied by an ephemeral sense of pastness that’s almost impossible to put into words. It’s also why, if we are in the right place at the right time, lost memories seem to find us.
* That sense of being in a particular time and place is called context, and it is critical for our day-to-day memory experiences. A great deal of everyday forgetting happens not because our memories have disappeared but because we can’t find our way back to them. In the right context, however, memories that have seemed long gone can suddenly resurface back to the forefront of our recall.
* Endel Tulving, in 1972, coined the term “episodic memory” to differentiate from “semantic memory”. To remember an event (episodic memory), we need to mentally return to a specific place and time; but to have knowledge (semantic memory), we need to be able to use what we previously learned across a range of contexts.
* For Tulving remembering puts us in a state of consciousness in which we feel as if we were transported to the past. A key characteristic of human consciousness is that we are “capable of mental time travel, roaming at will over what has happened as readily as over what might happen, independently of the physical laws that govern the universe.”
* You can confidently pull up facts about Paris (semantic memory) and vividly reexperience a trip to Paris (episodic memory), yet the two experiences are totally different.
* AIs have problems with “catastrophic forgetting”, where they learn a rule and then an exception to the rule makes them then throw away everything they had learnt around that rule to date. But we have episodic memory, which is not designed to capture the common elements of all our experiences; it stores and indexes every event differently, so you don’t get mixed up when you learn the exception to the rule.
* The neocortex works like a traditional neural network, enabling us to pick up facts, while the hippocampus is responsible for the brain’s amazing ability to rapidly create new memories for events.
* Brenda Milner, in 1957, published a paper about Patient H.M., Henry Molaison who had his seizures treated by removing about 5cm of tissue from the left and right hippocampus. Milner’s paper definitively linked the formation of new memories to the hippocampus.
* Ranganath suggested that the pattern of light and dark pixels identified by fMRI might be a unique configuration acting as a pointer to a particular memory like a QR code. When thinking about two separate episodic memories about the same person, the neocortex seemed to store the general facts about who and what were in the event, while in the hippocampus, the memory codes for the two related events looked totally different.
* The cell assemblies that allow us to remember particular parts of an event are in separate areas of the brain that normally do not talk to one another. The only thing they have in common is that they were active around the same time. The hippocampus, however, has connections to many of these areas, and its job is to store links to the different cell assemblies that come to life at a given moment. If you revisit the place, then the hippocampus would help reactivate all those cell assemblies, enabling you to reexperience seeing your friend. The hippocampus enables us to “index” memories for different events according to when and where they happened, not according to what happened. Because it organizes memories according to the context, recalling something from one event makes it easier to retrieve other events that happened around the same time or place, painting a fuller picture.
* Pulling up a memory of the recent past helps to ground you in the here and now. According to one prominent theory, episodic memory emerged in evolution from the more basic ability to learn where we are in the world.
* Sea lions without a functioning hippocampus grow disoriented. Lost, and unable to recall their foraging sites, they become malnourished and ultimately stranded onshore.
* The hippocampus is one of the first areas of the brain ravaged by Alzheimer’s, and this is probably why patients in the early stages frequently get lost and lost track of the passage of time. You see the look of fear on a face when a patient becomes unmoored from their sense of when and where they are in the world, like treading water in the open ocean.
* All the external factors from our environment, along with the motivations, thoughts, and feelings that characterize our internal world, come together to form the unique context that envelops our experience at any given time. When we access a particular episodic memory, we can pull up a bit of that past mental state, too.
* Two events that occurred close together in time are going to have more contextual elements in common than events that occurred further apart in time.
* Place, smells, tastes, and music are all powerful cues for episodic memories.
* Our emotions also contribute to context, which means that our feelings in the present affect what we can recall from the past. When we get angry, it’s easy to pull up all those memories that give us more reasons to be annoyed, and it’s harder to access the memories that don’t.
* The essential trick performed by the hippocampus is that it takes in information about the things in which we are interested, and it ties it up with information about the context, all the other stuff that’s going on in the background. We experience zillions of repetitive events, but the context makes each unique, and we can use context as a lifeline to find our way back to those things we seem to always lose.
* The further back in time you try to go, the harder it is for your brain to pull up a past context, and in some cases you won’t be able to do it. Science backs infantile amnesia where you can’t have episode memories before the age of two because the hippocampus is still developing and the entire neocortex is being massively reorganized.
* Event boundaries. We naturally update our sense of context when we experience a shift in our perception of the world around us, and those points mark the boundary between one event and another. People are better at remembering information that occurred at an event boundary then they are at remembering information from the middle of the event, and this is because the hippocampus waits to store a memory for an event until right after an event boundary - so we only encode the memory once we have a full understanding of the event.
** Event boundaries happen all the time and don’t necessarily require a change in location. Anything that alters your sense of the current context - a shift in the topic of conversation, a change in your immediate goals, or the onset of something surprising - can lead you to put up an event boundary.
* During the Covid epidemic, confined to home and with few event boundaries to provide meaningful structure to their lives, millions of people all over the world felt as if they were living in the twilight zone, floating aimlessly through time and space.
* Nostalgia - on average, people find it easier to recall positive experiences than negative ones, and this positivity bias increases as we get older, which might explain older adults’ penchant for nostalgia.
** The reminiscence bump - when we look back at the past, we tend to focus on a specific period of our lives, between the ages of ten and thirty - something about listing to a song or watching a movie from those formative years can give us a sense of meaning, connecting us to an idealized sense of who we are.
** The cost of nostalgia is that it can leave us feeling disconnected from our lives in the present, giving us a sense that things aren’t as they were in the “good old days”.
* Rumination - is the evil twin of nostalgia, and a prime example of how not to use episodic memory.

== Reduce, Reuse, Recycle - Schemas and the Default Mode Network (DMN) ==
* We can keep up to only 3-4 pieces of information in mind at once, but there is a huge loophole: there is no set definition for what constitutes one piece of information. Chunking allows us to compress massive amounts of data into a manageable amount of information that is easily accessible.
* Like memory athletes, chess grand masters use a combination of skill, training, and experience - aka expertise - to chunk at lightning speed. Expertise changes the way we mobilize the prefrontal cortex. Experts develop particular ways to extract the most useful information about what they are trying to remember, allowing them to bypass the limitations of memory by leveraging their expertise.
* Expertise isn't just about seeing patterns, it's about the way we find them. As we gain expertise in any topic, we can exploit what we have learned to focus on the most important bits of new information that we need.
* The human brain is not a memorization machine; it's a thinking machine.
* A schema is a kind of mental framework that allows our minds to process, organize, and interpret a great deal of information with minimal effort. A schema is like a blueprint for a space or an event. Event schemas provide the structure that allows us to rapidly form memories for a complex event. They are like scripts for ordering coffee, meeting a colleague, going to the cinema, etc.
* In some way or another, every expert exploits the power of schemas to organize what they need to remember into a framework they can access later.
* The Default Mode Network (DMN) is a set of neocortical areas that consume the most energy in the brain, yet activity in these areas seems to go down when people are focusing their attention on some arbitrary task. Brain activity in the hippocampus is tightly linked with what is going on in the DMN. It seems that cell assemblies in the DMN store the schemas we use to understand the world, dissecting the events we experience into pieces so that we can use them in new ways to construct new memories. The hippocampus could, in turn, put the pieces together to store a specific episodic memory.
* In an experiment about watching and recounting the plots of movies:
** The DMN was providing the raw materials needed to understand and remember each movie, but it was not storing context-specific episodic memories. Instead of storing a unique memory code for each movie, the DMN was breaking up each movie into components that were repeatedly reused to understand or remember other movies that shared the same components. Memory codes in one part of the DMN could tell us whether the subject was watching or remembering a movie that took place in a supermarket or a café, whereas memory codes in a different part of the DMN could tell us whether A or B was the star in the movie.
** In contrast to the DMN, the hippocampus, which supports episodic memory by putting together information from all over the brain - did have a separate memory code for each movie. And unlike the DMN, the hippocampus only seemed to store a memory for the beginning and end of each movie (ie, the event boundaries).
** Thanks to the DMN, I can reuse my supermarket schema every time I shop for groceries, and I can reuse my A schema every time I see A. And thanks to the hippocampus, I can also form different memories for every specific occasion that I run into A at the supermarket.
* Forming an episodic memory is a bit like building with LEGOs, breaking down models and using the independent components again and again in different contexts.
* It's now clear that amyloid - a protein implicated in the development of Alzheimer's disease - accumulates in the DMN in about 20% of older adults long before any symptoms are apparent.
* A chess grand master has a library of chess game schemas, each containing templates for entire sequences of moves you typically see in a game. Those schemas allow them to remember sequences of moves in past games, to understand what is happening in a game in real time, and to predict likely moves that an opponent could make in the future. By exploiting that expert knowledge, a seemingly complex configuration of pieces can easily be understood as one step in a series of moves that might wipe out a number of pieces and lead to a checkmate.
* Schemas allow us to see through an event, capturing the deeper structures of how everything is connected. In doing so, we can compress memories of hundreds, even thousands, of experiences into a format that enables us to make inferences and predictions about events we haven't yet experienced. Schemas allow us to use knowledge about what has happened to get a head start on what will happen.

== Just My Imagination ==
* Shereshevsky - the capacity of his memory had no distinct limits.
* He may have had synesthesia - every stimulus, regardless of which sense it came through, triggered every other sense. He could taste words, see music and smell colors.
* The connection between the worlds he created in his mind and the world he lived in was so visceral that he could elevate his hear rate by simply imagining he was running for a train. He could raise the temperature of one hand and lower the other by picturing one hand on a stove and the other resting on a block of ice.
* The brain activity changes that occur when people imagine these kinds of scenarios are remarkably similar to those that occur when people recall events that they actually experienced.
* "Remembering is not the re-excitation of innumerable fixed, lifeless and fragmentary traces. It is an imaginative reconstruction." We do not simply replay a past event, but use a small amount of context and retrieved information as a starting point to imagine how the past could have been. We put together a story on the fly, based on our personal and cultural experiences, and tack on those retrieved details to flesh out the story. Bartlett's insight is key to understanding why the brain's machinery for imagination and for memory aren't completely independent - they are both based on pulling up knowledge about what can happen, though not necessarily what did happen.
* The hippocampus might get us back to some of the cell assemblies that were active during some moments in a conversation, but we still need to use schemas in the default network to make sense of what we are pulling up. this reconstruction is prone to error, however, because schemas capture what typically happens, not what did happen.
* Our minds are constantly churning with what-ifs. We conjure up scenarios for what could happen in the future, and we wonder what our present would be like if past events had turned out differently. All the scenarios we imagine leave us with memories of events we have never experienced, and our memories don't come with labels certifying them as imagined or real.
* So we need reality monitoring. The more sensory details that come to mind when you remember an event, the more likely it is that it really happened, because on average what we imagine is not as detailed as what we have experienced.
* We can counteract the fallibility of memory by considering not only the quality of the details that seem to put us back in a specific place and time but also the likelihood that those details could have been constructed to create an alternative reality. As with all critical thinking, it helps to remain skeptical until presented with further evidence.
* Monitoring the details of our memories engages the most evolutionarily advanced areas of the human prefrontal cortex.
* Confabulation: Some people who have extensive damage to the prefrontal cortex can confidently recall things that never happened. We all are guilty of minor confabulations. When we're tired or stressed out, or when our attention is divided by multitasking, reality monitoring goes out the window. As we get older, prefrontal function gets words, and we find it harder to tell the difference between imagination and experience.
* In 1928, Bartlett speculated that creative works are constructed by essentially doing the opposite of reality monitoring - that is, by pulling up fragments of memories and then assembling those bits and pieces into a cohesive product of imagination.
* The hippocampus and the DMN might function at the crossroads between memory and imagination by allowing us to extract the ingredients from past experiences and recombine them into new creations.
* AI art is not about generating something new, it's about taking elements from preexisting human art and recombining them (based on human direction and curation).
* We now know that it is in that space where memory meets imagination that we interpret reality and create our greatest treasures.

== More Than a Feeling - the Amygdala ==
* Our emotions, as well as the actions and choices they influence, are shaped by basic survival circuits in the brain that motivate us to avoid threats, find sustenance, and reproduce. When these circuits go into overdrive, we tend to experience intense emotions, such as elation, lust, panic, anxiety, or disgust. These are experiences we remember most vividly, because they provide valuable information that we can use in the future to stay safe, thrive, and reproduce.
* Neuromodulators promote plasticity, enabling long-lasting changes in the connections between neurons in the cell assemblies that are activated when we learn something new.
* Noradrenaline (AKA norepinephrine) is released all over the brain in response to threats. Emotional arousal changes what we will remember, rather than simply how much. If you get mugged your attention will be on the weapon pointed at you rather than the mugger's shoes. It's easy to forget more mundane experiences, but hard to let go of a traumatic memory: our brains are designed to hold on to the events that revved us up, ostensibly because remembering those events has survival value.
* When we recall a time our survival circuits were called into action, the hippocampus works with the amygdala. As the hippocampus forms memories that capture the context at that moment, the amygdala is connecting those memories with the survival circuits that generate the raw sensations. Later on, when remembering, the amygdala brings us back to the heat of the moment, making us feel as if we are vividly reexperiencing the event.
* We feel anxious when we think something bad might happen, but we cannot predict or control whether it will happen.
* Cortisol spikes when you are stressed out to improve your ability to retain memories for what happened right before or after the stressful event. Like noradrenaline, stress hormones seem to promote plasticity, initiating the cascade of changes that consolidate connections within the cell assemblies representing the memory for a stressful event.
* Stress tips the chemical balance in the brain, downregulating the executive functions mediated by the prefrontal cortex and enhancing the sensitivity of the amygdala.
* In the healthy brain, if the hippocampus does its job, then memories for traumatic events should be associated with a specific context. Hippocampal dysfunction in experimentally stressed lab animals, and in humans with PTSD may cause traumatic memories to become overgeneralized.
* Dopamine is central to helping us form lasting memories for rewarding experiences. Like other neuromodulators, dopamine promotes plasticity, and its release tends to be concentrated in several brain areas that are important for helping us learn how to get rewards:
** Dopamine in the amygdala helps us learn about cues that signal an upcoming reward.
** In the hippocampus, it helps us learn about the contexts where we are likely to get rewards.
** in the nucleus accumbens, it helpus us learn what we need to do to get the reward.
* Over all, dopamine associates cues, contexts, and actions that lead to rewards and sets expectations that shape our experience when we get them.
* We are wired to learn only when the outcomes don't match up with our expectations.
* Sudden drops in dopamine activity drain motivation, while an increase in dopamine activity can be energizing.
* We often feel intensely motivated to seek out a reward even when we know it won't necessarily be pleasurable - cheating on a diet, smoking a cigarette when we have quit - this is the result of dopamine driving us.
* In gambling studies, when people unexpectedly won a bet, we saw a large neural response, but when they expected to win and did, we saw only a small neural response. if a person had a large neural response after seeing the outcome of the bet, they would be more likely to make the same bet next. The people who favored risky bets showed more activity in reward-learning circuits when they won than people who tended to play it safe. And unlike risk-averse subjects, risk-takers still got a bump of activity in the reward circuit even when they lost a risky bet. At least some people might have a reward-learning circuit that leads them to persist in making risky decisions even after bad outcomes.
* Cocaine, meth, heroin, opioids, and alcohol all activate the dopamine system, and can lead to powerful addictions.

== All Around Me Are Familiar Faces ==
* We tend to be more interested in exploring things that are new to us, than in things we have seen before.
* Electrical signals in the perirhinal cortex can artificially produce a sense of intense familiarity or novelty. This suggests that it might be responsible for that sense of familiarity we naturally experience when we visit a place or see a person we have seen before.
* The more activity in the perirhinal cortex when our volunteers read a word in the MRI scanner, the more familiar that word would seem when they saw it again on the surprise test. And, unlike with the hippocampus, activity in the perirhinal cortex was not related to people's ability to recollect the context of words that they had studied. Memories are not just strong of weak; rather the human brain has two different kinds of memory:
** Episodic memory, which is supported by the hippocampus
** Familiarity, which is supported by the perirhinal cortex.
* Cell assemblies all over the brain are in constant flux, reorganizing and optimizing so that the neural elections that determine our perceptions, thoughts, and actions will come to swift and decisive conclusions. When those tweaks happen in sensory areas, they help us read, see, and experience the world more efficiently. Those little tweaks also happen in higher-level areas of the brains, such as the perirhinal cortex, that integrate information from our different senses to help build semantic memories.
* All this neural plasticity seems to happen without our awareness, but the outcome can be sensed. the more familiar we become with something, the more our cell assemblies become fine-tune to recognize that thing later on. So, if we pay attention to how much mental effort we put in to read a word or recognize a face, we can get a sense of how much experience we have with it.
* When you initially think about a concept, such as a rambutan, activity spikes in the perirhinal cortex. It's as if this area of the brain is trying to match the word to a template you haven't yet created. In the aftermath of that encounter, the neural coalitions in this area get reorganized. The next time you think about rambutans, there's less activity because the election is resolved faster. The tweaking that happens after repeatedly seeing that word improves the brain's efficiency, reducing brain activity in the perirhinal cortex and making it easier to access the concept of rambutans.
* We often (mis)use familiarity as a heuristic, or mental shortcut, to guide decisions. Moreover, we can be blissfully unaware of these influences and instead reinforce our sense of free will by constructing stories that assign meaning to our choices and actions.
* Experience doesn't just change what you see, it changes what you look for. People tend to pay attention to the features that best distinguish faces of people from their own race, at the expense of features that help us recognize faces from other races.
* Like every other aspect of memory, familiarity has both a good and a bad side. It can be a useful by-product of how the brain is constantly becoming more efficient in its perceptions, but its slippery nature means that the fluency that results from mere exposure to something can operate under the radar of awareness, influencing our choices, judgments, and behavior. When we go on autopilot, familiarity can constrain our options and leave us with a smaller world.

== Turn and Face the Strange ==
* Memory's most important feature - orienting us to the future.
* Our memories of the past - "the old" - enable us to allocate critical resources to what is new and what has changed.
* Prediction errors initiate a cycle in the brain in which memory orients us to the unexpected, stimulating curiosity and motivating us to explore and resolve the gaps between our predictions and what we face in the present.
* Our eyes move about 4 times a second.
* When entering a space, we have:
** General knowledge (semantic memory) of what is supposed to be in a particular place.
** Familiarity - our eyes don't linger on things that are familiar, because we don't need to work as hard to process information about familiar objects, faces, or places.
* A major evolutionary function of the hippocampus is to tall us about places that are new or different, so we can explore and learn about these aread.
* Seeing something new or out of place should trigger a signal from the hippocampus stimulating us to explore out surroundings.
* Activity in the hippocampus increased when the subjects looked at pictures of new places.
* The brain's response to what is new is tightly coupled to our ability to remember what we have previously encountered, and that a loss of this novelty response may be an early indicator of risk for Alzheimer's disease.
* The hippocampus is critical for attuning our attention to changes in our environment.
* We might rely on these hippocampal memories to guide what to expect in the here and now. If something isn't in the right place, your spider-sense goes off, and your brain sends a signal to your eyes to scan that area so you can figure out what happened.
* Seeing the place was enough to trigger retrieval of a memory from the hippocampus.
* The hippocampus is one of the most evolutionary ancient structures in the brain.
* The orienting response, is an orchestration of changes in the brain and the body in response to something new or surprising. Our pupils enlarge, increasing sensitivity to light. Blood is pumped to the brain and constricted in the rest of the body, and the brain gets a brief shot of neuromodulators, such as dopamine, noradrenaline, and acetylcholine. There's also a coordinated changes in neural activity throughout a network of brain areas, including the hippocampus and the prefrontal cortex.
* The orienting response is probably one of the most reliable indicators of a functioning hippocampus.
* The hippocampus is like a "What is it?" detector, alerting the brain to something unexpected. It preferentially forms memories for the oddball images.
* Activity in the accumbens spiked about half a second after they saw the oddball image and the findings suggested that surprising or unexpected events can be sufficient to trigger activity in this system even when we do not get an external reward.
* Curiosity is triggered when we discover a discrepancy between what we know and what we'd like to know, a nebulous space "the information gap". Loewenstein proposed that curiosity is about the motivation to seek information, rather than the satisfaction of getting our questions answered. This drive is evolutionarily adaptive because it helps us maintain a balance between exploration (of the new) and exploitation (of the existing).
* By tapping into the reward circuitry, curiosity can enhance memory. This circuitry isn't about rewards, per se; it's about mobilizing us to learn and pursue anything we perceive to have value. And after food, water, and other basic needs are met, this means information.
* People have tendencies, conscious, or unconscious, about whether to respond to the unknown with curiosity or anxiety.

== Press Play and Record ==
* The catalyst for memory updating is the very act of remembering.
* Every time we recall an experience is one link in a neural chain subject to edits and updates, so that, over time, our memories can drift further and further from that initial event.
* We are especially vulnerable to misinformation at the moment of remembering.
* When we revisit a memory over and over, subtle alterations can creep in with each repetition. It's a bit like making a copy of a copy of a copy; the neural connections that hold together a memory are tweaked, and these changes can enlarge some aspects of the experience, while causing us to lose some of the details that keep the memory in focus. Like the fuzzy letters on my college band flyers, events from the distant past can seem more remote and blurry every time we call upon them, and noise becomes more prominent, corrupting the memory a bit more each time it's recalled.
* They made a painstakingly detailed computer model of hippocampus!
* Implanted memories, such as being lost in a mall are not entirely false; rather they are most likely imaginative constructions that incorporate information from schemas and details from real experiences.
* Memory is malleable, but it isn't mush.
* The sequence of steps in consolidation seems to happen whenever we retrieve a memory.
* We already know that memories can be strengthened, weakened, or modified from the moment they are pulled up. This kind of memory updating is at the heart of psychotherapy, which is fundamentally about changing connections that we made in the past in the face of new information. The goal isn't to erase someone's memories of what happened but to adaptively update memories and change one's relationship with the past by approaching it from a different perspective.

== Some Pain, More Gain ==
* Error-driven learning is how we learn to make skilled movements by observing the difference between what we intend to do and what we actually do.
* The benefits of testing do not come from making mistakes per se, but rather from challenging yourself to pull up what you have learned. To understand why, let's go back to our cell assemblies analogy. When you test yourself, your brain will try to generate the right answer, but the result isn't quite perfect.
* Stress testing your memory like this exposes the weaknesses in the cell assemblies so that the memory can be updated, strengthening the useful connections and pruning the one that are gettin in the way. Rather than relearning the same thing over and over, it's much more efficient to tune up the right neural connections and fix just those parts that we are struggling with. Memory updating is the key, because the most efficient way for our brains to save space and learn quickly is to focus on what we didn't already know.
* Memory is not a collection of isolated islands; it's an ecosystem of interacting cell assemblies.
* Retrieval-induced forgetting - When recalling one memory can make it harder to pull up related memories.
* Retrieval-induced facilitation - When people were tested on one of the facts in an article, the benefits of that test spilled over to related facts.
* The shared episodic memory means that an alliance is built between the cell assemblies that back the different components of the lasagna dinner, and when we recall the lasagna, error-driven learning tightens up the alliance, pulling up other connected elements from the same event.
* The spacing effect - if you keep returning to the same information periodically, the hippocampus can continually update those memories until they have no discernible context, making it easier to access them in any place at any time.
* During sleep, the brain goes back and forth between at least five different states. Slow-wave sleep (SWS) and rapid eye movement (REM sleep work hand-in-hand to transform our recent experiences into knowledge that we can use:
** SWS is the deepest sleep stage - there is a fully orchestrated interaction between the hippocampus and the neocortex during SWS. Large, slowly traveling electrical waves cycle across the neocortex, with smaller waves of activity called spindles riding atop the crest. Meanwhile in the hippocampus, little bursts of activity called ripples bubble up, and during each ripple, individual neurons in the hippocampus that were active during the daytime come back to life, firing off in little sequences. Ripples, in turn, trigger bursts of activity in the default mode network (DMN), which helps us use schemas to learn about new events, and in the prefrontal cortex, which helps us intelligently use schemas to form memories for events and reconstruct them later on.
** REM is when dreams occur, and the dynamics of neocortical activity during REM might explain the vivid, lifelike experiences and bizarre logic that accompany our dreaming life. During REM sleep, the brain is generating its on sensory input and tries to make sense of it in the form of dreams, constructing an alternate reality all while you are in bed.
* Sleep may create an environment where cell assemblies active during different events play well together, rather than competing. When information from one event was reactivated in the model, the neocortex used this information to initiate a chain reaction of free associations. Information from different events was reconciled through error-driven learning, bringing out what was common across different events. The model suggest that when memories are reactivated during a test, error-driven learning helps to strengthen those specific memories, but when memories are reactivated during sleep, error-driven learning helps the brain to use threads of disparate experiences to weave a tapestry of knowledge.
* Sleep helps us integrate what we have recently learned across different events so we can use that information more efficiently. Memories for events sometimes become less context-dependent after sleep, and we are sometimes better at seeing big-picture relationships between small pieces of information that we had previously learned, and we are better able to use this information to solve problems.
* Sleep can allow us to convert memory into wisdom.
* The hippocampus helps us pull up specific patterns of brain activity that take us back to a particular place and time, whereas the neocortex stores the semantic knowledge that enables us to understand what happens in an event and make predictions and inferences in new situations. During SWS, the hippocampus can ignite cell assemblies that captured important experiences from the previous day (episodic memory), and then during REM, the neocortex can play around with this information, free-associating to discover possible connections between different events we've experienced.

== When We Remember Together ==

[[Category:Consciousness]]
[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-20T15:18:26Z

Rob: /* Some Pain, More Gain */

== Where is My Mind? - The Neocortex ==

* By one estimate, the average American is exposed to 34GB (or 11.8hr) of information a day
* Hermann Ebbinghaus “On Memory: A contribution to Experimental Psychology (1885) - tried to memorize trigrams, established the idea of a forgetting curve over time.
* In essence, neurons function like a democracy with alliances or “cell assemblies”.
* Somewhere is the brain’s speech centers a large coalition of neurons cases votes for “bath”, a smaller coalition votes for “path”, and an even smaller minority votes for other candidates. Within less than half a second, the vote is tallied, and ultimately the baby picks up that it is time for a bath. The connections between the neutaons that supported bath are strengthened, and connections with neurons that voted for the wrong sound are weakened. As those neurons settle into coalitions that differentiate between the sound the baby is hearing, they are becoming less sensitive to sound differences that don’t exist in that language. It’s as if the neurons are choosing between a small number of candidates based on a few key issues.
* The connections in your brain are constantly being reshaped with the goal of improving your perception, movement, and thinking as you gain more and more experiences. Moreover, as you go past simple perception (what we see, hear, touch, taste, and smell) and move into higher-order functions (eg judgement, evaluation, and problem-solving), the brain is remarkably plastic, and the neural elections are highly contested.
* Interference - there is an intense competition between the coalition that has the memory you’re looking for and coalitions representing other memories you don’t need at that moment.
* The memories that are the most distinctive are the easiest to remember because they stand out relative to everything else.
* Attention - is our brain’s way of prioritizing what we are seeing, hearing, and thinking about.
* Intention - guide’s your attention to lock on to something specific.
* The prefrontal cortex:
** I the “central executive” of the brain. Several regions all over the brain have relatively specialized functions, and the job of the prefrontal cortex is to serve as a central executive, coordinating activity across these networks in the service of the mutual aim.
** Helps us learn with attention
** Takes up about a third of the real estate in the human brain
** Frontal lobotomy - removal of the prefrontal cortex - but rather than treating any underlying mental illness, it leaves patients in a zombielike state, apathetic, docile, and devoid of motivation.
** The more numbers people had to keep in mind, the more activity was apparent in the prefrontal cortex - it plays a part in temporarily holding information.
** People without a functioning prefrontal cortex could do fine when they were given clear instructions and no distractions, but they struggled when they had to spontaneously use memory strategies or follow through on a task when irrelevant things competed for their attention.
** Is intensively activated when a person had to use intention to stay on task, focus on distinctive information, resist distractions, or initiate some kind of mnemonic strategy.
** ADHD is associated with atypical activity in the prefrontal cortex.
** As we get older, we can still learn, but we have more trouble focusing on the details we want to take in and we often end up learning things that might be irrelevant.
** Certain part of the prefrontal cortex are thinned out, on average, in people who do heavy media multitasking.
* Use intention to guide our attention so we can remember what matters. Balance the needs of the experiencing self and the remembering self.

== Travelers of Time and Space - The Hippocampus ==
* We often think about memory as a record of what happened, but the human brain has the remarkable capability to link up the “what” with the where, when, and how. This explains why the experience of remembering is so often accompanied by an ephemeral sense of pastness that’s almost impossible to put into words. It’s also why, if we are in the right place at the right time, lost memories seem to find us.
* That sense of being in a particular time and place is called context, and it is critical for our day-to-day memory experiences. A great deal of everyday forgetting happens not because our memories have disappeared but because we can’t find our way back to them. In the right context, however, memories that have seemed long gone can suddenly resurface back to the forefront of our recall.
* Endel Tulving, in 1972, coined the term “episodic memory” to differentiate from “semantic memory”. To remember an event (episodic memory), we need to mentally return to a specific place and time; but to have knowledge (semantic memory), we need to be able to use what we previously learned across a range of contexts.
* For Tulving remembering puts us in a state of consciousness in which we feel as if we were transported to the past. A key characteristic of human consciousness is that we are “capable of mental time travel, roaming at will over what has happened as readily as over what might happen, independently of the physical laws that govern the universe.”
* You can confidently pull up facts about Paris (semantic memory) and vividly reexperience a trip to Paris (episodic memory), yet the two experiences are totally different.
* AIs have problems with “catastrophic forgetting”, where they learn a rule and then an exception to the rule makes them then throw away everything they had learnt around that rule to date. But we have episodic memory, which is not designed to capture the common elements of all our experiences; it stores and indexes every event differently, so you don’t get mixed up when you learn the exception to the rule.
* The neocortex works like a traditional neural network, enabling us to pick up facts, while the hippocampus is responsible for the brain’s amazing ability to rapidly create new memories for events.
* Brenda Milner, in 1957, published a paper about Patient H.M., Henry Molaison who had his seizures treated by removing about 5cm of tissue from the left and right hippocampus. Milner’s paper definitively linked the formation of new memories to the hippocampus.
* Ranganath suggested that the pattern of light and dark pixels identified by fMRI might be a unique configuration acting as a pointer to a particular memory like a QR code. When thinking about two separate episodic memories about the same person, the neocortex seemed to store the general facts about who and what were in the event, while in the hippocampus, the memory codes for the two related events looked totally different.
* The cell assemblies that allow us to remember particular parts of an event are in separate areas of the brain that normally do not talk to one another. The only thing they have in common is that they were active around the same time. The hippocampus, however, has connections to many of these areas, and its job is to store links to the different cell assemblies that come to life at a given moment. If you revisit the place, then the hippocampus would help reactivate all those cell assemblies, enabling you to reexperience seeing your friend. The hippocampus enables us to “index” memories for different events according to when and where they happened, not according to what happened. Because it organizes memories according to the context, recalling something from one event makes it easier to retrieve other events that happened around the same time or place, painting a fuller picture.
* Pulling up a memory of the recent past helps to ground you in the here and now. According to one prominent theory, episodic memory emerged in evolution from the more basic ability to learn where we are in the world.
* Sea lions without a functioning hippocampus grow disoriented. Lost, and unable to recall their foraging sites, they become malnourished and ultimately stranded onshore.
* The hippocampus is one of the first areas of the brain ravaged by Alzheimer’s, and this is probably why patients in the early stages frequently get lost and lost track of the passage of time. You see the look of fear on a face when a patient becomes unmoored from their sense of when and where they are in the world, like treading water in the open ocean.
* All the external factors from our environment, along with the motivations, thoughts, and feelings that characterize our internal world, come together to form the unique context that envelops our experience at any given time. When we access a particular episodic memory, we can pull up a bit of that past mental state, too.
* Two events that occurred close together in time are going to have more contextual elements in common than events that occurred further apart in time.
* Place, smells, tastes, and music are all powerful cues for episodic memories.
* Our emotions also contribute to context, which means that our feelings in the present affect what we can recall from the past. When we get angry, it’s easy to pull up all those memories that give us more reasons to be annoyed, and it’s harder to access the memories that don’t.
* The essential trick performed by the hippocampus is that it takes in information about the things in which we are interested, and it ties it up with information about the context, all the other stuff that’s going on in the background. We experience zillions of repetitive events, but the context makes each unique, and we can use context as a lifeline to find our way back to those things we seem to always lose.
* The further back in time you try to go, the harder it is for your brain to pull up a past context, and in some cases you won’t be able to do it. Science backs infantile amnesia where you can’t have episode memories before the age of two because the hippocampus is still developing and the entire neocortex is being massively reorganized.
* Event boundaries. We naturally update our sense of context when we experience a shift in our perception of the world around us, and those points mark the boundary between one event and another. People are better at remembering information that occurred at an event boundary then they are at remembering information from the middle of the event, and this is because the hippocampus waits to store a memory for an event until right after an event boundary - so we only encode the memory once we have a full understanding of the event.
** Event boundaries happen all the time and don’t necessarily require a change in location. Anything that alters your sense of the current context - a shift in the topic of conversation, a change in your immediate goals, or the onset of something surprising - can lead you to put up an event boundary.
* During the Covid epidemic, confined to home and with few event boundaries to provide meaningful structure to their lives, millions of people all over the world felt as if they were living in the twilight zone, floating aimlessly through time and space.
* Nostalgia - on average, people find it easier to recall positive experiences than negative ones, and this positivity bias increases as we get older, which might explain older adults’ penchant for nostalgia.
** The reminiscence bump - when we look back at the past, we tend to focus on a specific period of our lives, between the ages of ten and thirty - something about listing to a song or watching a movie from those formative years can give us a sense of meaning, connecting us to an idealized sense of who we are.
** The cost of nostalgia is that it can leave us feeling disconnected from our lives in the present, giving us a sense that things aren’t as they were in the “good old days”.
* Rumination - is the evil twin of nostalgia, and a prime example of how not to use episodic memory.

== Reduce, Reuse, Recycle - Schemas and the Default Mode Network (DMN) ==
* We can keep up to only 3-4 pieces of information in mind at once, but there is a huge loophole: there is no set definition for what constitutes one piece of information. Chunking allows us to compress massive amounts of data into a manageable amount of information that is easily accessible.
* Like memory athletes, chess grand masters use a combination of skill, training, and experience - aka expertise - to chunk at lightning speed. Expertise changes the way we mobilize the prefrontal cortex. Experts develop particular ways to extract the most useful information about what they are trying to remember, allowing them to bypass the limitations of memory by leveraging their expertise.
* Expertise isn't just about seeing patterns, it's about the way we find them. As we gain expertise in any topic, we can exploit what we have learned to focus on the most important bits of new information that we need.
* The human brain is not a memorization machine; it's a thinking machine.
* A schema is a kind of mental framework that allows our minds to process, organize, and interpret a great deal of information with minimal effort. A schema is like a blueprint for a space or an event. Event schemas provide the structure that allows us to rapidly form memories for a complex event. They are like scripts for ordering coffee, meeting a colleague, going to the cinema, etc.
* In some way or another, every expert exploits the power of schemas to organize what they need to remember into a framework they can access later.
* The Default Mode Network (DMN) is a set of neocortical areas that consume the most energy in the brain, yet activity in these areas seems to go down when people are focusing their attention on some arbitrary task. Brain activity in the hippocampus is tightly linked with what is going on in the DMN. It seems that cell assemblies in the DMN store the schemas we use to understand the world, dissecting the events we experience into pieces so that we can use them in new ways to construct new memories. The hippocampus could, in turn, put the pieces together to store a specific episodic memory.
* In an experiment about watching and recounting the plots of movies:
** The DMN was providing the raw materials needed to understand and remember each movie, but it was not storing context-specific episodic memories. Instead of storing a unique memory code for each movie, the DMN was breaking up each movie into components that were repeatedly reused to understand or remember other movies that shared the same components. Memory codes in one part of the DMN could tell us whether the subject was watching or remembering a movie that took place in a supermarket or a café, whereas memory codes in a different part of the DMN could tell us whether A or B was the star in the movie.
** In contrast to the DMN, the hippocampus, which supports episodic memory by putting together information from all over the brain - did have a separate memory code for each movie. And unlike the DMN, the hippocampus only seemed to store a memory for the beginning and end of each movie (ie, the event boundaries).
** Thanks to the DMN, I can reuse my supermarket schema every time I shop for groceries, and I can reuse my A schema every time I see A. And thanks to the hippocampus, I can also form different memories for every specific occasion that I run into A at the supermarket.
* Forming an episodic memory is a bit like building with LEGOs, breaking down models and using the independent components again and again in different contexts.
* It's now clear that amyloid - a protein implicated in the development of Alzheimer's disease - accumulates in the DMN in about 20% of older adults long before any symptoms are apparent.
* A chess grand master has a library of chess game schemas, each containing templates for entire sequences of moves you typically see in a game. Those schemas allow them to remember sequences of moves in past games, to understand what is happening in a game in real time, and to predict likely moves that an opponent could make in the future. By exploiting that expert knowledge, a seemingly complex configuration of pieces can easily be understood as one step in a series of moves that might wipe out a number of pieces and lead to a checkmate.
* Schemas allow us to see through an event, capturing the deeper structures of how everything is connected. In doing so, we can compress memories of hundreds, even thousands, of experiences into a format that enables us to make inferences and predictions about events we haven't yet experienced. Schemas allow us to use knowledge about what has happened to get a head start on what will happen.

== Just My Imagination ==
* Shereshevsky - the capacity of his memory had no distinct limits.
* He may have had synesthesia - every stimulus, regardless of which sense it came through, triggered every other sense. He could taste words, see music and smell colors.
* The connection between the worlds he created in his mind and the world he lived in was so visceral that he could elevate his hear rate by simply imagining he was running for a train. He could raise the temperature of one hand and lower the other by picturing one hand on a stove and the other resting on a block of ice.
* The brain activity changes that occur when people imagine these kinds of scenarios are remarkably similar to those that occur when people recall events that they actually experienced.
* "Remembering is not the re-excitation of innumerable fixed, lifeless and fragmentary traces. It is an imaginative reconstruction." We do not simply replay a past event, but use a small amount of context and retrieved information as a starting point to imagine how the past could have been. We put together a story on the fly, based on our personal and cultural experiences, and tack on those retrieved details to flesh out the story. Bartlett's insight is key to understanding why the brain's machinery for imagination and for memory aren't completely independent - they are both based on pulling up knowledge about what can happen, though not necessarily what did happen.
* The hippocampus might get us back to some of the cell assemblies that were active during some moments in a conversation, but we still need to use schemas in the default network to make sense of what we are pulling up. this reconstruction is prone to error, however, because schemas capture what typically happens, not what did happen.
* Our minds are constantly churning with what-ifs. We conjure up scenarios for what could happen in the future, and we wonder what our present would be like if past events had turned out differently. All the scenarios we imagine leave us with memories of events we have never experienced, and our memories don't come with labels certifying them as imagined or real.
* So we need reality monitoring. The more sensory details that come to mind when you remember an event, the more likely it is that it really happened, because on average what we imagine is not as detailed as what we have experienced.
* We can counteract the fallibility of memory by considering not only the quality of the details that seem to put us back in a specific place and time but also the likelihood that those details could have been constructed to create an alternative reality. As with all critical thinking, it helps to remain skeptical until presented with further evidence.
* Monitoring the details of our memories engages the most evolutionarily advanced areas of the human prefrontal cortex.
* Confabulation: Some people who have extensive damage to the prefrontal cortex can confidently recall things that never happened. We all are guilty of minor confabulations. When we're tired or stressed out, or when our attention is divided by multitasking, reality monitoring goes out the window. As we get older, prefrontal function gets words, and we find it harder to tell the difference between imagination and experience.
* In 1928, Bartlett speculated that creative works are constructed by essentially doing the opposite of reality monitoring - that is, by pulling up fragments of memories and then assembling those bits and pieces into a cohesive product of imagination.
* The hippocampus and the DMN might function at the crossroads between memory and imagination by allowing us to extract the ingredients from past experiences and recombine them into new creations.
* AI art is not about generating something new, it's about taking elements from preexisting human art and recombining them (based on human direction and curation).
* We now know that it is in that space where memory meets imagination that we interpret reality and create our greatest treasures.

== More Than a Feeling - the Amygdala ==
* Our emotions, as well as the actions and choices they influence, are shaped by basic survival circuits in the brain that motivate us to avoid threats, find sustenance, and reproduce. When these circuits go into overdrive, we tend to experience intense emotions, such as elation, lust, panic, anxiety, or disgust. These are experiences we remember most vividly, because they provide valuable information that we can use in the future to stay safe, thrive, and reproduce.
* Neuromodulators promote plasticity, enabling long-lasting changes in the connections between neurons in the cell assemblies that are activated when we learn something new.
* Noradrenaline (AKA norepinephrine) is released all over the brain in response to threats. Emotional arousal changes what we will remember, rather than simply how much. If you get mugged your attention will be on the weapon pointed at you rather than the mugger's shoes. It's easy to forget more mundane experiences, but hard to let go of a traumatic memory: our brains are designed to hold on to the events that revved us up, ostensibly because remembering those events has survival value.
* When we recall a time our survival circuits were called into action, the hippocampus works with the amygdala. As the hippocampus forms memories that capture the context at that moment, the amygdala is connecting those memories with the survival circuits that generate the raw sensations. Later on, when remembering, the amygdala brings us back to the heat of the moment, making us feel as if we are vividly reexperiencing the event.
* We feel anxious when we think something bad might happen, but we cannot predict or control whether it will happen.
* Cortisol spikes when you are stressed out to improve your ability to retain memories for what happened right before or after the stressful event. Like noradrenaline, stress hormones seem to promote plasticity, initiating the cascade of changes that consolidate connections within the cell assemblies representing the memory for a stressful event.
* Stress tips the chemical balance in the brain, downregulating the executive functions mediated by the prefrontal cortex and enhancing the sensitivity of the amygdala.
* In the healthy brain, if the hippocampus does its job, then memories for traumatic events should be associated with a specific context. Hippocampal dysfunction in experimentally stressed lab animals, and in humans with PTSD may cause traumatic memories to become overgeneralized.
* Dopamine is central to helping us form lasting memories for rewarding experiences. Like other neuromodulators, dopamine promotes plasticity, and its release tends to be concentrated in several brain areas that are important for helping us learn how to get rewards:
** Dopamine in the amygdala helps us learn about cues that signal an upcoming reward.
** In the hippocampus, it helps us learn about the contexts where we are likely to get rewards.
** in the nucleus accumbens, it helpus us learn what we need to do to get the reward.
* Over all, dopamine associates cues, contexts, and actions that lead to rewards and sets expectations that shape our experience when we get them.
* We are wired to learn only when the outcomes don't match up with our expectations.
* Sudden drops in dopamine activity drain motivation, while an increase in dopamine activity can be energizing.
* We often feel intensely motivated to seek out a reward even when we know it won't necessarily be pleasurable - cheating on a diet, smoking a cigarette when we have quit - this is the result of dopamine driving us.
* In gambling studies, when people unexpectedly won a bet, we saw a large neural response, but when they expected to win and did, we saw only a small neural response. if a person had a large neural response after seeing the outcome of the bet, they would be more likely to make the same bet next. The people who favored risky bets showed more activity in reward-learning circuits when they won than people who tended to play it safe. And unlike risk-averse subjects, risk-takers still got a bump of activity in the reward circuit even when they lost a risky bet. At least some people might have a reward-learning circuit that leads them to persist in making risky decisions even after bad outcomes.
* Cocaine, meth, heroin, opioids, and alcohol all activate the dopamine system, and can lead to powerful addictions.

== All Around Me Are Familiar Faces ==
* We tend to be more interested in exploring things that are new to us, than in things we have seen before.
* Electrical signals in the perirhinal cortex can artificially produce a sense of intense familiarity or novelty. This suggests that it might be responsible for that sense of familiarity we naturally experience when we visit a place or see a person we have seen before.
* The more activity in the perirhinal cortex when our volunteers read a word in the MRI scanner, the more familiar that word would seem when they saw it again on the surprise test. And, unlike with the hippocampus, activity in the perirhinal cortex was not related to people's ability to recollect the context of words that they had studied. Memories are not just strong of weak; rather the human brain has two different kinds of memory:
** Episodic memory, which is supported by the hippocampus
** Familiarity, which is supported by the perirhinal cortex.
* Cell assemblies all over the brain are in constant flux, reorganizing and optimizing so that the neural elections that determine our perceptions, thoughts, and actions will come to swift and decisive conclusions. When those tweaks happen in sensory areas, they help us read, see, and experience the world more efficiently. Those little tweaks also happen in higher-level areas of the brains, such as the perirhinal cortex, that integrate information from our different senses to help build semantic memories.
* All this neural plasticity seems to happen without our awareness, but the outcome can be sensed. the more familiar we become with something, the more our cell assemblies become fine-tune to recognize that thing later on. So, if we pay attention to how much mental effort we put in to read a word or recognize a face, we can get a sense of how much experience we have with it.
* When you initially think about a concept, such as a rambutan, activity spikes in the perirhinal cortex. It's as if this area of the brain is trying to match the word to a template you haven't yet created. In the aftermath of that encounter, the neural coalitions in this area get reorganized. The next time you think about rambutans, there's less activity because the election is resolved faster. The tweaking that happens after repeatedly seeing that word improves the brain's efficiency, reducing brain activity in the perirhinal cortex and making it easier to access the concept of rambutans.
* We often (mis)use familiarity as a heuristic, or mental shortcut, to guide decisions. Moreover, we can be blissfully unaware of these influences and instead reinforce our sense of free will by constructing stories that assign meaning to our choices and actions.
* Experience doesn't just change what you see, it changes what you look for. People tend to pay attention to the features that best distinguish faces of people from their own race, at the expense of features that help us recognize faces from other races.
* Like every other aspect of memory, familiarity has both a good and a bad side. It can be a useful by-product of how the brain is constantly becoming more efficient in its perceptions, but its slippery nature means that the fluency that results from mere exposure to something can operate under the radar of awareness, influencing our choices, judgments, and behavior. When we go on autopilot, familiarity can constrain our options and leave us with a smaller world.

== Turn and Face the Strange ==
* Memory's most important feature - orienting us to the future.
* Our memories of the past - "the old" - enable us to allocate critical resources to what is new and what has changed.
* Prediction errors initiate a cycle in the brain in which memory orients us to the unexpected, stimulating curiosity and motivating us to explore and resolve the gaps between our predictions and what we face in the present.
* Our eyes move about 4 times a second.
* When entering a space, we have:
** General knowledge (semantic memory) of what is supposed to be in a particular place.
** Familiarity - our eyes don't linger on things that are familiar, because we don't need to work as hard to process information about familiar objects, faces, or places.
* A major evolutionary function of the hippocampus is to tall us about places that are new or different, so we can explore and learn about these aread.
* Seeing something new or out of place should trigger a signal from the hippocampus stimulating us to explore out surroundings.
* Activity in the hippocampus increased when the subjects looked at pictures of new places.
* The brain's response to what is new is tightly coupled to our ability to remember what we have previously encountered, and that a loss of this novelty response may be an early indicator of risk for Alzheimer's disease.
* The hippocampus is critical for attuning our attention to changes in our environment.
* We might rely on these hippocampal memories to guide what to expect in the here and now. If something isn't in the right place, your spider-sense goes off, and your brain sends a signal to your eyes to scan that area so you can figure out what happened.
* Seeing the place was enough to trigger retrieval of a memory from the hippocampus.
* The hippocampus is one of the most evolutionary ancient structures in the brain.
* The orienting response, is an orchestration of changes in the brain and the body in response to something new or surprising. Our pupils enlarge, increasing sensitivity to light. Blood is pumped to the brain and constricted in the rest of the body, and the brain gets a brief shot of neuromodulators, such as dopamine, noradrenaline, and acetylcholine. There's also a coordinated changes in neural activity throughout a network of brain areas, including the hippocampus and the prefrontal cortex.
* The orienting response is probably one of the most reliable indicators of a functioning hippocampus.
* The hippocampus is like a "What is it?" detector, alerting the brain to something unexpected. It preferentially forms memories for the oddball images.
* Activity in the accumbens spiked about half a second after they saw the oddball image and the findings suggested that surprising or unexpected events can be sufficient to trigger activity in this system even when we do not get an external reward.
* Curiosity is triggered when we discover a discrepancy between what we know and what we'd like to know, a nebulous space "the information gap". Loewenstein proposed that curiosity is about the motivation to seek information, rather than the satisfaction of getting our questions answered. This drive is evolutionarily adaptive because it helps us maintain a balance between exploration (of the new) and exploitation (of the existing).
* By tapping into the reward circuitry, curiosity can enhance memory. This circuitry isn't about rewards, per se; it's about mobilizing us to learn and pursue anything we perceive to have value. And after food, water, and other basic needs are met, this means information.
* People have tendencies, conscious, or unconscious, about whether to respond to the unknown with curiosity or anxiety.

== Press Play and Record ==
* The catalyst for memory updating is the very act of remembering.
* Every time we recall an experience is one link in a neural chain subject to edits and updates, so that, over time, our memories can drift further and further from that initial event.
* We are especially vulnerable to misinformation at the moment of remembering.
* When we revisit a memory over and over, subtle alterations can creep in with each repetition. It's a bit like making a copy of a copy of a copy; the neural connections that hold together a memory are tweaked, and these changes can enlarge some aspects of the experience, while causing us to lose some of the details that keep the memory in focus. Like the fuzzy letters on my college band flyers, events from the distant past can seem more remote and blurry every time we call upon them, and noise becomes more prominent, corrupting the memory a bit more each time it's recalled.
* They made a painstakingly detailed computer model of hippocampus!
* Implanted memories, such as being lost in a mall are not entirely false; rather they are most likely imaginative constructions that incorporate information from schemas and details from real experiences.
* Memory is malleable, but it isn't mush.
* The sequence of steps in consolidation seems to happen whenever we retrieve a memory.
* We already know that memories can be strengthened, weakened, or modified from the moment they are pulled up. This kind of memory updating is at the heart of psychotherapy, which is fundamentally about changing connections that we made in the past in the face of new information. The goal isn't to erase someone's memories of what happened but to adaptively update memories and change one's relationship with the past by approaching it from a different perspective.

== Some Pain, More Gain ==
* Error-driven learning is how we learn to make skilled movements by observing the difference between what we intend to do and what we actually do.
* The benefits of testing do not come from making mistakes per se, but rather from challenging yourself to pull up what you have learned. To understand why, let's go back to our cell assemblies analogy. When you test yourself, your brain will try to generate the right answer, but the result isn't quite perfect.
* Stress testing your memory like this exposes the weaknesses in the cell assemblies so that the memory can be updated, strengthening the useful connections and pruning the one that are gettin in the way. Rather than relearning the same thing over and over, it's much more efficient to tune up the right neural connections and fix just those parts that we are struggling with. Memory updating is the key, because the most efficient way for our brains to save space and learn quickly is to focus on what we didn't already know.
* Memory is not a collection of isolated islands; it's an ecosystem of interacting cell assemblies.
* Retrieval-induced forgetting - When recalling one memory can make it harder to pull up related memories.
* Retrieval-induced facilitation - When people were tested on one of the facts in an article, the benefits of that test spilled over to related facts.
* The shared episodic memory means that an alliance is built between the cell assemblies that back the different components of the lasagna dinner, and when we recall the lasagna, error-driven learning tightens up the alliance, pulling up other connected elements from the same event.
* The spacing effect - if you keep returning to the same information periodically, the hippocampus can continually update those memories until they have no discernible context, making it easier to access them in any place at any time.
* During sleep, the brain goes back and forth between at least five different states. Slow-wave sleep (SWS) and rapid eye movement (REM sleep work hand-in-hand to transform our recent experiences into knowledge that we can use:
** SWS is the deepest sleep stage - there is a fully orchestrated interaction between the hippocampus and the neocortex during SWS. Large, slowly traveling electrical waves cycle across the neocortex, with smaller waves of activity called spindles riding atop the crest. Meanwhile in the hippocampus, little bursts of activity called ripples bubble up, and during each ripple, individual neurons in the hippocampus that were active during the daytime come back to life, firing off in little sequences. Ripples, in turn, trigger bursts of activity in the default mode network (DMN), which helps us use schemas to learn about new events, and in the prefrontal cortex, which helps us intelligently use schemas to form memories for events and reconstruct them later on.
** REM is when dreams occur, and the dynamics of neocortical activity during REM might explain the vivid, lifelike experiences and bizarre logic that accompany our dreaming life. During REM sleep, the brain is generating its on sensory input and tries to make sense of it in the form of dreams, constructing an alternate reality all while you are in bed.
* Sleep may create an environment where cell assemblies active during different events play well together, rather than competing. When information from one event was reactivated in the model, the neocortex used this information to initiate a chain reaction of free associations. Information from different events was reconciled

== When We Remember Together ==

[[Category:Consciousness]]
[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-20T14:57:44Z

Rob: /* Press Play and Record */

== Where is My Mind? - The Neocortex ==

* By one estimate, the average American is exposed to 34GB (or 11.8hr) of information a day
* Hermann Ebbinghaus “On Memory: A contribution to Experimental Psychology (1885) - tried to memorize trigrams, established the idea of a forgetting curve over time.
* In essence, neurons function like a democracy with alliances or “cell assemblies”.
* Somewhere is the brain’s speech centers a large coalition of neurons cases votes for “bath”, a smaller coalition votes for “path”, and an even smaller minority votes for other candidates. Within less than half a second, the vote is tallied, and ultimately the baby picks up that it is time for a bath. The connections between the neutaons that supported bath are strengthened, and connections with neurons that voted for the wrong sound are weakened. As those neurons settle into coalitions that differentiate between the sound the baby is hearing, they are becoming less sensitive to sound differences that don’t exist in that language. It’s as if the neurons are choosing between a small number of candidates based on a few key issues.
* The connections in your brain are constantly being reshaped with the goal of improving your perception, movement, and thinking as you gain more and more experiences. Moreover, as you go past simple perception (what we see, hear, touch, taste, and smell) and move into higher-order functions (eg judgement, evaluation, and problem-solving), the brain is remarkably plastic, and the neural elections are highly contested.
* Interference - there is an intense competition between the coalition that has the memory you’re looking for and coalitions representing other memories you don’t need at that moment.
* The memories that are the most distinctive are the easiest to remember because they stand out relative to everything else.
* Attention - is our brain’s way of prioritizing what we are seeing, hearing, and thinking about.
* Intention - guide’s your attention to lock on to something specific.
* The prefrontal cortex:
** I the “central executive” of the brain. Several regions all over the brain have relatively specialized functions, and the job of the prefrontal cortex is to serve as a central executive, coordinating activity across these networks in the service of the mutual aim.
** Helps us learn with attention
** Takes up about a third of the real estate in the human brain
** Frontal lobotomy - removal of the prefrontal cortex - but rather than treating any underlying mental illness, it leaves patients in a zombielike state, apathetic, docile, and devoid of motivation.
** The more numbers people had to keep in mind, the more activity was apparent in the prefrontal cortex - it plays a part in temporarily holding information.
** People without a functioning prefrontal cortex could do fine when they were given clear instructions and no distractions, but they struggled when they had to spontaneously use memory strategies or follow through on a task when irrelevant things competed for their attention.
** Is intensively activated when a person had to use intention to stay on task, focus on distinctive information, resist distractions, or initiate some kind of mnemonic strategy.
** ADHD is associated with atypical activity in the prefrontal cortex.
** As we get older, we can still learn, but we have more trouble focusing on the details we want to take in and we often end up learning things that might be irrelevant.
** Certain part of the prefrontal cortex are thinned out, on average, in people who do heavy media multitasking.
* Use intention to guide our attention so we can remember what matters. Balance the needs of the experiencing self and the remembering self.

== Travelers of Time and Space - The Hippocampus ==
* We often think about memory as a record of what happened, but the human brain has the remarkable capability to link up the “what” with the where, when, and how. This explains why the experience of remembering is so often accompanied by an ephemeral sense of pastness that’s almost impossible to put into words. It’s also why, if we are in the right place at the right time, lost memories seem to find us.
* That sense of being in a particular time and place is called context, and it is critical for our day-to-day memory experiences. A great deal of everyday forgetting happens not because our memories have disappeared but because we can’t find our way back to them. In the right context, however, memories that have seemed long gone can suddenly resurface back to the forefront of our recall.
* Endel Tulving, in 1972, coined the term “episodic memory” to differentiate from “semantic memory”. To remember an event (episodic memory), we need to mentally return to a specific place and time; but to have knowledge (semantic memory), we need to be able to use what we previously learned across a range of contexts.
* For Tulving remembering puts us in a state of consciousness in which we feel as if we were transported to the past. A key characteristic of human consciousness is that we are “capable of mental time travel, roaming at will over what has happened as readily as over what might happen, independently of the physical laws that govern the universe.”
* You can confidently pull up facts about Paris (semantic memory) and vividly reexperience a trip to Paris (episodic memory), yet the two experiences are totally different.
* AIs have problems with “catastrophic forgetting”, where they learn a rule and then an exception to the rule makes them then throw away everything they had learnt around that rule to date. But we have episodic memory, which is not designed to capture the common elements of all our experiences; it stores and indexes every event differently, so you don’t get mixed up when you learn the exception to the rule.
* The neocortex works like a traditional neural network, enabling us to pick up facts, while the hippocampus is responsible for the brain’s amazing ability to rapidly create new memories for events.
* Brenda Milner, in 1957, published a paper about Patient H.M., Henry Molaison who had his seizures treated by removing about 5cm of tissue from the left and right hippocampus. Milner’s paper definitively linked the formation of new memories to the hippocampus.
* Ranganath suggested that the pattern of light and dark pixels identified by fMRI might be a unique configuration acting as a pointer to a particular memory like a QR code. When thinking about two separate episodic memories about the same person, the neocortex seemed to store the general facts about who and what were in the event, while in the hippocampus, the memory codes for the two related events looked totally different.
* The cell assemblies that allow us to remember particular parts of an event are in separate areas of the brain that normally do not talk to one another. The only thing they have in common is that they were active around the same time. The hippocampus, however, has connections to many of these areas, and its job is to store links to the different cell assemblies that come to life at a given moment. If you revisit the place, then the hippocampus would help reactivate all those cell assemblies, enabling you to reexperience seeing your friend. The hippocampus enables us to “index” memories for different events according to when and where they happened, not according to what happened. Because it organizes memories according to the context, recalling something from one event makes it easier to retrieve other events that happened around the same time or place, painting a fuller picture.
* Pulling up a memory of the recent past helps to ground you in the here and now. According to one prominent theory, episodic memory emerged in evolution from the more basic ability to learn where we are in the world.
* Sea lions without a functioning hippocampus grow disoriented. Lost, and unable to recall their foraging sites, they become malnourished and ultimately stranded onshore.
* The hippocampus is one of the first areas of the brain ravaged by Alzheimer’s, and this is probably why patients in the early stages frequently get lost and lost track of the passage of time. You see the look of fear on a face when a patient becomes unmoored from their sense of when and where they are in the world, like treading water in the open ocean.
* All the external factors from our environment, along with the motivations, thoughts, and feelings that characterize our internal world, come together to form the unique context that envelops our experience at any given time. When we access a particular episodic memory, we can pull up a bit of that past mental state, too.
* Two events that occurred close together in time are going to have more contextual elements in common than events that occurred further apart in time.
* Place, smells, tastes, and music are all powerful cues for episodic memories.
* Our emotions also contribute to context, which means that our feelings in the present affect what we can recall from the past. When we get angry, it’s easy to pull up all those memories that give us more reasons to be annoyed, and it’s harder to access the memories that don’t.
* The essential trick performed by the hippocampus is that it takes in information about the things in which we are interested, and it ties it up with information about the context, all the other stuff that’s going on in the background. We experience zillions of repetitive events, but the context makes each unique, and we can use context as a lifeline to find our way back to those things we seem to always lose.
* The further back in time you try to go, the harder it is for your brain to pull up a past context, and in some cases you won’t be able to do it. Science backs infantile amnesia where you can’t have episode memories before the age of two because the hippocampus is still developing and the entire neocortex is being massively reorganized.
* Event boundaries. We naturally update our sense of context when we experience a shift in our perception of the world around us, and those points mark the boundary between one event and another. People are better at remembering information that occurred at an event boundary then they are at remembering information from the middle of the event, and this is because the hippocampus waits to store a memory for an event until right after an event boundary - so we only encode the memory once we have a full understanding of the event.
** Event boundaries happen all the time and don’t necessarily require a change in location. Anything that alters your sense of the current context - a shift in the topic of conversation, a change in your immediate goals, or the onset of something surprising - can lead you to put up an event boundary.
* During the Covid epidemic, confined to home and with few event boundaries to provide meaningful structure to their lives, millions of people all over the world felt as if they were living in the twilight zone, floating aimlessly through time and space.
* Nostalgia - on average, people find it easier to recall positive experiences than negative ones, and this positivity bias increases as we get older, which might explain older adults’ penchant for nostalgia.
** The reminiscence bump - when we look back at the past, we tend to focus on a specific period of our lives, between the ages of ten and thirty - something about listing to a song or watching a movie from those formative years can give us a sense of meaning, connecting us to an idealized sense of who we are.
** The cost of nostalgia is that it can leave us feeling disconnected from our lives in the present, giving us a sense that things aren’t as they were in the “good old days”.
* Rumination - is the evil twin of nostalgia, and a prime example of how not to use episodic memory.

== Reduce, Reuse, Recycle - Schemas and the Default Mode Network (DMN) ==
* We can keep up to only 3-4 pieces of information in mind at once, but there is a huge loophole: there is no set definition for what constitutes one piece of information. Chunking allows us to compress massive amounts of data into a manageable amount of information that is easily accessible.
* Like memory athletes, chess grand masters use a combination of skill, training, and experience - aka expertise - to chunk at lightning speed. Expertise changes the way we mobilize the prefrontal cortex. Experts develop particular ways to extract the most useful information about what they are trying to remember, allowing them to bypass the limitations of memory by leveraging their expertise.
* Expertise isn't just about seeing patterns, it's about the way we find them. As we gain expertise in any topic, we can exploit what we have learned to focus on the most important bits of new information that we need.
* The human brain is not a memorization machine; it's a thinking machine.
* A schema is a kind of mental framework that allows our minds to process, organize, and interpret a great deal of information with minimal effort. A schema is like a blueprint for a space or an event. Event schemas provide the structure that allows us to rapidly form memories for a complex event. They are like scripts for ordering coffee, meeting a colleague, going to the cinema, etc.
* In some way or another, every expert exploits the power of schemas to organize what they need to remember into a framework they can access later.
* The Default Mode Network (DMN) is a set of neocortical areas that consume the most energy in the brain, yet activity in these areas seems to go down when people are focusing their attention on some arbitrary task. Brain activity in the hippocampus is tightly linked with what is going on in the DMN. It seems that cell assemblies in the DMN store the schemas we use to understand the world, dissecting the events we experience into pieces so that we can use them in new ways to construct new memories. The hippocampus could, in turn, put the pieces together to store a specific episodic memory.
* In an experiment about watching and recounting the plots of movies:
** The DMN was providing the raw materials needed to understand and remember each movie, but it was not storing context-specific episodic memories. Instead of storing a unique memory code for each movie, the DMN was breaking up each movie into components that were repeatedly reused to understand or remember other movies that shared the same components. Memory codes in one part of the DMN could tell us whether the subject was watching or remembering a movie that took place in a supermarket or a café, whereas memory codes in a different part of the DMN could tell us whether A or B was the star in the movie.
** In contrast to the DMN, the hippocampus, which supports episodic memory by putting together information from all over the brain - did have a separate memory code for each movie. And unlike the DMN, the hippocampus only seemed to store a memory for the beginning and end of each movie (ie, the event boundaries).
** Thanks to the DMN, I can reuse my supermarket schema every time I shop for groceries, and I can reuse my A schema every time I see A. And thanks to the hippocampus, I can also form different memories for every specific occasion that I run into A at the supermarket.
* Forming an episodic memory is a bit like building with LEGOs, breaking down models and using the independent components again and again in different contexts.
* It's now clear that amyloid - a protein implicated in the development of Alzheimer's disease - accumulates in the DMN in about 20% of older adults long before any symptoms are apparent.
* A chess grand master has a library of chess game schemas, each containing templates for entire sequences of moves you typically see in a game. Those schemas allow them to remember sequences of moves in past games, to understand what is happening in a game in real time, and to predict likely moves that an opponent could make in the future. By exploiting that expert knowledge, a seemingly complex configuration of pieces can easily be understood as one step in a series of moves that might wipe out a number of pieces and lead to a checkmate.
* Schemas allow us to see through an event, capturing the deeper structures of how everything is connected. In doing so, we can compress memories of hundreds, even thousands, of experiences into a format that enables us to make inferences and predictions about events we haven't yet experienced. Schemas allow us to use knowledge about what has happened to get a head start on what will happen.

== Just My Imagination ==
* Shereshevsky - the capacity of his memory had no distinct limits.
* He may have had synesthesia - every stimulus, regardless of which sense it came through, triggered every other sense. He could taste words, see music and smell colors.
* The connection between the worlds he created in his mind and the world he lived in was so visceral that he could elevate his hear rate by simply imagining he was running for a train. He could raise the temperature of one hand and lower the other by picturing one hand on a stove and the other resting on a block of ice.
* The brain activity changes that occur when people imagine these kinds of scenarios are remarkably similar to those that occur when people recall events that they actually experienced.
* "Remembering is not the re-excitation of innumerable fixed, lifeless and fragmentary traces. It is an imaginative reconstruction." We do not simply replay a past event, but use a small amount of context and retrieved information as a starting point to imagine how the past could have been. We put together a story on the fly, based on our personal and cultural experiences, and tack on those retrieved details to flesh out the story. Bartlett's insight is key to understanding why the brain's machinery for imagination and for memory aren't completely independent - they are both based on pulling up knowledge about what can happen, though not necessarily what did happen.
* The hippocampus might get us back to some of the cell assemblies that were active during some moments in a conversation, but we still need to use schemas in the default network to make sense of what we are pulling up. this reconstruction is prone to error, however, because schemas capture what typically happens, not what did happen.
* Our minds are constantly churning with what-ifs. We conjure up scenarios for what could happen in the future, and we wonder what our present would be like if past events had turned out differently. All the scenarios we imagine leave us with memories of events we have never experienced, and our memories don't come with labels certifying them as imagined or real.
* So we need reality monitoring. The more sensory details that come to mind when you remember an event, the more likely it is that it really happened, because on average what we imagine is not as detailed as what we have experienced.
* We can counteract the fallibility of memory by considering not only the quality of the details that seem to put us back in a specific place and time but also the likelihood that those details could have been constructed to create an alternative reality. As with all critical thinking, it helps to remain skeptical until presented with further evidence.
* Monitoring the details of our memories engages the most evolutionarily advanced areas of the human prefrontal cortex.
* Confabulation: Some people who have extensive damage to the prefrontal cortex can confidently recall things that never happened. We all are guilty of minor confabulations. When we're tired or stressed out, or when our attention is divided by multitasking, reality monitoring goes out the window. As we get older, prefrontal function gets words, and we find it harder to tell the difference between imagination and experience.
* In 1928, Bartlett speculated that creative works are constructed by essentially doing the opposite of reality monitoring - that is, by pulling up fragments of memories and then assembling those bits and pieces into a cohesive product of imagination.
* The hippocampus and the DMN might function at the crossroads between memory and imagination by allowing us to extract the ingredients from past experiences and recombine them into new creations.
* AI art is not about generating something new, it's about taking elements from preexisting human art and recombining them (based on human direction and curation).
* We now know that it is in that space where memory meets imagination that we interpret reality and create our greatest treasures.

== More Than a Feeling - the Amygdala ==
* Our emotions, as well as the actions and choices they influence, are shaped by basic survival circuits in the brain that motivate us to avoid threats, find sustenance, and reproduce. When these circuits go into overdrive, we tend to experience intense emotions, such as elation, lust, panic, anxiety, or disgust. These are experiences we remember most vividly, because they provide valuable information that we can use in the future to stay safe, thrive, and reproduce.
* Neuromodulators promote plasticity, enabling long-lasting changes in the connections between neurons in the cell assemblies that are activated when we learn something new.
* Noradrenaline (AKA norepinephrine) is released all over the brain in response to threats. Emotional arousal changes what we will remember, rather than simply how much. If you get mugged your attention will be on the weapon pointed at you rather than the mugger's shoes. It's easy to forget more mundane experiences, but hard to let go of a traumatic memory: our brains are designed to hold on to the events that revved us up, ostensibly because remembering those events has survival value.
* When we recall a time our survival circuits were called into action, the hippocampus works with the amygdala. As the hippocampus forms memories that capture the context at that moment, the amygdala is connecting those memories with the survival circuits that generate the raw sensations. Later on, when remembering, the amygdala brings us back to the heat of the moment, making us feel as if we are vividly reexperiencing the event.
* We feel anxious when we think something bad might happen, but we cannot predict or control whether it will happen.
* Cortisol spikes when you are stressed out to improve your ability to retain memories for what happened right before or after the stressful event. Like noradrenaline, stress hormones seem to promote plasticity, initiating the cascade of changes that consolidate connections within the cell assemblies representing the memory for a stressful event.
* Stress tips the chemical balance in the brain, downregulating the executive functions mediated by the prefrontal cortex and enhancing the sensitivity of the amygdala.
* In the healthy brain, if the hippocampus does its job, then memories for traumatic events should be associated with a specific context. Hippocampal dysfunction in experimentally stressed lab animals, and in humans with PTSD may cause traumatic memories to become overgeneralized.
* Dopamine is central to helping us form lasting memories for rewarding experiences. Like other neuromodulators, dopamine promotes plasticity, and its release tends to be concentrated in several brain areas that are important for helping us learn how to get rewards:
** Dopamine in the amygdala helps us learn about cues that signal an upcoming reward.
** In the hippocampus, it helps us learn about the contexts where we are likely to get rewards.
** in the nucleus accumbens, it helpus us learn what we need to do to get the reward.
* Over all, dopamine associates cues, contexts, and actions that lead to rewards and sets expectations that shape our experience when we get them.
* We are wired to learn only when the outcomes don't match up with our expectations.
* Sudden drops in dopamine activity drain motivation, while an increase in dopamine activity can be energizing.
* We often feel intensely motivated to seek out a reward even when we know it won't necessarily be pleasurable - cheating on a diet, smoking a cigarette when we have quit - this is the result of dopamine driving us.
* In gambling studies, when people unexpectedly won a bet, we saw a large neural response, but when they expected to win and did, we saw only a small neural response. if a person had a large neural response after seeing the outcome of the bet, they would be more likely to make the same bet next. The people who favored risky bets showed more activity in reward-learning circuits when they won than people who tended to play it safe. And unlike risk-averse subjects, risk-takers still got a bump of activity in the reward circuit even when they lost a risky bet. At least some people might have a reward-learning circuit that leads them to persist in making risky decisions even after bad outcomes.
* Cocaine, meth, heroin, opioids, and alcohol all activate the dopamine system, and can lead to powerful addictions.

== All Around Me Are Familiar Faces ==
* We tend to be more interested in exploring things that are new to us, than in things we have seen before.
* Electrical signals in the perirhinal cortex can artificially produce a sense of intense familiarity or novelty. This suggests that it might be responsible for that sense of familiarity we naturally experience when we visit a place or see a person we have seen before.
* The more activity in the perirhinal cortex when our volunteers read a word in the MRI scanner, the more familiar that word would seem when they saw it again on the surprise test. And, unlike with the hippocampus, activity in the perirhinal cortex was not related to people's ability to recollect the context of words that they had studied. Memories are not just strong of weak; rather the human brain has two different kinds of memory:
** Episodic memory, which is supported by the hippocampus
** Familiarity, which is supported by the perirhinal cortex.
* Cell assemblies all over the brain are in constant flux, reorganizing and optimizing so that the neural elections that determine our perceptions, thoughts, and actions will come to swift and decisive conclusions. When those tweaks happen in sensory areas, they help us read, see, and experience the world more efficiently. Those little tweaks also happen in higher-level areas of the brains, such as the perirhinal cortex, that integrate information from our different senses to help build semantic memories.
* All this neural plasticity seems to happen without our awareness, but the outcome can be sensed. the more familiar we become with something, the more our cell assemblies become fine-tune to recognize that thing later on. So, if we pay attention to how much mental effort we put in to read a word or recognize a face, we can get a sense of how much experience we have with it.
* When you initially think about a concept, such as a rambutan, activity spikes in the perirhinal cortex. It's as if this area of the brain is trying to match the word to a template you haven't yet created. In the aftermath of that encounter, the neural coalitions in this area get reorganized. The next time you think about rambutans, there's less activity because the election is resolved faster. The tweaking that happens after repeatedly seeing that word improves the brain's efficiency, reducing brain activity in the perirhinal cortex and making it easier to access the concept of rambutans.
* We often (mis)use familiarity as a heuristic, or mental shortcut, to guide decisions. Moreover, we can be blissfully unaware of these influences and instead reinforce our sense of free will by constructing stories that assign meaning to our choices and actions.
* Experience doesn't just change what you see, it changes what you look for. People tend to pay attention to the features that best distinguish faces of people from their own race, at the expense of features that help us recognize faces from other races.
* Like every other aspect of memory, familiarity has both a good and a bad side. It can be a useful by-product of how the brain is constantly becoming more efficient in its perceptions, but its slippery nature means that the fluency that results from mere exposure to something can operate under the radar of awareness, influencing our choices, judgments, and behavior. When we go on autopilot, familiarity can constrain our options and leave us with a smaller world.

== Turn and Face the Strange ==
* Memory's most important feature - orienting us to the future.
* Our memories of the past - "the old" - enable us to allocate critical resources to what is new and what has changed.
* Prediction errors initiate a cycle in the brain in which memory orients us to the unexpected, stimulating curiosity and motivating us to explore and resolve the gaps between our predictions and what we face in the present.
* Our eyes move about 4 times a second.
* When entering a space, we have:
** General knowledge (semantic memory) of what is supposed to be in a particular place.
** Familiarity - our eyes don't linger on things that are familiar, because we don't need to work as hard to process information about familiar objects, faces, or places.
* A major evolutionary function of the hippocampus is to tall us about places that are new or different, so we can explore and learn about these aread.
* Seeing something new or out of place should trigger a signal from the hippocampus stimulating us to explore out surroundings.
* Activity in the hippocampus increased when the subjects looked at pictures of new places.
* The brain's response to what is new is tightly coupled to our ability to remember what we have previously encountered, and that a loss of this novelty response may be an early indicator of risk for Alzheimer's disease.
* The hippocampus is critical for attuning our attention to changes in our environment.
* We might rely on these hippocampal memories to guide what to expect in the here and now. If something isn't in the right place, your spider-sense goes off, and your brain sends a signal to your eyes to scan that area so you can figure out what happened.
* Seeing the place was enough to trigger retrieval of a memory from the hippocampus.
* The hippocampus is one of the most evolutionary ancient structures in the brain.
* The orienting response, is an orchestration of changes in the brain and the body in response to something new or surprising. Our pupils enlarge, increasing sensitivity to light. Blood is pumped to the brain and constricted in the rest of the body, and the brain gets a brief shot of neuromodulators, such as dopamine, noradrenaline, and acetylcholine. There's also a coordinated changes in neural activity throughout a network of brain areas, including the hippocampus and the prefrontal cortex.
* The orienting response is probably one of the most reliable indicators of a functioning hippocampus.
* The hippocampus is like a "What is it?" detector, alerting the brain to something unexpected. It preferentially forms memories for the oddball images.
* Activity in the accumbens spiked about half a second after they saw the oddball image and the findings suggested that surprising or unexpected events can be sufficient to trigger activity in this system even when we do not get an external reward.
* Curiosity is triggered when we discover a discrepancy between what we know and what we'd like to know, a nebulous space "the information gap". Loewenstein proposed that curiosity is about the motivation to seek information, rather than the satisfaction of getting our questions answered. This drive is evolutionarily adaptive because it helps us maintain a balance between exploration (of the new) and exploitation (of the existing).
* By tapping into the reward circuitry, curiosity can enhance memory. This circuitry isn't about rewards, per se; it's about mobilizing us to learn and pursue anything we perceive to have value. And after food, water, and other basic needs are met, this means information.
* People have tendencies, conscious, or unconscious, about whether to respond to the unknown with curiosity or anxiety.

== Press Play and Record ==
* The catalyst for memory updating is the very act of remembering.
* Every time we recall an experience is one link in a neural chain subject to edits and updates, so that, over time, our memories can drift further and further from that initial event.
* We are especially vulnerable to misinformation at the moment of remembering.
* When we revisit a memory over and over, subtle alterations can creep in with each repetition. It's a bit like making a copy of a copy of a copy; the neural connections that hold together a memory are tweaked, and these changes can enlarge some aspects of the experience, while causing us to lose some of the details that keep the memory in focus. Like the fuzzy letters on my college band flyers, events from the distant past can seem more remote and blurry every time we call upon them, and noise becomes more prominent, corrupting the memory a bit more each time it's recalled.
* They made a painstakingly detailed computer model of hippocampus!
* Implanted memories, such as being lost in a mall are not entirely false; rather they are most likely imaginative constructions that incorporate information from schemas and details from real experiences.
* Memory is malleable, but it isn't mush.
* The sequence of steps in consolidation seems to happen whenever we retrieve a memory.
* We already know that memories can be strengthened, weakened, or modified from the moment they are pulled up. This kind of memory updating is at the heart of psychotherapy, which is fundamentally about changing connections that we made in the past in the face of new information. The goal isn't to erase someone's memories of what happened but to adaptively update memories and change one's relationship with the past by approaching it from a different perspective.

== Some Pain, More Gain ==

== When We Remember Together ==

[[Category:Consciousness]]
[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-20T10:12:05Z

Rob: /* Turn and Face the Strange */

== Where is My Mind? - The Neocortex ==

* By one estimate, the average American is exposed to 34GB (or 11.8hr) of information a day
* Hermann Ebbinghaus “On Memory: A contribution to Experimental Psychology (1885) - tried to memorize trigrams, established the idea of a forgetting curve over time.
* In essence, neurons function like a democracy with alliances or “cell assemblies”.
* Somewhere is the brain’s speech centers a large coalition of neurons cases votes for “bath”, a smaller coalition votes for “path”, and an even smaller minority votes for other candidates. Within less than half a second, the vote is tallied, and ultimately the baby picks up that it is time for a bath. The connections between the neutaons that supported bath are strengthened, and connections with neurons that voted for the wrong sound are weakened. As those neurons settle into coalitions that differentiate between the sound the baby is hearing, they are becoming less sensitive to sound differences that don’t exist in that language. It’s as if the neurons are choosing between a small number of candidates based on a few key issues.
* The connections in your brain are constantly being reshaped with the goal of improving your perception, movement, and thinking as you gain more and more experiences. Moreover, as you go past simple perception (what we see, hear, touch, taste, and smell) and move into higher-order functions (eg judgement, evaluation, and problem-solving), the brain is remarkably plastic, and the neural elections are highly contested.
* Interference - there is an intense competition between the coalition that has the memory you’re looking for and coalitions representing other memories you don’t need at that moment.
* The memories that are the most distinctive are the easiest to remember because they stand out relative to everything else.
* Attention - is our brain’s way of prioritizing what we are seeing, hearing, and thinking about.
* Intention - guide’s your attention to lock on to something specific.
* The prefrontal cortex:
** I the “central executive” of the brain. Several regions all over the brain have relatively specialized functions, and the job of the prefrontal cortex is to serve as a central executive, coordinating activity across these networks in the service of the mutual aim.
** Helps us learn with attention
** Takes up about a third of the real estate in the human brain
** Frontal lobotomy - removal of the prefrontal cortex - but rather than treating any underlying mental illness, it leaves patients in a zombielike state, apathetic, docile, and devoid of motivation.
** The more numbers people had to keep in mind, the more activity was apparent in the prefrontal cortex - it plays a part in temporarily holding information.
** People without a functioning prefrontal cortex could do fine when they were given clear instructions and no distractions, but they struggled when they had to spontaneously use memory strategies or follow through on a task when irrelevant things competed for their attention.
** Is intensively activated when a person had to use intention to stay on task, focus on distinctive information, resist distractions, or initiate some kind of mnemonic strategy.
** ADHD is associated with atypical activity in the prefrontal cortex.
** As we get older, we can still learn, but we have more trouble focusing on the details we want to take in and we often end up learning things that might be irrelevant.
** Certain part of the prefrontal cortex are thinned out, on average, in people who do heavy media multitasking.
* Use intention to guide our attention so we can remember what matters. Balance the needs of the experiencing self and the remembering self.

== Travelers of Time and Space - The Hippocampus ==
* We often think about memory as a record of what happened, but the human brain has the remarkable capability to link up the “what” with the where, when, and how. This explains why the experience of remembering is so often accompanied by an ephemeral sense of pastness that’s almost impossible to put into words. It’s also why, if we are in the right place at the right time, lost memories seem to find us.
* That sense of being in a particular time and place is called context, and it is critical for our day-to-day memory experiences. A great deal of everyday forgetting happens not because our memories have disappeared but because we can’t find our way back to them. In the right context, however, memories that have seemed long gone can suddenly resurface back to the forefront of our recall.
* Endel Tulving, in 1972, coined the term “episodic memory” to differentiate from “semantic memory”. To remember an event (episodic memory), we need to mentally return to a specific place and time; but to have knowledge (semantic memory), we need to be able to use what we previously learned across a range of contexts.
* For Tulving remembering puts us in a state of consciousness in which we feel as if we were transported to the past. A key characteristic of human consciousness is that we are “capable of mental time travel, roaming at will over what has happened as readily as over what might happen, independently of the physical laws that govern the universe.”
* You can confidently pull up facts about Paris (semantic memory) and vividly reexperience a trip to Paris (episodic memory), yet the two experiences are totally different.
* AIs have problems with “catastrophic forgetting”, where they learn a rule and then an exception to the rule makes them then throw away everything they had learnt around that rule to date. But we have episodic memory, which is not designed to capture the common elements of all our experiences; it stores and indexes every event differently, so you don’t get mixed up when you learn the exception to the rule.
* The neocortex works like a traditional neural network, enabling us to pick up facts, while the hippocampus is responsible for the brain’s amazing ability to rapidly create new memories for events.
* Brenda Milner, in 1957, published a paper about Patient H.M., Henry Molaison who had his seizures treated by removing about 5cm of tissue from the left and right hippocampus. Milner’s paper definitively linked the formation of new memories to the hippocampus.
* Ranganath suggested that the pattern of light and dark pixels identified by fMRI might be a unique configuration acting as a pointer to a particular memory like a QR code. When thinking about two separate episodic memories about the same person, the neocortex seemed to store the general facts about who and what were in the event, while in the hippocampus, the memory codes for the two related events looked totally different.
* The cell assemblies that allow us to remember particular parts of an event are in separate areas of the brain that normally do not talk to one another. The only thing they have in common is that they were active around the same time. The hippocampus, however, has connections to many of these areas, and its job is to store links to the different cell assemblies that come to life at a given moment. If you revisit the place, then the hippocampus would help reactivate all those cell assemblies, enabling you to reexperience seeing your friend. The hippocampus enables us to “index” memories for different events according to when and where they happened, not according to what happened. Because it organizes memories according to the context, recalling something from one event makes it easier to retrieve other events that happened around the same time or place, painting a fuller picture.
* Pulling up a memory of the recent past helps to ground you in the here and now. According to one prominent theory, episodic memory emerged in evolution from the more basic ability to learn where we are in the world.
* Sea lions without a functioning hippocampus grow disoriented. Lost, and unable to recall their foraging sites, they become malnourished and ultimately stranded onshore.
* The hippocampus is one of the first areas of the brain ravaged by Alzheimer’s, and this is probably why patients in the early stages frequently get lost and lost track of the passage of time. You see the look of fear on a face when a patient becomes unmoored from their sense of when and where they are in the world, like treading water in the open ocean.
* All the external factors from our environment, along with the motivations, thoughts, and feelings that characterize our internal world, come together to form the unique context that envelops our experience at any given time. When we access a particular episodic memory, we can pull up a bit of that past mental state, too.
* Two events that occurred close together in time are going to have more contextual elements in common than events that occurred further apart in time.
* Place, smells, tastes, and music are all powerful cues for episodic memories.
* Our emotions also contribute to context, which means that our feelings in the present affect what we can recall from the past. When we get angry, it’s easy to pull up all those memories that give us more reasons to be annoyed, and it’s harder to access the memories that don’t.
* The essential trick performed by the hippocampus is that it takes in information about the things in which we are interested, and it ties it up with information about the context, all the other stuff that’s going on in the background. We experience zillions of repetitive events, but the context makes each unique, and we can use context as a lifeline to find our way back to those things we seem to always lose.
* The further back in time you try to go, the harder it is for your brain to pull up a past context, and in some cases you won’t be able to do it. Science backs infantile amnesia where you can’t have episode memories before the age of two because the hippocampus is still developing and the entire neocortex is being massively reorganized.
* Event boundaries. We naturally update our sense of context when we experience a shift in our perception of the world around us, and those points mark the boundary between one event and another. People are better at remembering information that occurred at an event boundary then they are at remembering information from the middle of the event, and this is because the hippocampus waits to store a memory for an event until right after an event boundary - so we only encode the memory once we have a full understanding of the event.
** Event boundaries happen all the time and don’t necessarily require a change in location. Anything that alters your sense of the current context - a shift in the topic of conversation, a change in your immediate goals, or the onset of something surprising - can lead you to put up an event boundary.
* During the Covid epidemic, confined to home and with few event boundaries to provide meaningful structure to their lives, millions of people all over the world felt as if they were living in the twilight zone, floating aimlessly through time and space.
* Nostalgia - on average, people find it easier to recall positive experiences than negative ones, and this positivity bias increases as we get older, which might explain older adults’ penchant for nostalgia.
** The reminiscence bump - when we look back at the past, we tend to focus on a specific period of our lives, between the ages of ten and thirty - something about listing to a song or watching a movie from those formative years can give us a sense of meaning, connecting us to an idealized sense of who we are.
** The cost of nostalgia is that it can leave us feeling disconnected from our lives in the present, giving us a sense that things aren’t as they were in the “good old days”.
* Rumination - is the evil twin of nostalgia, and a prime example of how not to use episodic memory.

== Reduce, Reuse, Recycle - Schemas and the Default Mode Network (DMN) ==
* We can keep up to only 3-4 pieces of information in mind at once, but there is a huge loophole: there is no set definition for what constitutes one piece of information. Chunking allows us to compress massive amounts of data into a manageable amount of information that is easily accessible.
* Like memory athletes, chess grand masters use a combination of skill, training, and experience - aka expertise - to chunk at lightning speed. Expertise changes the way we mobilize the prefrontal cortex. Experts develop particular ways to extract the most useful information about what they are trying to remember, allowing them to bypass the limitations of memory by leveraging their expertise.
* Expertise isn't just about seeing patterns, it's about the way we find them. As we gain expertise in any topic, we can exploit what we have learned to focus on the most important bits of new information that we need.
* The human brain is not a memorization machine; it's a thinking machine.
* A schema is a kind of mental framework that allows our minds to process, organize, and interpret a great deal of information with minimal effort. A schema is like a blueprint for a space or an event. Event schemas provide the structure that allows us to rapidly form memories for a complex event. They are like scripts for ordering coffee, meeting a colleague, going to the cinema, etc.
* In some way or another, every expert exploits the power of schemas to organize what they need to remember into a framework they can access later.
* The Default Mode Network (DMN) is a set of neocortical areas that consume the most energy in the brain, yet activity in these areas seems to go down when people are focusing their attention on some arbitrary task. Brain activity in the hippocampus is tightly linked with what is going on in the DMN. It seems that cell assemblies in the DMN store the schemas we use to understand the world, dissecting the events we experience into pieces so that we can use them in new ways to construct new memories. The hippocampus could, in turn, put the pieces together to store a specific episodic memory.
* In an experiment about watching and recounting the plots of movies:
** The DMN was providing the raw materials needed to understand and remember each movie, but it was not storing context-specific episodic memories. Instead of storing a unique memory code for each movie, the DMN was breaking up each movie into components that were repeatedly reused to understand or remember other movies that shared the same components. Memory codes in one part of the DMN could tell us whether the subject was watching or remembering a movie that took place in a supermarket or a café, whereas memory codes in a different part of the DMN could tell us whether A or B was the star in the movie.
** In contrast to the DMN, the hippocampus, which supports episodic memory by putting together information from all over the brain - did have a separate memory code for each movie. And unlike the DMN, the hippocampus only seemed to store a memory for the beginning and end of each movie (ie, the event boundaries).
** Thanks to the DMN, I can reuse my supermarket schema every time I shop for groceries, and I can reuse my A schema every time I see A. And thanks to the hippocampus, I can also form different memories for every specific occasion that I run into A at the supermarket.
* Forming an episodic memory is a bit like building with LEGOs, breaking down models and using the independent components again and again in different contexts.
* It's now clear that amyloid - a protein implicated in the development of Alzheimer's disease - accumulates in the DMN in about 20% of older adults long before any symptoms are apparent.
* A chess grand master has a library of chess game schemas, each containing templates for entire sequences of moves you typically see in a game. Those schemas allow them to remember sequences of moves in past games, to understand what is happening in a game in real time, and to predict likely moves that an opponent could make in the future. By exploiting that expert knowledge, a seemingly complex configuration of pieces can easily be understood as one step in a series of moves that might wipe out a number of pieces and lead to a checkmate.
* Schemas allow us to see through an event, capturing the deeper structures of how everything is connected. In doing so, we can compress memories of hundreds, even thousands, of experiences into a format that enables us to make inferences and predictions about events we haven't yet experienced. Schemas allow us to use knowledge about what has happened to get a head start on what will happen.

== Just My Imagination ==
* Shereshevsky - the capacity of his memory had no distinct limits.
* He may have had synesthesia - every stimulus, regardless of which sense it came through, triggered every other sense. He could taste words, see music and smell colors.
* The connection between the worlds he created in his mind and the world he lived in was so visceral that he could elevate his hear rate by simply imagining he was running for a train. He could raise the temperature of one hand and lower the other by picturing one hand on a stove and the other resting on a block of ice.
* The brain activity changes that occur when people imagine these kinds of scenarios are remarkably similar to those that occur when people recall events that they actually experienced.
* "Remembering is not the re-excitation of innumerable fixed, lifeless and fragmentary traces. It is an imaginative reconstruction." We do not simply replay a past event, but use a small amount of context and retrieved information as a starting point to imagine how the past could have been. We put together a story on the fly, based on our personal and cultural experiences, and tack on those retrieved details to flesh out the story. Bartlett's insight is key to understanding why the brain's machinery for imagination and for memory aren't completely independent - they are both based on pulling up knowledge about what can happen, though not necessarily what did happen.
* The hippocampus might get us back to some of the cell assemblies that were active during some moments in a conversation, but we still need to use schemas in the default network to make sense of what we are pulling up. this reconstruction is prone to error, however, because schemas capture what typically happens, not what did happen.
* Our minds are constantly churning with what-ifs. We conjure up scenarios for what could happen in the future, and we wonder what our present would be like if past events had turned out differently. All the scenarios we imagine leave us with memories of events we have never experienced, and our memories don't come with labels certifying them as imagined or real.
* So we need reality monitoring. The more sensory details that come to mind when you remember an event, the more likely it is that it really happened, because on average what we imagine is not as detailed as what we have experienced.
* We can counteract the fallibility of memory by considering not only the quality of the details that seem to put us back in a specific place and time but also the likelihood that those details could have been constructed to create an alternative reality. As with all critical thinking, it helps to remain skeptical until presented with further evidence.
* Monitoring the details of our memories engages the most evolutionarily advanced areas of the human prefrontal cortex.
* Confabulation: Some people who have extensive damage to the prefrontal cortex can confidently recall things that never happened. We all are guilty of minor confabulations. When we're tired or stressed out, or when our attention is divided by multitasking, reality monitoring goes out the window. As we get older, prefrontal function gets words, and we find it harder to tell the difference between imagination and experience.
* In 1928, Bartlett speculated that creative works are constructed by essentially doing the opposite of reality monitoring - that is, by pulling up fragments of memories and then assembling those bits and pieces into a cohesive product of imagination.
* The hippocampus and the DMN might function at the crossroads between memory and imagination by allowing us to extract the ingredients from past experiences and recombine them into new creations.
* AI art is not about generating something new, it's about taking elements from preexisting human art and recombining them (based on human direction and curation).
* We now know that it is in that space where memory meets imagination that we interpret reality and create our greatest treasures.

== More Than a Feeling - the Amygdala ==
* Our emotions, as well as the actions and choices they influence, are shaped by basic survival circuits in the brain that motivate us to avoid threats, find sustenance, and reproduce. When these circuits go into overdrive, we tend to experience intense emotions, such as elation, lust, panic, anxiety, or disgust. These are experiences we remember most vividly, because they provide valuable information that we can use in the future to stay safe, thrive, and reproduce.
* Neuromodulators promote plasticity, enabling long-lasting changes in the connections between neurons in the cell assemblies that are activated when we learn something new.
* Noradrenaline (AKA norepinephrine) is released all over the brain in response to threats. Emotional arousal changes what we will remember, rather than simply how much. If you get mugged your attention will be on the weapon pointed at you rather than the mugger's shoes. It's easy to forget more mundane experiences, but hard to let go of a traumatic memory: our brains are designed to hold on to the events that revved us up, ostensibly because remembering those events has survival value.
* When we recall a time our survival circuits were called into action, the hippocampus works with the amygdala. As the hippocampus forms memories that capture the context at that moment, the amygdala is connecting those memories with the survival circuits that generate the raw sensations. Later on, when remembering, the amygdala brings us back to the heat of the moment, making us feel as if we are vividly reexperiencing the event.
* We feel anxious when we think something bad might happen, but we cannot predict or control whether it will happen.
* Cortisol spikes when you are stressed out to improve your ability to retain memories for what happened right before or after the stressful event. Like noradrenaline, stress hormones seem to promote plasticity, initiating the cascade of changes that consolidate connections within the cell assemblies representing the memory for a stressful event.
* Stress tips the chemical balance in the brain, downregulating the executive functions mediated by the prefrontal cortex and enhancing the sensitivity of the amygdala.
* In the healthy brain, if the hippocampus does its job, then memories for traumatic events should be associated with a specific context. Hippocampal dysfunction in experimentally stressed lab animals, and in humans with PTSD may cause traumatic memories to become overgeneralized.
* Dopamine is central to helping us form lasting memories for rewarding experiences. Like other neuromodulators, dopamine promotes plasticity, and its release tends to be concentrated in several brain areas that are important for helping us learn how to get rewards:
** Dopamine in the amygdala helps us learn about cues that signal an upcoming reward.
** In the hippocampus, it helps us learn about the contexts where we are likely to get rewards.
** in the nucleus accumbens, it helpus us learn what we need to do to get the reward.
* Over all, dopamine associates cues, contexts, and actions that lead to rewards and sets expectations that shape our experience when we get them.
* We are wired to learn only when the outcomes don't match up with our expectations.
* Sudden drops in dopamine activity drain motivation, while an increase in dopamine activity can be energizing.
* We often feel intensely motivated to seek out a reward even when we know it won't necessarily be pleasurable - cheating on a diet, smoking a cigarette when we have quit - this is the result of dopamine driving us.
* In gambling studies, when people unexpectedly won a bet, we saw a large neural response, but when they expected to win and did, we saw only a small neural response. if a person had a large neural response after seeing the outcome of the bet, they would be more likely to make the same bet next. The people who favored risky bets showed more activity in reward-learning circuits when they won than people who tended to play it safe. And unlike risk-averse subjects, risk-takers still got a bump of activity in the reward circuit even when they lost a risky bet. At least some people might have a reward-learning circuit that leads them to persist in making risky decisions even after bad outcomes.
* Cocaine, meth, heroin, opioids, and alcohol all activate the dopamine system, and can lead to powerful addictions.

== All Around Me Are Familiar Faces ==
* We tend to be more interested in exploring things that are new to us, than in things we have seen before.
* Electrical signals in the perirhinal cortex can artificially produce a sense of intense familiarity or novelty. This suggests that it might be responsible for that sense of familiarity we naturally experience when we visit a place or see a person we have seen before.
* The more activity in the perirhinal cortex when our volunteers read a word in the MRI scanner, the more familiar that word would seem when they saw it again on the surprise test. And, unlike with the hippocampus, activity in the perirhinal cortex was not related to people's ability to recollect the context of words that they had studied. Memories are not just strong of weak; rather the human brain has two different kinds of memory:
** Episodic memory, which is supported by the hippocampus
** Familiarity, which is supported by the perirhinal cortex.
* Cell assemblies all over the brain are in constant flux, reorganizing and optimizing so that the neural elections that determine our perceptions, thoughts, and actions will come to swift and decisive conclusions. When those tweaks happen in sensory areas, they help us read, see, and experience the world more efficiently. Those little tweaks also happen in higher-level areas of the brains, such as the perirhinal cortex, that integrate information from our different senses to help build semantic memories.
* All this neural plasticity seems to happen without our awareness, but the outcome can be sensed. the more familiar we become with something, the more our cell assemblies become fine-tune to recognize that thing later on. So, if we pay attention to how much mental effort we put in to read a word or recognize a face, we can get a sense of how much experience we have with it.
* When you initially think about a concept, such as a rambutan, activity spikes in the perirhinal cortex. It's as if this area of the brain is trying to match the word to a template you haven't yet created. In the aftermath of that encounter, the neural coalitions in this area get reorganized. The next time you think about rambutans, there's less activity because the election is resolved faster. The tweaking that happens after repeatedly seeing that word improves the brain's efficiency, reducing brain activity in the perirhinal cortex and making it easier to access the concept of rambutans.
* We often (mis)use familiarity as a heuristic, or mental shortcut, to guide decisions. Moreover, we can be blissfully unaware of these influences and instead reinforce our sense of free will by constructing stories that assign meaning to our choices and actions.
* Experience doesn't just change what you see, it changes what you look for. People tend to pay attention to the features that best distinguish faces of people from their own race, at the expense of features that help us recognize faces from other races.
* Like every other aspect of memory, familiarity has both a good and a bad side. It can be a useful by-product of how the brain is constantly becoming more efficient in its perceptions, but its slippery nature means that the fluency that results from mere exposure to something can operate under the radar of awareness, influencing our choices, judgments, and behavior. When we go on autopilot, familiarity can constrain our options and leave us with a smaller world.

== Turn and Face the Strange ==
* Memory's most important feature - orienting us to the future.
* Our memories of the past - "the old" - enable us to allocate critical resources to what is new and what has changed.
* Prediction errors initiate a cycle in the brain in which memory orients us to the unexpected, stimulating curiosity and motivating us to explore and resolve the gaps between our predictions and what we face in the present.
* Our eyes move about 4 times a second.
* When entering a space, we have:
** General knowledge (semantic memory) of what is supposed to be in a particular place.
** Familiarity - our eyes don't linger on things that are familiar, because we don't need to work as hard to process information about familiar objects, faces, or places.
* A major evolutionary function of the hippocampus is to tall us about places that are new or different, so we can explore and learn about these aread.
* Seeing something new or out of place should trigger a signal from the hippocampus stimulating us to explore out surroundings.
* Activity in the hippocampus increased when the subjects looked at pictures of new places.
* The brain's response to what is new is tightly coupled to our ability to remember what we have previously encountered, and that a loss of this novelty response may be an early indicator of risk for Alzheimer's disease.
* The hippocampus is critical for attuning our attention to changes in our environment.
* We might rely on these hippocampal memories to guide what to expect in the here and now. If something isn't in the right place, your spider-sense goes off, and your brain sends a signal to your eyes to scan that area so you can figure out what happened.
* Seeing the place was enough to trigger retrieval of a memory from the hippocampus.
* The hippocampus is one of the most evolutionary ancient structures in the brain.
* The orienting response, is an orchestration of changes in the brain and the body in response to something new or surprising. Our pupils enlarge, increasing sensitivity to light. Blood is pumped to the brain and constricted in the rest of the body, and the brain gets a brief shot of neuromodulators, such as dopamine, noradrenaline, and acetylcholine. There's also a coordinated changes in neural activity throughout a network of brain areas, including the hippocampus and the prefrontal cortex.
* The orienting response is probably one of the most reliable indicators of a functioning hippocampus.
* The hippocampus is like a "What is it?" detector, alerting the brain to something unexpected. It preferentially forms memories for the oddball images.
* Activity in the accumbens spiked about half a second after they saw the oddball image and the findings suggested that surprising or unexpected events can be sufficient to trigger activity in this system even when we do not get an external reward.
* Curiosity is triggered when we discover a discrepancy between what we know and what we'd like to know, a nebulous space "the information gap". Loewenstein proposed that curiosity is about the motivation to seek information, rather than the satisfaction of getting our questions answered. This drive is evolutionarily adaptive because it helps us maintain a balance between exploration (of the new) and exploitation (of the existing).
* By tapping into the reward circuitry, curiosity can enhance memory. This circuitry isn't about rewards, per se; it's about mobilizing us to learn and pursue anything we perceive to have value. And after food, water, and other basic needs are met, this means information.
* People have tendencies, conscious, or unconscious, about whether to respond to the unknown with curiosity or anxiety.

== Press Play and Record ==

== Some Pain, More Gain ==

== When We Remember Together ==

[[Category:Consciousness]]
[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-20T09:47:06Z

Rob: /* More Than a Feeling - the Amygdala */

From Bacteria to Bach and Back

2025-04-16T13:27:49Z

Rob: /* 15. The Age of Post-Intelligent Design */

== Part I: Turning Our World Upside Down ==
=== 1. Introduction ===
* How come there are minds?
** Minds evolved and created thinking tools that eventually enabled minds to know how minds evolved, and even to know how these tools enabled them to know what minds are.
** What thinking tools? The simplest, on which all the others depend in various ways, are spoken words, followed by reading, writing, and arithmetic, followed by navigation and mapmaking, apprenticeship practices, and all the concrete devices for extracting and manipulating information that we have invented: compass, telescope, microscope, camera, computer, the Internet, and so on.
** These, in turn, fill our lives with technology and science, permitting us to know many things not known by other species. We know there are bacteria. Even bacteria don't know there are bacteria.
** Our minds are different. It takes thinking tools to understand what bacteria are, and we're the only species (so far) endowed with an elaborate kit of thinking tools.
* A birds-eye view of the journey:
** Life has been around on Earth for around 4bn years. The first 2bn were spent optimizing the machinery for self-maintenance, energy acquisition and reproduction, and the only living things were relatively simple, single-celled entities - bacteria or their cousins, archaea: the prokaryotes.
** Then an amazing thing happened. Two different prokaryotes collided and instead of one eating the other, it let it go on living, and, by dumb luck, found itself fitter, more competent in some way that mattered, than it had been before. This was perhaps the first successful instance of technology transfer. A fortuitous mutation almost never happens, but evolution depends on those rarest of rare events. This is the birth of the eukaryotes
** Every living thing big enough to be visible to the naked eye is a multicellular eukaryote.
** The Cambrian Explosion, which occurred over several million years about 530m ya, saw the sudden arrival of a bounty of new life forms.
** The "MacCready Explosion", at the dawn of human agriculture, about 10k ya, transformed the terrestrial vertebrate biomass (excluding insects, other invertebrates, and marine animals). At the beginning, humans plus their livestock and pets make up only 0.1%, and now we make up 98% (mostly cattle). This explosion is based on three factors - population, technology, and intelligence (our so-called native intelligence depends on both our technology and our population numbers).
* Dennett identified the "romantic" and "killjoy" sides of the duel over the stature of animal minds. We are not the God-like geniuses we think we are, but animals are not so smart either, and yet both humans and other animals are admirably equipped to deal "brilliantly" with many of the challenges thrown at them.

=== 2. Before Bacteria and Bach ===
* until there were systems that could be strictly called reproducing systems, the processes at work were only proto-evolutionary, semi-Darwinian, partial analogues of proper evolution by natural selection; they were processes that raised the likelihood that various combinations of ingredients would arise and persist, concentrating the feedstock molecules until this eventually led to the origin of life.
* A living thing must capture enough energy and materials, and fend off its own destruction long enough to construct a good enough replica of itself.
* The reverse-engineering perspective is ubiquitous in biology and is obligatory in investigations of the origin of life. It always involves some kind of optimality considerations: What is the simplest chemical structure that could possibly do x? Or would phenomenon x be stable enough to sustain process y?
* Orgel's second rule: "Evolution is cleverer than you are."
* Here is an example of a possible gambit in the origin of life:
** It is tempting to assume that the very first living thing capable of reproducing must have been the simples possible living thing (given the existing conditions on the planet at the time).
** Make the simples replicator you can imagine and then build on that foundation.
** But this is by no means necessary. It is possible, and more likely, I think, that a rather inelegantly complicated, expensive, slow, Rub-Goldberg conglomeration of objets trouvés was the first real replicator, and after it got the replication ball rolling, this ungainly replicator was repeatedly simplified in competition with its kin.
** Many of the most baffling magic tricks depend on the audience no imagining the ridiculously extravagant lengths magicians will go to in order to achieve a baffling effect. If you want to reverse-engineer magicians, you should always remind yourself that they have no shame, no abhorrence of bizarre expenditures for tiny effects that they can then exploit. Nature, similarly, has no shame - and no budget, and all the time in the world.
* [[Adaptionism]] is alive and well; reverse-engineering is still the royal road to discovery in biology.

=== 3. On the Origin of Reasons ===
* There are three strategies to adopt when trying to understand, explain, and predict phenomena:
** The physical stance - is the least risky but also the most difficult; you treat the phenomenon as obeying the laws of physics, and use physics to predict what will happen next.
** The design stance - is only for things that have been designed, either artifacts or living things or their parts, and have functions or purposes.
** The intentional stance - works primarily for things that are designed to use information to accomplish their functions. It works by treating the thing as a rational agent, attributing "beliefs" and "desires" and "rationality" to the thing, and predicting that it will act rationally.
* Evolution by natural selection is not itself a designed thing, an agent with purposes, but it acts as if it were. It is a set of processes that "find" and "track" reasons for things to be arranged one way rather than another.
* The reasons found by human designers are typically (but not always) represented in the minds of the designers, whereas the reasons uncovered by natural selection are represented for the first time by those human investigators who succeed in reverse-engineering Nature's productions.
* Our human world of reasons grew out of a world where there were no reasons.
* Two meanings of the word "why":
** What for - "Why are you handing me your camera?"
** How come - "Why does ice float?" This is asking for a cause or a process narrative
* Evolution by natural selection starts with "how come" and arrives at "what for". We start with a lifeless world in which there are no reasons, no purposes at all, but there are processes that happen.
* A central feature of human interaction, and one of the features unique to our species, is the activity of asking others to explain themselves, to justify their choices and actions, and then judging, endorsing, rebutting their answers, in recursive rounds of the "why?" game.
* Our capacity to respond appropriately in this reason-checking activity is the root of responsibility. Those who cannot explain themselves or cannot be moved by the reasons offered by others, those who are "dead to" the persuasions of advisors, are rightly judges to be of diminished responsibility and are treated differently by the law.
* The "logical space of reasons" is bound by norms, by mutual recognition of how things ought to go. Wherever there are reasons, there is room and need for some kind of justification and the possibility of correction when something goes wrong. This normativity is the foundation of ethics.
* But there are two kinds of norms and corrections:
** social normativity - concerned with social norms, practice, and collaboration
** instrumental normativity - concerned with quality control or efficiency, the norms of engineering
* Natural selection is an algorithmic process, a collection of sorting algorithms that are themselves composed of generate-and-test algorithms.
* In the prebiotic or abiotic world (before life), there were cycles at many spatio-temporal scales: seasons, night and day, tides, the water cycle, and thousands of chemical cycles discoverable at the atomic and molecular level, gradually changing the conditions in the world and thus raising the probability that something new will happen.
* This led to differential persistence, some temporary combinations of parts hang around longer than others. The rich can get richer, even though they can't yet bequeath their riches to descendants.
* Differential persistence must then somehow gradually turn into differential reproduction.
* "Serendipity" is when something good happens randomly, while "clobbering" is when something bad happens randomly.
* Walls or membranes that are randomly persisted are serendipitous in that they allow internal cycles to operate for a time without interference, and we see the engineering necessity of membranes to house the collection of chemical cycles - the Krebs cycle and thousands of others - that together permit life to emerge.
* Before we can have competent reproducers, we have to have competetent persisters. We are witnessing an automatic (algorithmic) paring away of the nonfunctional, crowded out by the functional.
* There are reasons why the parts are shaped and ordered as they are and this is the birth of reasons. Through Darwinism about Darwinism, we see the gradual emergence of the species of reasons out of the species of mere causes, what fors out of how comes*
* Natural selection is an automatic reason-finders, which "discovers" and "endorses" and "focuses" reasons over many generations.
* If there happens to be a "difference that happens to make a difference" then we have the germ of a reason, a proto-reason, and when this is selected to persist longer, then we can see emerge the accumulation of function by a process that blindly tracks reasons.
* Reasons existed before there were reasoners. There are reasons why trees spread their branches but they are not, in any strong sense, the trees' reasons. They don't "have" the reasons and they don't need to have the reasons.
* Darwin didn't extinguish teleology - he naturalized it.
* Reverse-engineering in biology is a descendant of reason-giving-judging.
* The evolution of what for from how come can be seen in the way we interpret the gradual emergence of living things via a cascade of prebiotic cycles. Free-floating rationales emerge as the reasons why some features exist; they do not presuppose intelligent designers, even though the designs that emerge are extraordinarily good.

=== 4. The Strange Inversions of Meaning ===
* The world before Darwin was held together not by science but by tradition, through the trickle-down theory of creation from God, which Darwin replaced by the bubble-up theory of creation.
* Design space:
** Skyhooks - float high in design space, unsupported by ancestors, the direct result of a special act of intelligent creation.
** Cranes - are non-miraculous innovations in design space that enable ever more powerful lifting and efficient exploration of the space. Endosymbiosis is a crane, as are sex and language and culture.
* Turing showed that it was possible to design mindless machines that were absolutely ignorant, but that could do arithmetic perfectly, following "instructions" that could be mechanically implemented.
* This is "competence without comprehension" and Turing saw that it could provide a traversable path in design space from absolute ignorance to artificial intelligence.
* All the brilliance and comprehension in the world arises ultimately out of uncomprehending competences compounded over time into ever more competent - and hence comprehending - systems.
* This overthrows the pre-Darwinian mind-first vision of Creation with a mind-last vision.
* Darwin discovered evolution by natural selection, while Turing invented the computer, but he is one of the twigs on the Tree of Life who is, himself, an indirect product of the blind Darwinian processes.
* Distribution of expertise or understanding of this sort is a hallmark of human creative processes.
* "Ontology" is the set of "things" that an animal can recognize and behave appropriately with regard to, and equally the set of things that a computer program has to be able to deal with to do its job. Humans have extremely varied ontologies. Some believe in electrons and some believe in abominable snowmen, but there is a huge common core that is shared by all normal human beings from around 6 years old:
** Manifest image - the things we use in our daily lives to anchor our interactions and conversations. For every noun in our everyday speech, there is a kind of thing it refers to. It comes along with your native language. It's the world according to us
** Scientific image - populated with molecules, atoms, electrons, gravity, quarks. But even scientists spend most of their day in the manifest image.
* These two versions of the world that are now quite distinct were once merged or intertwined in a single ancestral world of "what everybody knows" that included all the local fauna and flora and weapons and tools and dwellings and social roles, but also goblins and gods and miasmas and spells.
* We can treat animals as having different ontologies without settling issues of whether they are conscious of them or simply the beneficiaries of designs that can be interpreted (by reverse engineers or forward engineers) as having those ontologies.
* A well designed elevator:
** Has a kind of ontology. It is a good elevator if it interacts appropriately with its environment and its passengers. It uses variables to keep track of all the features of the world that matter to getting its job done and is oblivious to everything else.
** It has no need to know what its ontology is or why - the rationale of the program is something only the program's designers have to understand.
** Its prudent self-monitoring can be seen to be an elementary step towards consciousness.
* Even bacteria are good at staying alive, at making the right moves at the right times, but they have elevator-type minds, not elevated minds like ours. And these minds are the products of an R&D process of trial and error that gradually structured their internal machinery to move from state to state in a way highly likely - not guaranteed - to serve their limited but vital interests.
* But unlike the elevator there is noting at all that plays the rols of the labels or comments in a source program. There is nothing anywhere at any time in that R1D history that represents the rationales of it. But they can be discovered by reverse engineering - there is a reason why the parts are shaped as they are, why the behaviors are organized as they are, and that reason will "justify" the design (or an earlier design that has now become either vestigial or transformed by further evolution to serve some newer function.
* The elevator has replaced a human - the elevator operator - by a machine that "sorta" follows the same rules as the human. We humans often occupy this kind of intermediate level of consciousness where we have internalized or routinized through practice a set of explicit rules that we may then discard and even forget.
* The Manhattan project had a small number of intelligent designers who organized a massive group of people, most of whom knew nothing about what they were doing beyond their immediate tasks. The "need to know" principle means that it is possible to create very reliable levels of high competence with almost no comprehension for rather insulated tasks
* GOFAI can be seen in retrospect as an exercise in creating something rather Cartesian, a rationalistic expert with myriads of propositions stored in its memory, and all the understanding incorporated in its ability to draw conclusion. It relied on the comprehension of the designers to contrive systems composed of subsystems that were foresightedly equipped with exactly the competences they would need in order to handle the problems they might face.
* But modern deep-learning AI is bottom-up, using wasteful, mindless, less bureaucratic, more evolution-like processes of information extraction.
* Top-down intelligent designing works, but it is responsible for much less of the design in our world than is commonly appreciated.
* Comprehension, far from being a Godlike talent from which all design must flow, is an emergent effect of systems of uncomprehending competence; natural selection on one hand, and mindless computation on the other.

=== 5. The Evolution of Understanding ===
* Human designers start with a goal (which may be refined or abandoned along the way) and work top-down, with the designers using everything they know to guide their search for solutions to the design problems they set for themselves.
* Evolution, in contrast, has no goals, no predefined problems, and no comprehension to bring to the task.
* How could a slow, mindless process build a thing that could build a thing that a slow mindless process couldn't build on its own? A process with no Intelligent Designer can create intelligent designers who then design things that permit us to understand how a process with no Intelligent Designer can create intelligent designers who then design those things.
* An organism's "umwelt" is the behavioral environment that consists of all the things that matter to its well-being.
* "Affordances" are the relevant opportunities in the environment of any organism: things to eat of mate with, openings to walk through or look out of, holes to hide in, things to stand on, and so forth.
* Organsims can be the beneficiaries of design features that imply ontologies without themselves representing those ontologies.
* Biology is reverse-engineering, and reverse-engineering is methodically committed to optimality considerations. Bacteria don't know they are bacteria, but they respond to other bacteria in bacteria-appropriate ways and are capable of avoiding or tracking or trailing things they distinguish in their umwelt.
* In software engineering, there is a reason why debugging cannot be completely automated: what counts as a bug depends on all the purposes (and sub and sub-sub-purposes) of the software, and specifying in sufficient detail what those purposes are is, at least for practical purposes, the very same task as writing debugged code in the first place!
* Design revision in Nature must follow the profligate method of releasing and test-driving many variants and letting the losers die, unexamined.
* Evolution explores the "adjacent possible".
* Natural selection is full of bugs. Organisms are filled with all-but-undecipherable "spaghettit code" of undisciplined programmers, but the free-floating rationale of the whole system is clearly good enough for practical purposes.
* When does comprehension emerge?
* We are right to adopt the intentional stance to understand the benefits derived from competences, but these competences can be provided by the machinery without any mentality intruding at all.
* We can say that organisms with spectacular competences but without comprehension, are "gifted".
* When there isn't enough stability over time in the selective environment to permit natural selection to "predict" the future accurately (when "selecting" the best designs for the next generation), natural selection does better by leaving the next generation's design partially unfixed. Learning can take over where natural selection left off, optimizing the individuals in their own lifetimes by extracting information from the world encountered and using it to make local improvements.
* Costly-signalling theory, where an animal does something to deceive or distract a predator does not need comprehension. These animals cannot choose to deceive, they simply do it automatically in certain circumstances due to a "knee-jerk reflex".
* Comprehension is not the source of competence or the active ingrediant in competence - instead, it is composed of competences.
* The illusion that understanding is some additional, separable mental phenomenon is fostered by the aha! phenomenon, or eureka effect.
* Comprehension comes in degrees, but even at the highest levels of competence, comprehension is never absolute. All comprehension is sorta comprehension from some perspective.
* We count on experts to have deep "complete" understanding of difficult concepts we rely on every day, only half-comprehendingly, and language is the capacity to transmit, faithfully, information we only sorta understand.
* The Beatrix Potter syndrome, or intentional stance towards animals works whether the rationales it adduces are free floating or explicitly represented in the midst of the agents we are predicting.
* Whatever is going on in the animal's brain has the competence to detect and respond appropriately to the information in the environment. But the intentional stance just gives the specs for the mind and leaves the implementation for later.
* We idealize everybody's thinking, and even our own access to reasons, blithely attributing phantom bouts of clever reasoning to ourselves after the fact. Asked "Why did you do that?", the most honest thing to say is often "I don't know, it just came to me," but we often succumb to the temptation to engage in whig history, not settling for how come but going for what for.
* Four grades of competence:
** Darwininian Creatures - Have predefined and fixed competences created by the R&D of evolution. They are born hard-wired, knowing all they will ever know, they are gifted but not learners.
** Skinnerian Creatures - Have, in addition, the ability to adjust their behavior in reaction to "reinforcement". They start out with some "plasticity". They more or less randomly generate new behaviors to test the world and those that get reinforced are more likely to recur in similar circumstances in the future.
** Popperian Creatures - Look before they leap. They extract information about the cruel world and keep it handy, so they can use it to pretest hypothetical behaviors offline. Eventually they must act in the real world, but their first choice is not random, having won the generate-and-test competition trial runs in the internal environment model. The "habit" of "creating forward models" of the world and using them to make decision and modulate behavior is a fine habit to have, whether or not you understand it.
** Gregorian Creatures - Their Umwelt is well stocked with thinking tools, both abstract and concrete. Only with them do we find the deliberate introduction and use of thinking tools, systematic exploration of possible solutions to problems, and attempts at higher-order control of mental searches. Only we human beings are Gregorian creatures, apparently.
* The smartest animals are not "just" Skinnerian creatures but Popperian creatures, capable of figuring out some of the clever things they have been observed to do. They engage in exploratory behavior. They need not know that this is the rationale for their behavior, but they benefit from it by reducing uncertainty. The fact that they don't understand the grounds of their own understanding is no barrier to calling it understanding, since we humans are often in the same ignorant state about how we manage to figure out novel things.
* Some animals, like us, have something like an inner workshop, a portable design-improvement facility.
* An unconscious mind is no longer seen as a contradiction in terms. The puzzle today is what is consciousness for (if anything)?
* Animals, plants, and even microorganisms are equipped with competences that permit them to deal appropriately with the affordances of their environments. There are free-floating rationales for all these competences, but the organisms need not appreciate or comprehend them to benefit from them, nor do they need to be conscious of them. In animals with more complex behaviors, the degree of versatility and variability exhibited can justify attributing a sort of behavioral comprehension to them so long as we don't make the mistake of thinking of comprehension as some sort of stand-alone talent, a source of competence rather than a manifestation of competence.

== Part II: From Evolution to Intelligent Design ==
=== 6. What is Information? ===
* Did the information age begin:
** When people began writing things down, drawing maps, and otherwise recording and transmitting valuable information they couldn't keep in their heads with high fidelity?
** When people began speaking and passing on accumulated lore, history, and mythology?
** Over 530m ya, when eyesight evolved during the Cambrian Era, triggering an arms race of innovation in behavior and organs that could respond swiftly to the information gathered from the light?
** When life began - even the simplest reproducing cells survived thanks to parts that functioned by discriminating differences in themselves and and their immediate surroundings?
* Dennett focuses on "Semantic Information", which is so important to us that we want to be able to use if effectively, store it without loss, move it, transform it, share it, hide it.
* Memory can be conceived as an information channel, just as subject to noise as any telephone line.
* Analog to digital converors (ADCs), are analogous to the sensitive cells that accomplish transduction on the out input edges of the nervous system, though the conversion in brains is not into bit strings, but neuronal spike trains.
* McCulloch and Pitts, in 1943, demonstrated the logical possibility of a general purpose representing-and-learning-and-controlling network made out of units that performed simple, nonmiraculous, clueless tasks - a comprehender of sorts made of merely competent parts.
* The brain is certainly not a digital computer running binary code, but it is still a kind of computer.
* Economic information is whatever is worth some work.
* Survival depends on information, on differential and asymmetric information: I know some things you don't know.
* Semantic information is design worth getting - design always involves R1D work of some kind, using available semantic information to improve the prospects of something by adjusting its parts in some appropriate way.
* One can actually improve one's design as an agent in the world by just learning useful facts. All learning, learning what and learning how, can be a valuable supplement or revision to the design you were born with.
* Semantic information is a distinction that makes a difference, a difference that makes a difference.
* Information in general is that which justifies representational activity, that which determines form.
* Misinformation and disinformation are dependent or even parasitic kinds of information. Disinformation is the designed exploitation of another agent's systems of discrimination, which themselves are designed to pick up useful information and use it.
* Most of what anybody knows is adaptively inert, but cheap to store, and the bits that do matter, really matter.
* Advertisers and propagandists seek to build "outposts of recognition" in other agents minds.
* In natural selection, R&D happens, designs are improved because they all have to "pay for themselves" in differential reproduction, and Darwinian lineages "learn" new tricks by adjusting their form. They are, then, in-formed, a valuable step up in local design space.
* In the same way, Skinnerian, Popperian, and Gregorian creatures inform themselves during their own lifetimes by their encounters with their environments, becoming ever more effective agents thanks to the information they can now use to do all manner of new things, including developing new ways of further informing themselves. The rich get richer. And the richer and richer, using their information to refine the information they use to refine the information they use to refine the information they obtain by the systems they design to improve the information available to them when they set out to design something.
* Useful information is a descendent of JJ Gibson's affordances.
* Information is that which is selected.
* What semantic information can be gleaned from an event depends on what information the gleaner already has accumulated.
* Offspring inherit a manifest image with an ontology of affordances from their parents and are born ready to distinguish the things that are most important to them.
* Evolution is all about turning bugs into features, and turning noise into signal
* Where does all the information in DNA come from? From the gradual, purposeless, nonmiraculous transformation of noise into signal, over billions of years.
* Information is always relative to what the receiver already knows.
* Remembering is not simply retrieving some thing that has been stored in some place in the brain.
* Don't acquire and maintain what doesn't pay for itself. More is not always better. Intentional mind-clearing or unlearning is not an unusual phenomenon.
* So much of the semantic information that streams into our heads each day is not worth getting.
* Within an organism the information-transmitting channels tend to be highly reliable.
* The brain's job in perception is to filter out, discard, and ignore all but the noteworthy features of the flux of energy striking one's sensory organs.
* Semantic information:
** Is valuable - misinformation and disinformation are either pathologies or parasitic perversions of the default cases.
** Its value is receiver-relative and not measurable in any nonarbitrary way but can be confirmed by empirical testing
** The amount carried or contained in any delimited episode or item is also not usefully measurable in units but roughly comparable in local circumstances
** Need not be encoded to be transmitted or saved.
* Utility or function counts against a creation, since copyright is intended to protect "artistic" creation.
* You have to be informed to begin with, you have to have many competences installed, before you can avail yourself of information. How are humans so much better at extracting information from the environment than any other species?
* We have many more affordances - a hardware store is a museum of affordances.
* Information is information, not matter or energy. No materialism that does not admit this can survive at the present day.

=== 7. Darwinian Spaces: An Interlude ===
* Darwin talked of "the infinite complexity of the relations of all organic beings to each other and to their conditions of existence".
* Evolution by natural selection is change in a population due to:
** variation in the characteristics of members of the population,
** which causes different rates of reproduction, and
** which is heritable.
* Whenever all three factors are present, evolution by natural selection is the inevitable result, whether the population is organisms, viruses, computer programs, words, or some other variety of things that generate copies of themselves one way or another.
* Darwin discovered the fundamental algorithm of evolution by natural selection, an abstract structure that can be implemented in different materials or media.
* Darwin refutes essentialism, the ancient philosophical doctrine that claimed that for each type of thing, each natural kind, there is an essence, a set of necessary and sufficient properties for being that kind of thing. But in fact there is no principled way of drawing a line between related things.
* A Darwinian space is a 3D array to show 3 variables and see to what extent a process is pure Darwinism, quasi-Darwinian, proto-Darwinian, or not Darwinian at all.
* Evolutionary processes are themselves evolutionary products and as a result emerge gradually and transform gradually.
* Looking at this is "Darwinism about Darwinism".
* We could for example look at the relationship between:
** Fidelity of heredity. Evolution depends on high-fidelity copying but not perfect copying, since mutations (copying errors) are the ultimate source of all novelty.
** Dependence of realized fitness differences on intrinsic properties. The differences in fitness between members of a population may depend on "luck" or "talent" or any combination in between. When luck is dominant, you can have genetic drift, when some random feature gets boosted to fixation.
** Continuity (smoothness of fitness landscapes). Natural selection is a gradual process and depends on blindly taking "small steps". When the landscape is "rugged" (rapidly changing), evolution is next to impossible since small steps are uncorrelated with progress or even maintaining one's fitness.
* De-Darwinizing is when a lineage that evolved for generations under paradigmatic Darwinian conditions moves into a new environment where its future comes to be determined by a less Darwinian process.
* The developmental process that wires up your brain is a de-Darwinized version of the process that evolved the eukaryotes. There are many neurons in your brain at birth and only those that make the right connections are saved, but they just happen to be in the right place at the right time.
* The origin of life (from the abiotic world to bacteria) is a set of processes that went from pre-Darwinian to proto-Darwinian to Darwinian.
* You can look at cultural evolution using a Darwinian space with the axes:
** Growth vs reproduction - eg the Roman Catholic Church grwos but seldom spawns descendants these days, while the Hutterites are designed to send of daughter communities whenever a community gets big enough. Religions are large complex social entities. Words are more like viruses, simpler, unliving, and dependent on their hosts for reproduction.
** Cultural vs genetic - Trust is (mainly) a cultural phenomenon
** Internal complexity
* An inverted Darwinian space shows Darwinian at the base and intelligent design at the opposite extreme, with the following axes:
** Bottom-up vs top-down - Human culture started out profoundly Darwinian, with uncomprehending competences yielding various valuable structures in roughly the way termites build their castles, and then gradually de-Darwinized, becoming ever more comprehending, ever more efficient in its ways of searching design space. As human culture evolves, it fed on the fruits of its own evolution, increasing its design powers by utilizing information in ever more powerful ways.
** Comprehension
** Random vs directed search
* All the real cultural phenomena occupy the middle ground, involving imperfect comprehension, imperfect search, and much middling collaboration.
* We are the only species so far that has developed explosively cumulative culture. Culture has obviously been a good trick for us, but what barriers have stood in the way of other species developing it?

=== 8. Brains Made of Brains ===
* A bacterium can discriminate a few vital differences to make itself at home in its tiny Umwelt.
* Swift control is the key competence of mobile organisms, so nervous systems, with a headquarters, are obligatory. Brains are control centers for dealing swiftly and appropriately with the opportunities and risks - the affordances - of a mobile life.
* Brains are designed by natural selection to have, or reliably develop, equipment that can extract the semantic information needed for this control task.
* Other mammals, and birds, can afford to be [[altricial]] in contrast to [[precocial]]; they are designed to be fed and protected by parents through a prolonged infancy, picking up semantic information that doesn't have to come through their genes and doesn't have to be learned by unsheltered trial and error in the dangerous world.
* Brains develop competences, including the meta-competences needed to acquire and hone further consequences.
* Turing was the epitome of a top-down intelligent designer.
* Computer programming is top-halfway-down design; the grubby details of the "bottom" of the design is something you can ignore (unless the program you are writing is a compiler.
* Complex evolvable systems (basically all living, evolvable systems) depend on being organized "hierarchically": composed of parts that have some stability independently of the larger system of which they are parts, and that are themselves composed of similarly stable parts composed of parts. A structure - or a process - need be designed only once, and then used again and again, copied and copied not just between an organism and its offspring, but within an organism as it develops. As Dawkins has observed, a gene is like a toolbox subroutine in a computer.
* In the genome, there is a vertebra-making subroutine, a finger-making subroutine, and eyelid making subroutine, each of these are modular tasks.
* The developing organism sorta understand the commands of its genes the way a von Neumann machine sorta understands its machine language instructions - it sorta obeys them.
* Bottom-up R&D is Darwin's strange inversion, but brains are not exactly like digital computers:
** Brains are analog and computers are digital.
** Brains are parallel and computers are (mainly) serial. - The brain's architecture is massively parallel, with a vision system about a million channels wide, but many of the brain's most spectacular activities are (roughly) serial, in the so-called stream of consciousness, in which ideas, or concepts or thoughts float by not quite in single file, but through a von Neumann bottleneck of sorts.
** Brains are carbon based (protein etc) and computers are silicon.
** Brains are alive and computers are not?
* Deacon argues that, by divorcing information processing from thermodynamics, we restrict our theories to basically parasitical systems, artifacts that depend on a user for their energy, for their structural maintenance, for their interpretation, and for their raison d'être. It is important, he claims, that a brain be made of cells that are themselves autonomous little agents with agendas, chief of which is staying alive, which spawns further goals, such as finding work and finding allies. His insistence on making brains (or brain substitutes) out of living neurons might look at first like some sort of romanticism - protein chauvinism - but his reasons are practical and compelling.
* The hardware of existing digital computers depends critically on millions (or billions) of identical elements. Neurons, in contrast, are all different, and they get organized not through bureaucratic hierarchies, but by bottom-up coalition-formation, with lots of competition.
* What do neurons want? Do they have nano-intentionality, agency? They want the energy and raw materials they need to thrive. Neurons are, like yeast and fungi, highly competent agents in a life-or-death struggle, in the demanding environment between your ears, where the victories go to those cells that can network more effectively, contributing to more influential trends at the levels where large-scale human purposed and urges are discernible.
* A neuron is always hungry for work; it reaches out exploratory dendritic branches, seeking to network with its neighbors in ways that will be beneficial to it.
* Top-down intelligent designs depend on foresight, which evolution utterly lacks. Evolution's design are all in a way retrospective - this is what worked in the past.
* Variable selective environments, because of their unpredictability, favor the selection of incomplete designs, along with mechanisms to tune the design to suit the circumstances, exploitable plasticity or "learning".
* Brains are more like termite colonies than intelligently designed corporations or armies.
* An organism's Umwelt is populated by two R&D processes:
** evolution by natural selection and
** individual learning of one sort or another.
* An organism is floating in an ocean of differences, a scant few of which might make a difference to it. Born to a long lineage of successful copers, it comes pre-equipped with gear and biases for filtering out and refining the most valuable differences, separating the semantic information from the noise.
* Bayesian hierarchical predictive coding - a method of calculating probabilities based on ones prior expectation:
** Given that your expectations based on past experience (including the experience of your ancestors as passed down to you) are such and such (expressed as probabilites for each alternative), what effect on your future expectations should the following new data have? What adjustments in your probabilities would it be rational for you to make?
** It is a normative discipline, purportedly prescribing the right way to think about probabilities.
** Computer reading of handwriting involves a cascade of layers in which the higher layers make Bayesian predictions about what the next layer down in the system with "see" next. When the predictions proves false, they then generated error signals in response that lead to Bayesian revisions, which are then fed back down toward the input again and again, until the system settles on an identification.
** Practice makes perfect, and over time these systems get better and better at the job, the same way we do - only better.
* Hierarchical, Bayesian predictive coding is a method for generating affordances galore - we expect solid objects to have backs that will come into view as we walk around them, we expect doors to open stairs to afford climbing, and cups to hold liquid.
* The network doesn't sit passively, waiting to be informed, but constantly makes probabilistic guesses about what will come next and treating feedback about its errors as the chief source of new information to guide its next round of guesses.
* In visual pathways, for example, there are more downward than upward pathways, more outbound that incoming signals. The brain's strategy is continuously to create "forward models" or probabilistic anticipations, and use the incoming signals to prune them for accuracy.
* When the organism is in deeply familiar territory, the inbound corrections diminish to a trickle and the brain's guesses, unchallenged, give it a head start on what to do next.
* This is descended from "analysis by synthesis"
* In a Bayesian network, silence counts as confirmation. Whatever the higher levels guess counts as reality by default in the absence of disconfirmation.
* These are expectation-generating fabrics with a remarkable competence they don't need to understand. They don't need to express or represent the reasons they track; like evolution itself, they "blindly" separate the information wheat from the chaff and act on it. Reasons are not things in their ontologies, not salient items in their manifest images.
* And these systems come, via cultural evolution, a whole new process of R&D, less than 1m years old - that designs, disseminates, and installs thinking tools by the thousands in our brains (and only ours), turning them into minds - not "minds" or sorta minds, but proper minds.
* One kind of neuron, the von Economo, or spindle cell, is found only in animals with very large brains and complex social lives: humans and other great apes, elephants and cetaceans.
* Brains are computers:
** composed of billions of idiosyncratic neurons that evolved to fend for them selves,
** their functional architecture is more like a free market that a "politburo" hierarchy where all tasks are assigned from on high
** They are composed of Bayesian networdks that are highly competent expectation-generators that don't have to comprehend what they are doing.
** Our kind of comprehension is only made possible by the arrival quite recently of a new kind of evolutionary replicator - culturally transmitted information entities: [[memes]].

=== 9. The Role of Words in Cultural Evolution ===
* The evolution of the evolution of culture is from:
** Profoundly Darwinian processes - involving minimal comprehension, bottom-up generation of novel products by random search processes, to
** Processes of intelligent design - comprehending, top-down generation of novel products by directed search.
* Words are the best example of memes
* Other species have some rudiments of cultural evolution that are not transmitted genetically between the generation but rather are ways of behaving that depend on the offspring's perception of the elders' behavior - an "instinct to learn" things like nest building or singing.
* Many animal behaviors that were thought to be genetically transmitted "instincts" have proven to be "traditions" transmitted between parent and offspring.
* We are the only species so far to have richly cumulative culture and this is primarily due to language. We have had a sustained population growth unprecedented by any other vertebrate.
* Our genes haven't changed very much in the last 50k years, and the changes with have seen are driven by new selection pressures created by human cultural innovations, such as cooking, agriculture, transportation, religion, and science.
* The widespread adoption of a new way of behaving creates a one-way ratchet: once almost everybody is eating cooked food, the human digestion system evolves, genetically, to make it no longer practical - and then no longer possible - for humans to live on a raw diet.
* One of the facts of life, both genetic and cultural, is that options become obligatory. A clever new trick that gives is users a distinct advantage over their peers soon "spreads to fixation", at which point those who don't acquire it are doomed.
* Eccentricities of a few members of the population bezcome a species necessity, embodied in an instinct.
* There is no law obliging people to have a credit card or a cellphone, but it is increasingly inconvenient to not have them.
* Words are the lifeblood, the backbone, the DNA of cultural evolution.
* Languages evolve like species, and/but there is widespread anastomosis, whereby what had been distinct lineages join together, as words jump between languages.
* In bacteria and other unicellular organisms, genes are often traded or shared by a variety of processes independent of vertical gene descent (reproduction). Similarly, etymologies (descent lineages) for words are more secure than the descent of the languages in which they are found, because of horizontal word transfer between languages.
* Charles Sanders Peirce's type/token distinction:
** "Word" is a word, and there are three tokens of that word in this sentence.
** Tokens can also be silent events in your brain. These brain-tokens will not look like "word" or sound like "word (they're brain events and it's dark and quiet in there), but they will no doubt by physically similar to some of the events that normally occur in your brain when you see of hear "word".
** There are lots of intermediate cases of words - definite specific words - tokened in our minds without going into the distinction between spoken or written, heard or seen. And there also seems to be "wordless" thinking where we don't even go to the trouble of "finding" all the words, but just tokening their bare meanings.
** Internal tokens seem to resemble external tokens, but this is because they make use of the very same neural circuitry we use to detect the resemblances and differences between external tokens, not because this neural circuitry renders copies of what it identifies.
** Any process that makes a new token of a type from an existing token of a type counts as a replication, whether or not the tokens are physically identical or even very similar. Tokens of words are all physical things of one sort or another, but words are, one might say, made of information, like software, and are individuated by types, not tokens, in most instances.
* Words are structures in memory that are autonomous in the sense that they must be independently acquired (learned). They are items of information, and other informational structures include stories, poems, songs, slogans, catchphrases, myths, techniques, "best practices", schools of thought, creeds, superstitions, operating systems, web browsers, Java applets.
* Informational structures comes in various sizes from large novels to shorter poems and traffic signs.
* Words have, in addition to the visible or audible parts of their tokens, a host of informational parts (making them nouns and verbs, comparatives and plurals, etc).
* Words are autonomous in some regards; they can migrate from language to language and occur in many different roles, public and private.
* A word, like a virus, is a minimal kind of agent: it wants to get itself said. Every token it generates is one of its offspring. The set of tokens descended from an ancestor token form a type, which is thus like a species.
* Some of a word's offspring will be private utterances: its human host is talking to herself, maybe even obsessively rehearsing the word in her mind, over and over, a population explosion of tokens, building an ever more robust niche for itself in a brain. And it may well be that many more internal tokenings - offspring - are born outside our conscious attention altogether. At this very moment, words may be replicating competitively in your head as inconspicuously as microbes replicate in your gut.
* The problem with introspection is that it acquiesces in the illusion that there is an inner eye that sees and an inner ear that hears - and an inner mind that just thinks.
* How do words get themselves installed in infant brains? Children learn about seven words a day, on average, from birth to age six, by which time they have a vocabulary of about 15k words

=== 10. The Meme's-Eye Point of View ===
* What are memes made of? They are a kind of way of behaving (roughly) that can be copied, transmitted, remembered, taught, shunned, denounced, brandished, ridiculed, parodied, censored, hallowed.
* Memes are ways: ways of doing something, or making something, but not instincts (which are a different kind of ways of doing something or making something). The difference is that memes are transmitted perceptually, not genetically. They are semantic information, design worth stealing or copying, except when they are misinformation, which, like counterfeit money, is something that is transmitted or saved under the mistaken presumption that it is valuable, useful/
* Words are the best examples of memes.
* Repetition is a key ingredient in creating new affordances. Multiple copies of anything tend to enable your pattern-recognition machinery to make yet another copy, in the recognizer, and thus a meme can get spread.
* Words are high on reproduction versus growth, high on culture versus genetic, and low on complexity.
* Once words are secured as the dominant medium of cultural innovation and transmission, they do begin to transform the evolutionary process itself, giving rise to new varieties of R&D much closer to the traditional, mythical ideal of intelligent design
* Ideas, practices, methods, beliefs, traditions, rituals, terms. These are all informational things that spread among human beings.
* A meme is any culturally-based way.
* Three conceptions of memes:
** Competence without comprehension - Human comprehension - and approval - is neither necessary not sufficient for the fixation of a meme in a culture.
** The fitness of memes. Memes thus have their own reproductive fitness, just like viruses.
** Memes are informational things. They are “prescriptions” for ways of doing things that can be transmitted, stored, and mutated without being executed or expressed.
* Natural selection of memes can do the design work without any obligatory boost from human, divine, or group comprehension.
* Even the meanings of words can evolve by processes quite outside the ken of those using the words, thanks to differential replication. The fact that changes in cultural features can spread without notice is hare to account for. Memes provide an alternative vision of how culture-borne information gets installed in brains without being understood. The default presumption of folk psychology is that people, and even “higher” animals, will understand whatever is put before them.
* “ One could then say, with complete rigor, that it is the sea herself who fashions the boats, choosing those which function, and destroying the others.”
* No comprehension is required even if it probably accelerates R1D processes more often than it retards them.
* The meme perspective covers the whole spectrum of mutualist, commensal, and parasitical symbionts.
* Only a tiny minority of the trillions of viruses that inhabit each of us right now are toxic in any way. Do we need some viruses in order to thrive? We certainly need lots of our memes.
* Many memes, maybe most memes, are mutualists, fitness-enhancing prosthetic enhancements of our existing adaptations (such as our perceptual systems, our memories, our locomotive and manipulative abilities).
* The prospective of parasitical memes exploiting that infrastructure is more or less guaranteed.
* What does fitness means in the context of evolutionary biology? Not health or happiness or intelligence or comfort or security, but procreative prowess.
* We are the only species that has managed to occupy a perspective that displaces genetic fitness as the highest purpose, the summum bonum of life. We are the only species that has discovered other things to die for (and to kill for): freedom, democracy, truth, communism, Roman Catholicism, Islam, and many other meme complexes (memes made of memes
* We are the persuadable species, not just learners, not just trainable, but also capable of being moved by reasons represented to us, not free-floating. We often have reasons for what we do, in this sense: we have articulated them to ourselves and have endorsed them after due consideration. The individual human being’s capacity to reason, to express and evaluate logical arguments, arises out of the social practice of persuasion. Our skills were honed for taking sides, persuading others in debate, not necessarily getting things right.

=== 11. What's Wrong with Memes? Objections and Replies ===
* Palpable, foldable dollar bills that are physical objects are ontological crutches of sorts.
* Memes exist because words are memes, and words exist, and so do other ways of doing things that are transmitted nongenetically.
* Nobody invented tonal music, but many musicians and music theorists contributed to codifying it and choosing the syllables to sing for each tone and perfecting a system of musical notation; a fine mixture of Darwinian cultural evolution and intelligent design over hundreds of years beginning in the eleventh century. Tonal music is a good example of a digitized alphabet that allows correction to the norm (You’re singing that note a bit sharp. Fix it!) Many musical innovations involve bending, sliding, deliberately flatting the notes (for instance in the blues), but standing behind these deviations are the canonical tones.
* Melody-world, an important part of our manifest image.
* A purely semantic-level replication.
* Memes are informational structures that are normally valuable - they are worth copying - and copyright laws have been devised and refined to protect that value. Not only translations, faithful or not, but also abridgements, cinematic treatments, plays and operas based on novels, and even video games can count as meme replications.
* What is particularly important in this exploration of memes is that some of these higher levels really do depend on comprehension, not just copying competence, even though they are based on, and rely on, systems of copying competence that do not require comprehension. In fact, from this vantage point we can see that the high-fidelity copying of DNA, our chief model for replication, stands out as an extreme case of mindlessness in replication.
* At higher levels, with more sophisticated, more competent “readers”, you can create systems that can tolerate more physical variation. Spoken words are the chief example here, but there are others. Scrambled words are easily unscrambled. Sentences can be read even if the vowels are removed. Turing saw the importance of basing his great invention on as mindless a recognition system as he could imagine - binary choices between 0,1.
* A thinko is like a typo, but at a higher, semantic level - misthinking, not miswriting. A thinko is a clear mistake in any endeavor where the assumed goals of the enterprise require certain identifiable “best practices”.
* Routines are themselves memes, hones by differential replication over the generations and composable into larger practices that can be “read” and “written” by experts. Making arrows and axes, tending fires, cooking, sewing, weaving, making pots and doors and wheels and boats, and setting out fishnets are ways that can be corrected over many generations by the combined action of simple physical requirements and local traditions.
* A reliable way of enhancing fidelity of transmission via unreliable, low-fidelity individual memories.
* Unison chanting is ubiquitous in traditional religions and other ceremonies, and it similarly serves to repair the memories of the changers, none of whom could provide a faithful copy of last year’s rendition unaccompanied.
* It’s tempting to see a gradual transition from:
** “infectious” rhythmic entrainment among tribespeople repeating their favorite moves and imitating each other.
** More self-conscious rituals (with rehearsal required and deliberate teaching and correcting) - the domestication of dance with careful control of reproduction.
** Professional choreographers - memetic engineers, intelligently designing their art objects.
* The original ways of dancing were memes that nobody “owned”, mindlessly evolving to exploit human idiosyncrasies of skeleton, gait, perception, and emotional arousal, habits that spread because they could spread, like the common cold.
* Infectious bad habits can be hard to eradicate, but if they can morph into useful habits, their reproductive prospects are enhanced. Once recognize, at first dimly (Darwin’s unconscious selection) and then consciously (Darwin’s methodical selection), their reproduction would be more or less ensured by their hosts, so the memes could relax, become less exciting, less irresistible, less captivating, less vivid, and unforgettable because they had become so useful. (The brains of domesticated animals are always smaller than the brains of their nearest wild kin; use it or lose it, and domesticated animals have a relatively unchallenging life, being protected from predators and starvation, and provided with mates at procreation time.) The corollary of this, of couse, is that for something boring to spread, it has to be deemed by its hosts to be particularly useful, or particularly valuable, and hence worth breeding: inculcating via extensive training.
* In general, any artifact found in abundance and showing signs of use is a good thing; following this rule, you can often tell the good one from the not so good ones without knowing exactly why the good ones are good. Copy the good ones, of couse. Darwin’s brilliant idea of unconscious selection as the gradualist segue into domestication gets put to important use in cultural evolution as well. Our ancestors “automatically” ignored the runts of the litter, and the lemons of the fleet, and the result in each case was the gradual improvement (relative to human tastes and needs) of the offspring.
* As with genes, mutations are transmission errors, but on occasion such an error is a serendipitous improvement.
* A lot of evolutionary R&D went into improving the replication machinery of DNA during the first billion or so years of life. The invention of writing has similarly boosted the fidelity of linguistic transmission, and it was the product. of many minds in many places over several millennia. Few if any of the “inventors” of writing had - or needed to have - a clear vision of the “specs” of the machine they were inventing, the “problem” they were “solving” so elegantly.
* “The written medium allows more complexity because the words on a page don’t die on the air like speech, but can be rescanned until you figure out what the writer intended.”
* The memes of the near future may thrive without direct human intervention, still synanthropic, like barn swallow and chimney swifts, but dependent on the amenities of the technological niche constructed in the 20th C by humans.
* Genetic evolution (“instincts”) can’t operate fast enough to do the job, leaving a yawning gap to be filled by memetics, and no positive ideas of anything else coming from traditional approaches to culture that could do the job.
* Memetics can also help depsychologize the spread on innovations (good and bad). Cultural anthropology takes people to be, in the first place, perceivers, believers, rememberers, intenders, knowers, understanders, noticers - cultural innovations are noticed and then (often) adopted. Here is a vision of people as rational agents, intentional systems whose behavior can be predicted. Cultural goods deemed valuable are preserved, maintained, and either bequeathed to the next generation or sold to the highest bidder. But much cultural innovations happens by what might be called subliminal adjustments over long stretches of time, without needing to be noticed or consciously approved at all. These accumulated shifts can often be recognized in retrospect, as when an expatriate community is joined by a new person from the old country whose way of speaking is both strangely familiar and strangely unfamiliar: Aha! I remember we used to talk like that too!
* Not just pronunciation and word meaning can subliminally shift. In principle, attitudes, moral values, the most emblematic idiosyncrasies of a culture can soften, harden, erode, or become brittle at a pace too slow to perceive. Cultural evolution is lightning fast, compared to genetic evolution, but it can also be much too gradual for casual observation to discern.
* Then there are pathological cultural variants, maladaptive cultural innovations, which no current theory can account for.
* Darwinian evolutionary processes are amplifiers of noise. Evolutionary theory, not being able to predict the once-in-a billion events that in due course get amplified into new species, new genes, new adaptations, can’t predict the future except very conditionally.
* The meme’s eye view fills the large and awkward gap between genetically transmitted instincts and comprehended inventions, between competent animals and intelligent designers, and it fills it with the only kind of theoretical framework that can nomiraculously account for the accumulation of good design: differential replication of descendants.
* Genes can’t explain adaptations. That’s true, and why we need molecular biology, physiology, etc. Similarly, we need psychology, anthropology, economics, political science, history, philosophy, and literary theory to explian how and why cultural features (good and bad) work the way they do.
* Nobody is born a pries or a plumber or a prostitute, and how they got that way is not going to be explained by their genes alone or just by the memes that infest them. My overarching claim in this book is that the evolutionary perspective in general and the memetic perspective with regard to culture transform many of the apparently eternal puzzles of life, that is, meaning and consciousness, in ways inaccessible to those who never look beyond the manifest image that they grew up with and the disciplines they are trained in.
* There is no way for an acquired trait to adjust an organism’s genes so that the trait gets passed along to the next generation genetically. Cultural transmission permits any traits that are acquired by the parent to be inculcated in the young (by setting an example, by training, by admonition).
* In memetic evolution, it is the fitness of the memes themselves that is at stake, not the fitness of their hosts
* Memes don’t have genes.
* We can consider words, and memes more generally, to be the result of variable, temporally extended processes of reproduction, and imaginable variation on our normal mode of secual reproduction.
* Some of the marvels of culture can be attributed to the genius of their creators, but much less than is commonly imagined, and all rests on uncomprehending hosts of memes competing with each other for rehearsal time in brains.
* Perhaps the chief benefit of the meme’s-eye point of view is that it suggest questions about cultural phenomena that we might not otherwise think of asking, such as: Is x the result of intelligent design? Is x a good worth preserving and bequeathing or a bit or parasitic junk? Are there alternatives (alleles) to x that have been encountered and vanquished?
* Only when those accounts attribute comprehension to people (or mysterious social forces) for which there is no evidence, does our perspective provide a level playing field where all degrees and kinds of human comprehension can be located.
* “Descent with modification”

=== 12. The Origins of Language ===
* The origin of language is like the topic of the origin of life itself. Both are probably unique events on this planet. It is seen as "the hardest problem in science".
* What might the ancestors of today's well-designed languages have been? They were probably inefficient, hard-to-learn behavioral patterns that seldom "worked". What conditions had to be in place to make those early versions worth investing in? They may not even have "paid for" the expense of using them. They may have been parasitic habits that were infectious and hard to share. We should be on the lookout for a circuitous route, with gambits galore. The early days of language might have been more of an imposition than a gift.
* Functions that languages eventually serve:
** Communicative utility - command, request, inform, inquire, instruct, insult, inspire, intimidate, placate, seduce, amuse, entertain.
** Productivity - generate a vast number of different meanings (sentences, utterances) composed from a finite stoci of lexical items. There is no end to the number of grammatical sentences in English.
** Digitality - correct to the norms, rinsing much of the noise out of the signal
** Displaced Reference - refer to things not present in the environment of the communicators
** Ease of Acquisition - the remarkable swiftness with which spoken or signed language is picked up by children.
* No other species has a faculty remotely like human language in its power. We have an instinct to cooperate with our extended family, enhanced dispositions to cooperate. Words may be the best memes, but they weren't the first memes. Did group cooperation evolve before language? What benefit got our ancestors' children so interested in the vocalizations of their group and so eager to imitate them?
* Can we imagine young hominins acquiring the self-control and foresight to tend a fire effectively without verbal instruction? Could the cave paintings at Lascaux (20-30k ya) have been painted by H. sapiens artists without language.
* A bias that is apt to be more valuable than "copy anything that moves" or "copy the first adult you see" is "copy the majority" (conformist bias) "copy the successful" or "copy the prestigious".
* When does a habit of (basically clueless) copying do better than engaging in your own trial and error learning?
* Viruses can't reproduce on their own. They depend on commandeering the reliable copy machinery in the nucleus of living cells, and that copy machinery was the product of a billion years of R1D. Memes, helpful or not, must above all get themselves copied - dispositions to attend to others, and to copy some of the ways perceived, it the only ground in which memes could take root and bloom.
* Once a rudimentary copy system is in place, it can be hijacked by selfish interlopers. Perhaps we are just apes with brains being manipulated by memes in much the way we are manipulated by the cold virus. Instead of looking only at the prerequisite competences our ancestors needed, we should also consider unusual vulnerabilities that might make our ancestors the ideal hosts for infectious but nonvirulent habits (memes) that allowed us to live and stay mobile long enough for them to replicate through our populations. Perhaps we should think of astronauts going to the moon as the memes way of getting into the next generation of science nerds.
* Adaptations (fitness enhancers) can be either genetically or culturally transmitted. The genetic information highway has been optimized over billions of years with DNA copying machines, editing machines, and systems for dealing with genomic parasites. The cultural highway, over a much shorter time period, has also evolved a host of design features to facilitate reliable transmission of information. A coevolutionary process in which the "research" is mainly done by the memes and the later "development" is mainly done by the genes. Innovations in memes could provide the early "proof of concept' that would underwrite, in effect, the more expensive and time-consuming genetic adjustments in brain hardware that would improve the working conditions for both memes and their hosts.
* Software innovations leading the way and hardware redesigns following, innovations that were first designed as software systems, as simulations of new computers running on existing hardware computers. Today’s smartphones have, in addition to layers and layers of software running on software running on software, special-purpose graphics and speech-synthesis and recognition hardware in their microprocessors, the descendants of software systems that explored the Design Space first.
* Cellphones have special-purpose hardware for speech processing but not for speaking English of Chinese. In the same way, an infant brain is language neutral: versatility widens the “market” for the design.
* The Baldwin Effect reduces genetic variance and versatility by driving a behavior (or developmental option) into a “best practices” straitjacket controlled genetically, turning options into obligate behaviors.
* We can think of copiers as information scroungers and learners as information producers. Mindlessly copy the majority turns out to be a remarkably effective strategy. The individuals with competence (or behavioral comprehension) soon lose their advantage to the copiers.
* Cultural transmission won’t evolve except in a Goldilocks environment that is neither too hot - chaotic - nor too cold - unchanging - for long enough to provide evolution a chance to create some new habits and fix them in a population.
* Culture has been a spectacularly successful Good Trick for H sapiens.
* For bipedality, did rudimentary tool making create a selection pressure for the ability to carry raw materials or finished tools for long distances, or did upright walking, evolved for other reasons, open up the Design Space for effective tool making?
* Another proposed threshold is social intelligence. The competence to interpret others as intentional systems whose actions can be anticipated by observing what these others observe and figuring out what they want (food, escape, to predate you, a mating opportunity, to be left alone)
* Language may not be the foundation, but I wouldn’t call it the capstone; I would call it the launching pad of human cognition and thinking.
* Niche construction: organisms don’t just respond to the selective environment they are born into. Their activities can also revise the features of that environment quite swiftly, creating whole new selection pressures and relieving others. Our species has engaged heavily in niche construction. Steven Pinker calls our world the “cognitive niche”, stressing that it is a product of human comprehension. Others disagree, proposing that it would better be called the “cultural niche”, a platform of competences on which comprehension can grow. The R&D that has constructed the niche we inhabit today is a changing blend of both Darwinian, bottom-up processes and top-down intelligent design. Our niche is certainly unlike that of any other species. It includes hardly any prey or predators (unless you’re a fisherman or a surfer in shark-filled waters), where habitants are composed of almost nothing but artifacts and domesticated plants and animals, where social role, wealth, reputation, expertise, and style (of clothing, speaking, singing, dancing, playing) have largely supplanted stronger muscles, faster running, and keener eyesight as variable advantages that bestow genetic fitness.
* Some of these meme transmissions required joint attention, some required (proto-)linguistic direction, and some required fully linguistic instructions, including mnemonic mantras and other devices, no doubt.
* How can any parent animal convey some of its hard-won experience to its young without language. The capacity of language to direct attention to non- present things and circumstances is a huge enhancement.
* There is a gradient between “instinct” and “learned behavior”, not a dichotomy.
* Possible steps towards language:
** A proto-language of short utterances, lacking productivity or any distinction between imperatives and declaratives. These signals would be appropriate and recognized reactions to important affordances, and hence affordances themselves.
** Perhaps a gesture language rather like the signing languages of the Deaf came first, with vocalizations used for attention-grabbing and emphasis. Speaking without gesturing is a difficult feat for many people, and it might be that gesturing and vocalizing have traded places, with gestures now playing the embellishing role that was originally played by vocalizations. The vestigial hand movements so many of us find all but irresistible may in effect be fossil traces of the original languages.
** Perhaps there was an auditory “peacock’s tail” arms race, with male hominins vying to display their talent for musical vocalization, eventually including improvisations, like the competitive displays of nightingales and other songbirds.
* Language has two distinct compositional systems, “phonotactics” (governing which phonemes can follow which, independent of meaning) and “morphosyntax” (governing word order and the use of prefixes and suffices to build meanings out of meanings). Why two compositional levels, one semantic and one not? The productivity of languages is “motivated by” the usefulness of being able to communicate many things about the world.
* Depending on age and personality, people end up talking like the people around them, often without conscious effort. The evolution of vowel systems is thus a case of self-organization”. A system evolves not through any deliberate planning, but through the accumulation over time of a myriad of little adjustments by individuals responding to immediate pressures.
* It was in the interest of audible memes, meaningful or not, to distinguish themselves from the competition but also to exploit whatever habits of tongue prevailed locally, whereas it was in the interests of host/speaker/hearers to minimize the load on memory and articulation by keeping the repertoire of distinct sound-types fairly compact and efficient. No “conscious effort” is required because the immediate pressures are the selective pressures of differential replication.
* Over repetitions, the more readily perceived/remembered patterns survive while the others go extinct. And all are memes designed by differential replication to propagate in spite of providing not benefit beyond a reward for copying.
* A bounty of productively generated sounds looking for work is a more productive workshop of "invention" than a passel of distinctions with no sounds yet to express them. It takes a particular sort of intelligent designer to coin an apt and useful neologism. Sounds already in circulation could have been more or less unconsciously adopted to serve on particular occasions, the coinciding in experience of a familiar sound and a salient thing (two affordances) being wedded on the spot to form a new word, whose meaning was obvious in context.
* This populates the lexicon with phonology and semantics, but where does grammar come in? Isolated, conventionally fixed articulations are, like alarm calls, limited in semantic variety: hello, ouch, yikes, aaah, scram.
* The noun-verb distinction - Every language needs a topic/comment distinction (what you are talking about and what you are saying about it.
* Content words are almost never descended from function words.
* There is a robust negative correlation between the morphological complexity of a language and the size of the population that speaks it.
* Contact between adults speaking different languages tends to produce varieties of language in which morphological complexity is stripped out.
* The first words were, no doubt, assigned to the “things we had concepts for”, those things for which we were ready to discriminate these affordances, attend to them, track them, and then deal appropriately with them under normal circumstances.
* There are three kinds of entities: linguistic entities, mental entities, and worldly objects and relations. Two affordances unite to form something new, a concept in the specifically human sense of a word with an understood meaning.
* I can wonder what these things are called and what this sound means.
* Out of a rather chaotic jumble of opportunities, regularities can emerge, with only intermittent attention and hardly any intention. When things become familiar enough, they can be appropriated: my block, my dolly, my food, and my words - not at first consciously thought of as mine but just handled as possessions. With discrimination and recognition comes the prospect of reflection.
* The higher-order pattern of sameness and difference, which then become two additional things in the manifest image of the child. These iterated manipulations provide an engine of recombination from which the densely populated manifest image of a maturing human child can be constructed.
* Brains are well designed for picking up affordances of all kinds and refining the skills for responding to them appropriately. Once a brain starts being populated with pronounceable memes, they present as opportunities for mastery, and the pattern-finding powers of the brain get to work finding relations between them and the other available affordances.
* Children acquire the meaning of most of these words gradually via unconscious, involuntary statistical analysis of the multifarious stimuli they encounter.
* Can grammatical and morphological rules be acquired by bottom-up processes, competent and uncomprehending? Yes, since nobody learns the grammar of their first language “top-down”.
* At one extreme the wok is done by a pattern-finding competence that is completely general and has nothing specific in it about language, and at the other extreme is an almost-complete innate system (universal grammar) that just needs to have its “parameters” set for one language or another by experience.
* The mainly learning end of the spectrum suggests a ubiquitous gradualness, as much a feature of grammatical categories as of species and subspecies.
* Consider idioms like:
** One fell swoop and in cahoots that are quite impervious to internal analysis
** That doesn’t cut any ice and kick the bucket, whose meanings cannot be derived by analyzing their parts
** Pass muster and close quarters, which are analyzable if you have the context
** Prominent role, mixed message, and beyond repair, which are conventionalized but predictable
** Where the truth lies and bottom-up processes, which can be understood by anyone who knows the meaning of the components
* Grammaticalization takes frequently replicated combinations and gradually hardens them into units that can then replicate on their own as combinatorial units
* When, if ever, do any two speakers speak exactly the same language? We could say that each speaker has an idiolect, a dialect with a single native user
* If we reposition Chomsky’s Merge, or something like it, as an early candidate for a transitional innovation on the way to modern languages, then we can reconcile early and late Chomsky by saying the “intricate structure of specific rules and guiding principles” are not so much explicit rules as deeply embedded patterns in ways of speaking that consist of a series of improvements wrought by evolution, both cultural and genetic, in response to the success of protolanguages.
=== 13. The Evolution of Cultural Evolution ===
* Animals have some memes but they do not, in general, open up opportunities for further memes the way words do. There is none of the snowballing effect like language permits.
* Displaced reference is a giant step in Design Space.
* Human culture started out profoundly Darwinian, but the exploration of Design Space gradually de-Darwinized, as it developed cranes that could be used to build further cranes that lifted still more cranes into operation, becoming a process composed of ever more comprehension.
* Everything changed once language got in place, with growing comprehension, more top-down control, and more efficient directed search in a diagonal direction from pure Darwinian toward the (ultimately unreachable) summit of intelligent design, as we used more and more semantic information and hence design improvements.
* For there to be a population explosion of memes, there has to have been a preexisting (or concurrently evolving) instinct to imitate or copy, which would pay for itself by providing some genetic fitness benefit to our ancestors. Chimpanzees and bonobos, for instance, don’t exhibit the interest, the focused attention, the imitative talent required to kindle the cumulative cultural wildfire that marks us off from the other hominids.
* We became apes with meme-infected brains. The memes must have included enough mutualists and commensals among the parasites not to kill off their hosts, though it is entirely possible that waves of meme infection did just that before one wave finally happened to be benign enough to secure a long-term foothold. Bad habits, but catchy bad habits, would have been a price worth paying for a few really good habits.
* Once verbal communication became not just a Good Trick but an obligatory talent for our species, there would be steady selective pressure in favor of organic modifications that enhanced or streamlined the process of language acquisition, such as:
** altricity (prolonged infancy) - for education
** gaze monitoring
** shared attention
** shared intention
* The germs and viruses that occupy our bodies fly beneath our radar in most cases, and memes probably did the same. Our ancestors could have used words competently, and benefited from having words, without words being manifest to them as words in their manifest image. They would notice words, but they wouldn’t have to notice their noticing.
* Still the natural home of memes is in our manifest image, not our scientific image (where the vitamins and gut flora are found). They are, in general, available for noticing. Unlike viruses and microbes, memes are affordances we are equipped from the outset to notice, to recognize, to remember, to respond to appropriately. And when we notice our memes and start to own them and reflect on them, we have moved form the original image to the manifest image, the world we live in and know that we live in.
* Grice’s intentional model of communication - Real Gricean communication is a real pain (as anyone who’s ever been forced to engage in it will angrily tell you).
* Everyday communication is hugely unlike Gricean communication. Ordinary language may originate evolutionarily speaking in events somewhat like real Gricean communication events, but a great deal has changed since then and in particular a great deal has changed in our brains.
* Grice’s point was, or should have been, that human communicators have the competence to exploit these features - and the competence to avoid being exploited by others exploiting these features. The acquisition of a language and memes in general is like the installation of a software app like Photoshop, with many layers that most amateur users never encounter. With human communication, there is much variation, and most uses of the system are rudimentary, routine, guided by habits that are themselves beneath the ken of most observers (and self-observers). But the tools admit of some very sophisticated applications. Some people are natural manipulators, impression creators, masters of indirection and almost subliminal blandishment, and others are bluff, direct, naive, unguarded in their speech - novice users of the tools - but neither kind of people have to comprehend the reasons why their everyday communication tools have all the options that they do.
* Some people, especially high-functioning people on the autism spectrum manages to devise, with much effort and ingenuity, a genuine theory of mind (TOM), to help them interpret the kaleidoscopic social world that most of uscan “perceive directly”.
* If Grice’s theory was a performance theory, it would be applicable to a small minority of speakers.
* The free-floating rationale of the design of some of our practices is unimagined by us. Grice can be seen to have worked it our, seen the “order which is there” when people engage in nonnatural meaning, and simply presented it as an account of their intentional states at the time - overendowing people with reasons!
* Proto-labelings pave the way for labelings, and proto-requests pave the way for requests. It may take hundreds of hours of conversation before the child really gets the hang of it, and even longer before they understand what they are doing when they are having a conversation.
* It is one thing to hear yourself speaking and quite another to notice that you're saying something. Think of the double-take, too late: "Did I just say that? Did I really utter those words?"
* Early language users may only gradually have come to recognize retrospectively, what they have been doing. There was a gradual, incremental process of growing competence leading to self-monitoring, leading to reflection, leadining to the emergence of new things to think about: words and other memes in our manifest image.
* How can talking to yourself help? We may know things in one part of our brain that cannot be accessed by other parts of the brain when needed. The practice of talking to yourself creates new channels of communication that may, on occasion, tease the hidden knowledge into the open. The next time you try to solve a puzzle, consider indulging in a vocalized soliloquy: it's a good way to notice gaps in your thinking.
* Once you have a habit of going into question-posing mode, all your R&D becomes much more top-down, using more directed search, and relying less on random variation and retention. The search space can be squeezed by using information already acquired in other contexts to rule out large regions as unlikely or irrelevant - but only if the thinker can be reminded of it in a timely fashion. Talking to yourself, asking questions, or even just the inner rehearsal of relevant words ("key words"), is an efficient way of probing the networks of associations attached to each word, reminding you of overlooked possibilities that are likely to be relevant to your current perplexity.
* the ideal of a conscious human mind is one in which all its knowledge is equi-accessible, always available when needed, never distorted, a pandemonium of experts ready to lend a timely hand. An adult mind can - on rare occasions - exert significant discipline on the crew, prioritizing, squelching wasteful competition, and organizing the search parties.
* The ability to treat whatever topic is under consideration as itself a thing to be examined, analyzed, inventoried. These are meta-competences, in which we use our thinking tools to think about not just food, shelter, doors, containers, dangers, and the other affordances of daily life but also about thinking about food and shelter, and about thinking about thinking about food and shelter.
* I can't just install my meme in your brain and let it run. I have to secure your attention, your cooperation, evn - to some degree - your trust, because you are and ought to be vigilant against possible manipulation by other agents.
* Human culture is accelerating at an ever swifter pace, since more directed search and more top-down problem-setting leads to more efficient problem-solving. Among the enabling innovations were such brilliant "inventions" as writing arithmetic, money, clocks, and calendars, each contributing a novel and fecund system of representation that provided our manifest image with ever more portable, detachable, manipulable, recognizable, memorable things to do things with, to exploit in our growing mastery of other things. These were, so far as anyone can tell, Darwinian "inventions", that is inventions without inventors or foresighted authors, more like bird wings than helicopter blades.
* The free-floating rationales of the features and structures of these inventions have been gradually captured, represented, and celebrated by later beneficiaries, retrospective reverse engineers who could explain to the world the particular utility of phonemic representation of words, zero as a number, hard-to-counterfeit coins, representing time with a line or a circle or a volume, using a fixed short cycle of names for days. All of these culturally transmitted artifacts, abstract or concrete, are unmistakeably well-designed tools for thinking, but they were not the brainchildren of particular individual intelligent designers.
* The lore that builds up around these artifacts is the product of retrospective theorizing, not original invention, in most cases, byproducts of attempts to pass on the skills to apprentices, second-hand commentaries that may improve the understanding of the whole process - or may be "false consciousness", persuasive but mistaken theories of the topic. Sometimes problem "solvers" stumble on solutions without noticing or while misunderstanding what they have done. There is a general generous tendency to credit innovators with more prior comprehension than they actually deserve.
* The undeniable attractions of the rationality assumption. When we look at traditional accounts of cultural evolution, in the neutral sense of cultural change over time, the dominant theme is the economic model - as if all human cultural evolution took place near the ceiling of comprehension.
* We are indeed living in the age of intelligent design, and it goes back several millenia - as far back as we have documentation. From Aristotle's day to the present, the explanations and justifications of our storehouse of general knowledge are a kind of Whig history, written by the victors, triumphantly explaining the discoveries and passing over the costly mistakes and misguided searches. This huge backlog of nearly invisible cultural accumulation plays a role not unlike that of all the organisms in all the species who died childless but whose competition tested the mettle of those whose descendants live on today. Haydn and Mozart and Beethoven had to grow their talents in a world that included lots of slightly less talented or maybe just unlucky composers.
* But even in the most bureaucratic and rationalized of institutions, there are patterns of change - of evolution - that resist capture by the economic model, that appear as mere noise or happenstance, driven not by the rational pressures of the marketplace, but by arms races of Darwinian memetic evolution.
* Descending from the ceiling of pure rationality and looking at the middle ground, where semi-comprehending agents engage in semi-well-designed projects that generate a host of goibles, fresh new targets to attract foible-exploiters, equally semi-comprehending agents who sense, with varying degrees of accuracy, that their interests will be well served by adopting memes, adapting memes, revising memes designed (by a mixture, now, of natural selection and intelligent design) to take advantage of the weaknesses they seem to detect in their quarry. These arms races are the latest wave in the creative arms races that have driven genetic evolution for 3bn years, and they differ mainly in involving a significant degree of comprehension to lubricate and accelerate the innovations and reactions. This comprehension is overwhelmingly the product of language and other media of communication.
* Darwinian evolution by natural selection, lacking all foresight, rolls through populations that also lack foresight. The survivors are lucky. With us, there are well-developed traditions of gathering and passing along new advice as soon as it becomes available.
* Political advisors and advertisers, trend analyzers, and speculators aggressively observe and perturb the memosphere, prospecting for new moves, new opportunities, new cracks in the armor of skepticism and caution that all but the most naive people use to protect themselves. Everybody wants to go viral with their pet messages, while finding new ways of ignoring the surfeit of attention-grabbers that assault them. This fluidity of information transmission in human culture, and its use in combatting, discrediting, discarding, but also revising, improving, adapting and spreading new memes pushed Darwinian meme evolution into the background.
* Pinker restricts our attention to cultural treasures only, and exaggerates the role of intelligent design in creating these. But we have a demand for reasons that outstrips our ability to feed it. The normativity of reason-giving imposes itself even when we are at a loss for an answer. There is an obligation to have reasons that you can give for your behavior. This is the intentional stance in action, always presuming rationality. There must be a good reason or we wouldn't be doing it this way! From when children begin to speak, we begin to give them reasons: Don't touch - hot! Don't touch - dirty! Eat - it's good for you! Obedience, even blind obedience, is useful as a basis; there will be time for explaining and arguing later. Because I said so! is an important stage. And then, as we grow up, we are introduced to the norms of human society, which include, preeminently the presumption of rationality in each other, especially in adults.
* This is an ineliminable feature of language use; the presumption of comprehension is the default, so much so that when it is violated, we can become disoriented. We lead our daily lives bathed in the presumption of understanding. We expect people to expect us to have reasons, reasons we can express for whatever it is we are trying to do, and we effortlessly make up reasons - often without realizing it - when a query catches us without a pre-though answer. It is against this background that memetics looks so wrongheaded, so subversive, as Pinker says. We are the reasoners! We are the intelligent designers! We are the explainers of everything. It is an affront to suggest that some of our brainstorms are just that: cerebral disturbances caused by invading memes duking it out for dominance. We are in charge!
* And we are in charge, to a gratifying degree, capable of accepting and rejecting the ideas we encounter, discarding or developing them for reasons we can usually express.
* When a GOFAI tells you something, you can, in principle, always demand a reason, and it should be forthcoming. But the advent of LLMs with deep learning and Bayesian methods means that they won't be able to tell us.
* Long before we had designer brains, we had brains that were acquiring design-without-a-designer in the form of invading memes.
* A curious feature of our appreciation of wit or genius is that we prefer not to know how it is done. Timing is important for almost any intelligent act - which is why it is intelligent to anticipate and presolve problems wherever possible. All intelligent responses depend on costly R1D, and it doesn't make much difference how the work is distributed in time so long as the effects are timely.
* We want our minds to be "inspired" and "uncanny".
* Whether the "inspiration" is 1% or 99%, it must be a feature of a vehicle for exploring Design Space that has its own nonsupernatural R&D history, typically an unfathomable combination of genes, education, life experience, mentoring, and who knows what else - diet, the change overhearing of a strain of music, emotional imbalances temporary or permanent, and, yes, sometimes "insanity" - mental illness or pathology that has fortuitous benefits (for the art world if not for the artist).
* The multi-dimensional Design Space in which the Tree of Life has grown has now generated a daughter Design Space, for our brainchildren, and it has more dimensions and more possibilities than its parent, and we are (so far) the only species that can explore it.
* Steven Pinker is right that the human brain really is a designer, but this should be seen not as an alternative to the memetic approach, but as a continuation of the memetic approach into the age of gradually de-Darwinizing semi-intelligent design. Our traditional vision of genius portrays it as completely unlike natural selection in its creative powers, and it is no accident that genius is often see as divine, supernatural, Godlike. After all, we created God in our own (manifest) image, a natural overextension of the intentional stance into the cosmos.
* Our ancestors at the dawn of human culture didn't need understanding to acquire the new competences, and they didn't gain much understanding from having the new competences. As memes accumulated and became more and more effective at inhabiting their hosts. The manifest image became populated with more and more affordances, more and more opportunities to track, more and more things to do things with, more and more things - words - to use as tools to help keep track of things, and so forth. Some memes were tools, some toys, some were distractions, some were crippling parasites. They all depended on cultural replication to survive.
* We can see how a gradual, growing sophistication of behavior could arise by small innovations, adjustments, and refinements, building excellently designed cultural habits and institutions without much help from intelligent design. "First learning, then adaptations from learning.
* One of the most valuable innovations was the practice of putting marks in the environment to take a load off personal memory, one of the first forays of "the extended mind".
* Within a few millenia, we have Socrates and Plato and Aristotle talking about talking, thinking about thinking, imagining republics, theorizing about tragedy and comedy. The age of intelligent design is in full swing. Merely Skinnerian and Popperian creatures couldn't keep up with Gregorian creatures, their minds overflowing with new tools for making ever swifter and more accurate assessments of the complex environment confronting them. Brute force trial and error would no longer suffice; you had to comprehend to compete.
* We swim in an ocean of semi-intelligently designed, hemi-semi-demi-intelligently designed, and evolutionarily designed competitors, all still dependent on getting into new human brains to continue their lineages.

== Part III: Turning Our Minds Inside Out ==
=== 14. Consciousness as an Evolved User-Illusion ===
* The big questions:
** How do humans achieve "global" comprehension using "local" competences without invoking and intelligent designer?
** Do our minds differ from the minds of other animals, and if so how and why,
** How did our manifest image become manifest to us?
** Why do we experience things the way we do?
* Evolution has endowed all living things with the wherewithal to respond appropriately to their particular affordances:
** detecting and shunning the bad,
** detecting and obtaining the good,
** using the locally useful, and
** ignoring everything else
* This yields competence without comprehension, Nature uses the "Need to Know" principle, and designs highly successful, adept, even cunning creatures who have no idea what they are doing or why. Reasons abound, but they are mostly free-floating rationales, undreamt of by those who benefit from them.
* We know that it is like something to be us for the simple reason that we talk about it every day. Our introspective divulgences are behaviors that are just as observable and measurable as our acts of eating, running, fighting, and loving.
* In addition to all the free-floating rationales, there are the anchored reasons we represent to ourselves and others. These reasons are things for us - we can do things with them, we can think about them, and this permits them to influence our overt behaviors in ways unknown in other organisms.
* Our habits of self-justification are ways of behaving (ways of thinking) that we acquire in the course of filling our heads with culture-borne memes, including, importantly, the havits of self-reproach and self-criticism. Thus we learn to plan ahead, reason-venturing and reason-criticizing to presolve some of life's problems, using thinking tools to design our own future acts. No other animal does that.
* Our thinking is enabled by the installation of a virtual machine made of virtual machines made of virtual machines, and the apps installed on these VMs make our competences (somewhat) accessible to other people and to ourselves, as guests in our own brains.
* Communication is the only behavior that requires an organism to self-monitor its own control system.
* In the pandemonium model, goals are represented only tacitly, in the feedback loops that guide each task controller, but without any global or higher level representation. Evolution will tend to optimize the interrupt dynamics of these modules, and nobody's the wiser. That is, there doesn't need to be anyone home to be wiser!
* Communication requires a central clearing house of sorts in order to buffer the organism from revealing too much about its current state to competitive organisms. Many see communication as grounded in manipulation rather than as purely cooperative behavior. The buffer creates opportunities for "guided deception" and, coincidentally, opportunities for self-deception, by creating for the first time in history, explicit and more globally accessible representations of its current state.
* For a century and more philosophers have stressed the "privacy" of our inner thoughts, but seldom have they bothered to ask why this is such a good design feature; (An occupational blindness of many philosophers: taking the manifest image as simply given and never asking what it might have been given to us for).
* All organisms have a rudimentary sense of self - the free-floating rationales of the behavior of all organisms are organized around self-protection.
* As we learn to communicate, we need to perceive ourselves in the execution of these behaviors, and this is through a "selfy" sense of self. We need to keep track of what thoughts are ours and whether we should share them with others.
* It is like something to be you because you have been enabled to tell us - or refrain from telling us - what it's like to be you!
* When we evolved into an us, a communicating community of organisms that can compare notes, we became the beneficiaries of a system of user-illusion that rendered versions of our cognitive processes - otherwise as imperceptible as our metabolic processes - accessible to us for purposes of communication.
* If joint attention to a shared topic is required, there have to be things - affordances - that both the first and the second person can attend to, and this is what makes our manifest image manifest to us.
* The experience of will, then, is the way our minds portray their operations to us, not their actual operation.
* Curiously, our first-person point of view of our own minds is not so different from our second-person point of view of others' minds: we don't see or hear or feel the complicated neural machinery churning away in our brains but have to settle for an interpreted, digested version, a user-illusion that is so familiar to us that we take it not just for reality but also for the most indubitable and intimately known reality of all.
* Our access to our own thinking, and especially to the causation and dynamics of its subpersonal parts, is really no better than our access to our digestive processes. Consciousness is not just talking to yourself; it includes all the varieties of self-stimulation and reflection we have acquired and honed throughout our waking lives. These are not just things that happen in our brains, they are behaviors that we engage in, some instinctively (thanks to genetic evolution) and the rest acquired (thanks to cultural evolution and individual self-exploration).
* We cushion our ignorance with a false - but deeply tempting - model. We simply reproduce, with some kind of hand waving and apologies, our everyday model of how we know about what is going on outside us. The relative accessibility and familiarity of the outer part of the process of telling people what we see conceals us from the utter blank of the rest of the process. We have no more privileged access to that part of the process than we do to the complicated processes that maintain the connectivity between a telephone contact and us.
* Explanation has to stop somewhere, and here it is in the familiar mentalistic language of knowing and seeing, noticing and recognizing, and the like. The problem with the first-person point of view is that it is anchored in the manifest image, not the scientific image, and cannot avail itself of the resources of the scientific image. You can ask yourself what your subjective experience is, and see what you say. Then you can decide to endorse your own declaration, to believe it. You can do this by talking alound to yourself, talking silently to yourself, or "just thinking". We just look and learn, and that's all we know
* "Blurts" are proto-speech acts generated internally and tested to see whether they should be uttered overly.
* For Hume, the impression of causation we experience comes from inside, not outside. It is, itself, an effect of a habit of expectation that has been engrained in us over many waking hours. We are born with a sort of automatic causal sense, like a reflex, that is ready to "see" causation whenever our senses are confronted by the right kind of sequence of stimuli. This is part of the typically unexamined assumption that all perceptual representations must be flowing inbound from outside.
* Our ontology, in the elevantor sense, does a close-to-optimal job of cataloging the things in the world that matter to the behavior our brains have to control. Among the things in our Umwelt that matter to our well-being are ourselves! We ought to have good Bayesian expectations about what we will do next, what we will think next, and what we will expect next! And we do!
* Consciousness is a channel designed not for scientific investigation, but for handy, quick and dirty use in the rough and tumble of time-pressured life. Evolution has given us a gift that sacrifices literal truth for utility. The manifest image that has been cobbled together by genetic evolutionary processes over billions of years, and by cultural evolutionary processes over thousands of years, is an extremely sophisticated system of helpful metaphorical renderings of the underlying reality uncovered by the scientific image. The manifest image composes our Umwelt, the world we live in for almost all human purposes - aside from science.
* By presupposing that we normal folks are rational and hence have understanding (not just competence), we tacitly (and invalidly) endorse our everyday use of the intentional stance as the plain truth about human minds.
* By furnishing our minds with systems of representations, this architecture furnishes each of us with a perspective - a user-illusion - from which we have a limited, biased access to the workings of our brains, which we involuntarily misinterpret as a rendering (spread on the external world or on a private screen or stage) of both the world's external properties (colors, aromas, sounds, ;;;) and many of our own internal responses, (expectations satisfied, desires identified, etc). The incessant torrent of self-probing and reflection that we engage in during waking life is what permits us, alone, to comprehend our cometences and many of the reasons for the way the world is. Thanks to this infestation of culturally evolved symbiont information structures, our brains are empowered to be intelligent designers, of artifacts and of our own lives.

=== 15. The Age of Post-Intelligent Design ===
* Culture evolves through a mixture of dutiful obedience to tradition, heedless and opportunistic improvisation, and knowing, intentional, systematic R1D, irregularly punctuated with moments of "inspired" genius.
* Among the artifacts we have created is the concept of God, the Intelligent Designer, in our own image.
* We have created our environment, a perfectly real environment, but an artifact nonetheless, and we call it civilization.
* Language is the key invention, and it expands our individual cognitive powers by providing a medium for uniting them with all the cognitive powers of every clever human being who has ever thought.
* Asking better and better questions is the key to refining our search for solutions to our "mysteries", and language provides a practically limitless power to extend our grasp.
* John Cage: "When you start working, everybody is in your studio - the past, your friends, your enemies, the art world, and above all, your own ideas - all are there. But as you continue painting, they start leaving, one by one, and you are left completely alone. Then, if you're lucky, even you leave."
* Groups can do things, and (arguably) understand things, that individuals cannot, and much of our power derives from that discovery.
* Alfred North Whitehead: "Civilization advances by extending the number of important operations we can perform without thinking about them.
* We distinguish food from poison, and, like other locomoting organisms, we are extra sensitive to animacy (guided movements) in other moving things, and more particularly to the beliefs and desires (information and goals) that guide those movements, tracking as best we can who knows what and who wants what. This native bias is the genetic bias for the intentional stance, our practice of treating each other as rational agents guided by largely true beliefs and largely well-ordered desires. Our uninterrupted interest in these issues has generated the folk psychology that we rely on to make sense of one another. Our expectations are very frequently confirmed, which cements our allegiance to the intentional stance, and when our expectations are confounded, we tend to fall back on "explanations" of our failure that are at best inspired guesswork and at worst misleading mythmaking.
* The minds we prize most are the minds that are neither too predictable (boring, unchallenging) not too chaotic.
* We have begun designing and producing artifacts that can design and produce artifacts (that can design and produce artifacts...)
* Mainly, for the moment, we are producing artifacts that provide push-button automated processes that replace thousands of days of brilliant drudgery.
* The operators of these artifacts are using Darwin's methodical selection - the selective force of natural selection is focused through the nervous system of a discerning, purposeful, foresighted agent, using cascades of uncomprehending generate-and-test cycles that gradually refine the search process.
* Five tribes of machine learning:
** Symbolists - the descendants of GOFAI - the only ones that aren’t bottom-up, needle-in-haystack-finding repetetive churnings that gradually, with great reliability, home in on good (or good enough) answers to daunting problems.
** Connectionists - the descendants of logical neurons
** Evolutionaries - genetic algorithms and their offspring
** Bayesians - using practical algorithms for achieving the competences of hierarchical networks of Bayesian expectation-generators
** Analogizers - the descendants of nearest-neighbor algorithms.
* Things we make by hand (boats, bridges, engines, symphonies) we can (more or less) control as we construct, understanding each step along the way. Things we make “the old-fashioned way” (children, grandchildren) defy our comprehension because of our obliviousness to the details of the processes that create them. Today, we are generating brain-children, brain-grandchildren, etc, that depend on processes we cannot follow in detail, even when we can prove that the results are trustworthy.
* We can think of machine learning as the inverse of programming, in the same way that the square root is the inverse of the square, or integration is the inverse of differentiation
* Domingos: “All knowledge - past, present, and future - can be derived from data by a single, universal learning algorithm.
* We have seen how Bayesian networks are excellent at teasing out the statistical regularities that matter to the organism - its affordances. Animal brains, equipped by natural selection with such networks, can guide the bodies they inhabit with impressive adroitness, but by themselves have scant ability to adopt novel perspectives. That, I have argued, requires an infestation of memes, cognitive competences (habits, ways) designed elsewhere and installed in brains, habits that profoundly change the cognitive architecture of those brains, turning them into minds, in effect. So far, the onlhy animals whose brains are thus equipped are Home Sapiens.
* Just as the eukaryotic cell came into existence in a relatively sudden instance of technology transfer, in which two independent legacies of R&D were united in a single stroke of symbiosis to create a big leap forward, the human mind, the comprehending mind is - and had to be - a product of symbiosis, uniting the fruits of two largely independent legacies of R&D. We start, I have argued, with animal brains that have been, to a considerable extent

[[Category:Consciousness]]
[[Category:Books]]

From Bacteria to Bach and Back

2025-04-13T17:07:16Z

Rob: /* 12. The Origins of Language */

== Part I: Turning Our World Upside Down ==
=== 1. Introduction ===
* How come there are minds?
** Minds evolved and created thinking tools that eventually enabled minds to know how minds evolved, and even to know how these tools enabled them to know what minds are.
** What thinking tools? The simplest, on which all the others depend in various ways, are spoken words, followed by reading, writing, and arithmetic, followed by navigation and mapmaking, apprenticeship practices, and all the concrete devices for extracting and manipulating information that we have invented: compass, telescope, microscope, camera, computer, the Internet, and so on.
** These, in turn, fill our lives with technology and science, permitting us to know many things not known by other species. We know there are bacteria. Even bacteria don't know there are bacteria.
** Our minds are different. It takes thinking tools to understand what bacteria are, and we're the only species (so far) endowed with an elaborate kit of thinking tools.
* A birds-eye view of the journey:
** Life has been around on Earth for around 4bn years. The first 2bn were spent optimizing the machinery for self-maintenance, energy acquisition and reproduction, and the only living things were relatively simple, single-celled entities - bacteria or their cousins, archaea: the prokaryotes.
** Then an amazing thing happened. Two different prokaryotes collided and instead of one eating the other, it let it go on living, and, by dumb luck, found itself fitter, more competent in some way that mattered, than it had been before. This was perhaps the first successful instance of technology transfer. A fortuitous mutation almost never happens, but evolution depends on those rarest of rare events. This is the birth of the eukaryotes
** Every living thing big enough to be visible to the naked eye is a multicellular eukaryote.
** The Cambrian Explosion, which occurred over several million years about 530m ya, saw the sudden arrival of a bounty of new life forms.
** The "MacCready Explosion", at the dawn of human agriculture, about 10k ya, transformed the terrestrial vertebrate biomass (excluding insects, other invertebrates, and marine animals). At the beginning, humans plus their livestock and pets make up only 0.1%, and now we make up 98% (mostly cattle). This explosion is based on three factors - population, technology, and intelligence (our so-called native intelligence depends on both our technology and our population numbers).
* Dennett identified the "romantic" and "killjoy" sides of the duel over the stature of animal minds. We are not the God-like geniuses we think we are, but animals are not so smart either, and yet both humans and other animals are admirably equipped to deal "brilliantly" with many of the challenges thrown at them.

=== 2. Before Bacteria and Bach ===
* until there were systems that could be strictly called reproducing systems, the processes at work were only proto-evolutionary, semi-Darwinian, partial analogues of proper evolution by natural selection; they were processes that raised the likelihood that various combinations of ingredients would arise and persist, concentrating the feedstock molecules until this eventually led to the origin of life.
* A living thing must capture enough energy and materials, and fend off its own destruction long enough to construct a good enough replica of itself.
* The reverse-engineering perspective is ubiquitous in biology and is obligatory in investigations of the origin of life. It always involves some kind of optimality considerations: What is the simplest chemical structure that could possibly do x? Or would phenomenon x be stable enough to sustain process y?
* Orgel's second rule: "Evolution is cleverer than you are."
* Here is an example of a possible gambit in the origin of life:
** It is tempting to assume that the very first living thing capable of reproducing must have been the simples possible living thing (given the existing conditions on the planet at the time).
** Make the simples replicator you can imagine and then build on that foundation.
** But this is by no means necessary. It is possible, and more likely, I think, that a rather inelegantly complicated, expensive, slow, Rub-Goldberg conglomeration of objets trouvés was the first real replicator, and after it got the replication ball rolling, this ungainly replicator was repeatedly simplified in competition with its kin.
** Many of the most baffling magic tricks depend on the audience no imagining the ridiculously extravagant lengths magicians will go to in order to achieve a baffling effect. If you want to reverse-engineer magicians, you should always remind yourself that they have no shame, no abhorrence of bizarre expenditures for tiny effects that they can then exploit. Nature, similarly, has no shame - and no budget, and all the time in the world.
* [[Adaptionism]] is alive and well; reverse-engineering is still the royal road to discovery in biology.

=== 3. On the Origin of Reasons ===
* There are three strategies to adopt when trying to understand, explain, and predict phenomena:
** The physical stance - is the least risky but also the most difficult; you treat the phenomenon as obeying the laws of physics, and use physics to predict what will happen next.
** The design stance - is only for things that have been designed, either artifacts or living things or their parts, and have functions or purposes.
** The intentional stance - works primarily for things that are designed to use information to accomplish their functions. It works by treating the thing as a rational agent, attributing "beliefs" and "desires" and "rationality" to the thing, and predicting that it will act rationally.
* Evolution by natural selection is not itself a designed thing, an agent with purposes, but it acts as if it were. It is a set of processes that "find" and "track" reasons for things to be arranged one way rather than another.
* The reasons found by human designers are typically (but not always) represented in the minds of the designers, whereas the reasons uncovered by natural selection are represented for the first time by those human investigators who succeed in reverse-engineering Nature's productions.
* Our human world of reasons grew out of a world where there were no reasons.
* Two meanings of the word "why":
** What for - "Why are you handing me your camera?"
** How come - "Why does ice float?" This is asking for a cause or a process narrative
* Evolution by natural selection starts with "how come" and arrives at "what for". We start with a lifeless world in which there are no reasons, no purposes at all, but there are processes that happen.
* A central feature of human interaction, and one of the features unique to our species, is the activity of asking others to explain themselves, to justify their choices and actions, and then judging, endorsing, rebutting their answers, in recursive rounds of the "why?" game.
* Our capacity to respond appropriately in this reason-checking activity is the root of responsibility. Those who cannot explain themselves or cannot be moved by the reasons offered by others, those who are "dead to" the persuasions of advisors, are rightly judges to be of diminished responsibility and are treated differently by the law.
* The "logical space of reasons" is bound by norms, by mutual recognition of how things ought to go. Wherever there are reasons, there is room and need for some kind of justification and the possibility of correction when something goes wrong. This normativity is the foundation of ethics.
* But there are two kinds of norms and corrections:
** social normativity - concerned with social norms, practice, and collaboration
** instrumental normativity - concerned with quality control or efficiency, the norms of engineering
* Natural selection is an algorithmic process, a collection of sorting algorithms that are themselves composed of generate-and-test algorithms.
* In the prebiotic or abiotic world (before life), there were cycles at many spatio-temporal scales: seasons, night and day, tides, the water cycle, and thousands of chemical cycles discoverable at the atomic and molecular level, gradually changing the conditions in the world and thus raising the probability that something new will happen.
* This led to differential persistence, some temporary combinations of parts hang around longer than others. The rich can get richer, even though they can't yet bequeath their riches to descendants.
* Differential persistence must then somehow gradually turn into differential reproduction.
* "Serendipity" is when something good happens randomly, while "clobbering" is when something bad happens randomly.
* Walls or membranes that are randomly persisted are serendipitous in that they allow internal cycles to operate for a time without interference, and we see the engineering necessity of membranes to house the collection of chemical cycles - the Krebs cycle and thousands of others - that together permit life to emerge.
* Before we can have competent reproducers, we have to have competetent persisters. We are witnessing an automatic (algorithmic) paring away of the nonfunctional, crowded out by the functional.
* There are reasons why the parts are shaped and ordered as they are and this is the birth of reasons. Through Darwinism about Darwinism, we see the gradual emergence of the species of reasons out of the species of mere causes, what fors out of how comes*
* Natural selection is an automatic reason-finders, which "discovers" and "endorses" and "focuses" reasons over many generations.
* If there happens to be a "difference that happens to make a difference" then we have the germ of a reason, a proto-reason, and when this is selected to persist longer, then we can see emerge the accumulation of function by a process that blindly tracks reasons.
* Reasons existed before there were reasoners. There are reasons why trees spread their branches but they are not, in any strong sense, the trees' reasons. They don't "have" the reasons and they don't need to have the reasons.
* Darwin didn't extinguish teleology - he naturalized it.
* Reverse-engineering in biology is a descendant of reason-giving-judging.
* The evolution of what for from how come can be seen in the way we interpret the gradual emergence of living things via a cascade of prebiotic cycles. Free-floating rationales emerge as the reasons why some features exist; they do not presuppose intelligent designers, even though the designs that emerge are extraordinarily good.

=== 4. The Strange Inversions of Meaning ===
* The world before Darwin was held together not by science but by tradition, through the trickle-down theory of creation from God, which Darwin replaced by the bubble-up theory of creation.
* Design space:
** Skyhooks - float high in design space, unsupported by ancestors, the direct result of a special act of intelligent creation.
** Cranes - are non-miraculous innovations in design space that enable ever more powerful lifting and efficient exploration of the space. Endosymbiosis is a crane, as are sex and language and culture.
* Turing showed that it was possible to design mindless machines that were absolutely ignorant, but that could do arithmetic perfectly, following "instructions" that could be mechanically implemented.
* This is "competence without comprehension" and Turing saw that it could provide a traversable path in design space from absolute ignorance to artificial intelligence.
* All the brilliance and comprehension in the world arises ultimately out of uncomprehending competences compounded over time into ever more competent - and hence comprehending - systems.
* This overthrows the pre-Darwinian mind-first vision of Creation with a mind-last vision.
* Darwin discovered evolution by natural selection, while Turing invented the computer, but he is one of the twigs on the Tree of Life who is, himself, an indirect product of the blind Darwinian processes.
* Distribution of expertise or understanding of this sort is a hallmark of human creative processes.
* "Ontology" is the set of "things" that an animal can recognize and behave appropriately with regard to, and equally the set of things that a computer program has to be able to deal with to do its job. Humans have extremely varied ontologies. Some believe in electrons and some believe in abominable snowmen, but there is a huge common core that is shared by all normal human beings from around 6 years old:
** Manifest image - the things we use in our daily lives to anchor our interactions and conversations. For every noun in our everyday speech, there is a kind of thing it refers to. It comes along with your native language. It's the world according to us
** Scientific image - populated with molecules, atoms, electrons, gravity, quarks. But even scientists spend most of their day in the manifest image.
* These two versions of the world that are now quite distinct were once merged or intertwined in a single ancestral world of "what everybody knows" that included all the local fauna and flora and weapons and tools and dwellings and social roles, but also goblins and gods and miasmas and spells.
* We can treat animals as having different ontologies without settling issues of whether they are conscious of them or simply the beneficiaries of designs that can be interpreted (by reverse engineers or forward engineers) as having those ontologies.
* A well designed elevator:
** Has a kind of ontology. It is a good elevator if it interacts appropriately with its environment and its passengers. It uses variables to keep track of all the features of the world that matter to getting its job done and is oblivious to everything else.
** It has no need to know what its ontology is or why - the rationale of the program is something only the program's designers have to understand.
** Its prudent self-monitoring can be seen to be an elementary step towards consciousness.
* Even bacteria are good at staying alive, at making the right moves at the right times, but they have elevator-type minds, not elevated minds like ours. And these minds are the products of an R&D process of trial and error that gradually structured their internal machinery to move from state to state in a way highly likely - not guaranteed - to serve their limited but vital interests.
* But unlike the elevator there is noting at all that plays the rols of the labels or comments in a source program. There is nothing anywhere at any time in that R1D history that represents the rationales of it. But they can be discovered by reverse engineering - there is a reason why the parts are shaped as they are, why the behaviors are organized as they are, and that reason will "justify" the design (or an earlier design that has now become either vestigial or transformed by further evolution to serve some newer function.
* The elevator has replaced a human - the elevator operator - by a machine that "sorta" follows the same rules as the human. We humans often occupy this kind of intermediate level of consciousness where we have internalized or routinized through practice a set of explicit rules that we may then discard and even forget.
* The Manhattan project had a small number of intelligent designers who organized a massive group of people, most of whom knew nothing about what they were doing beyond their immediate tasks. The "need to know" principle means that it is possible to create very reliable levels of high competence with almost no comprehension for rather insulated tasks
* GOFAI can be seen in retrospect as an exercise in creating something rather Cartesian, a rationalistic expert with myriads of propositions stored in its memory, and all the understanding incorporated in its ability to draw conclusion. It relied on the comprehension of the designers to contrive systems composed of subsystems that were foresightedly equipped with exactly the competences they would need in order to handle the problems they might face.
* But modern deep-learning AI is bottom-up, using wasteful, mindless, less bureaucratic, more evolution-like processes of information extraction.
* Top-down intelligent designing works, but it is responsible for much less of the design in our world than is commonly appreciated.
* Comprehension, far from being a Godlike talent from which all design must flow, is an emergent effect of systems of uncomprehending competence; natural selection on one hand, and mindless computation on the other.

=== 5. The Evolution of Understanding ===
* Human designers start with a goal (which may be refined or abandoned along the way) and work top-down, with the designers using everything they know to guide their search for solutions to the design problems they set for themselves.
* Evolution, in contrast, has no goals, no predefined problems, and no comprehension to bring to the task.
* How could a slow, mindless process build a thing that could build a thing that a slow mindless process couldn't build on its own? A process with no Intelligent Designer can create intelligent designers who then design things that permit us to understand how a process with no Intelligent Designer can create intelligent designers who then design those things.
* An organism's "umwelt" is the behavioral environment that consists of all the things that matter to its well-being.
* "Affordances" are the relevant opportunities in the environment of any organism: things to eat of mate with, openings to walk through or look out of, holes to hide in, things to stand on, and so forth.
* Organsims can be the beneficiaries of design features that imply ontologies without themselves representing those ontologies.
* Biology is reverse-engineering, and reverse-engineering is methodically committed to optimality considerations. Bacteria don't know they are bacteria, but they respond to other bacteria in bacteria-appropriate ways and are capable of avoiding or tracking or trailing things they distinguish in their umwelt.
* In software engineering, there is a reason why debugging cannot be completely automated: what counts as a bug depends on all the purposes (and sub and sub-sub-purposes) of the software, and specifying in sufficient detail what those purposes are is, at least for practical purposes, the very same task as writing debugged code in the first place!
* Design revision in Nature must follow the profligate method of releasing and test-driving many variants and letting the losers die, unexamined.
* Evolution explores the "adjacent possible".
* Natural selection is full of bugs. Organisms are filled with all-but-undecipherable "spaghettit code" of undisciplined programmers, but the free-floating rationale of the whole system is clearly good enough for practical purposes.
* When does comprehension emerge?
* We are right to adopt the intentional stance to understand the benefits derived from competences, but these competences can be provided by the machinery without any mentality intruding at all.
* We can say that organisms with spectacular competences but without comprehension, are "gifted".
* When there isn't enough stability over time in the selective environment to permit natural selection to "predict" the future accurately (when "selecting" the best designs for the next generation), natural selection does better by leaving the next generation's design partially unfixed. Learning can take over where natural selection left off, optimizing the individuals in their own lifetimes by extracting information from the world encountered and using it to make local improvements.
* Costly-signalling theory, where an animal does something to deceive or distract a predator does not need comprehension. These animals cannot choose to deceive, they simply do it automatically in certain circumstances due to a "knee-jerk reflex".
* Comprehension is not the source of competence or the active ingrediant in competence - instead, it is composed of competences.
* The illusion that understanding is some additional, separable mental phenomenon is fostered by the aha! phenomenon, or eureka effect.
* Comprehension comes in degrees, but even at the highest levels of competence, comprehension is never absolute. All comprehension is sorta comprehension from some perspective.
* We count on experts to have deep "complete" understanding of difficult concepts we rely on every day, only half-comprehendingly, and language is the capacity to transmit, faithfully, information we only sorta understand.
* The Beatrix Potter syndrome, or intentional stance towards animals works whether the rationales it adduces are free floating or explicitly represented in the midst of the agents we are predicting.
* Whatever is going on in the animal's brain has the competence to detect and respond appropriately to the information in the environment. But the intentional stance just gives the specs for the mind and leaves the implementation for later.
* We idealize everybody's thinking, and even our own access to reasons, blithely attributing phantom bouts of clever reasoning to ourselves after the fact. Asked "Why did you do that?", the most honest thing to say is often "I don't know, it just came to me," but we often succumb to the temptation to engage in whig history, not settling for how come but going for what for.
* Four grades of competence:
** Darwininian Creatures - Have predefined and fixed competences created by the R&D of evolution. They are born hard-wired, knowing all they will ever know, they are gifted but not learners.
** Skinnerian Creatures - Have, in addition, the ability to adjust their behavior in reaction to "reinforcement". They start out with some "plasticity". They more or less randomly generate new behaviors to test the world and those that get reinforced are more likely to recur in similar circumstances in the future.
** Popperian Creatures - Look before they leap. They extract information about the cruel world and keep it handy, so they can use it to pretest hypothetical behaviors offline. Eventually they must act in the real world, but their first choice is not random, having won the generate-and-test competition trial runs in the internal environment model. The "habit" of "creating forward models" of the world and using them to make decision and modulate behavior is a fine habit to have, whether or not you understand it.
** Gregorian Creatures - Their Umwelt is well stocked with thinking tools, both abstract and concrete. Only with them do we find the deliberate introduction and use of thinking tools, systematic exploration of possible solutions to problems, and attempts at higher-order control of mental searches. Only we human beings are Gregorian creatures, apparently.
* The smartest animals are not "just" Skinnerian creatures but Popperian creatures, capable of figuring out some of the clever things they have been observed to do. They engage in exploratory behavior. They need not know that this is the rationale for their behavior, but they benefit from it by reducing uncertainty. The fact that they don't understand the grounds of their own understanding is no barrier to calling it understanding, since we humans are often in the same ignorant state about how we manage to figure out novel things.
* Some animals, like us, have something like an inner workshop, a portable design-improvement facility.
* An unconscious mind is no longer seen as a contradiction in terms. The puzzle today is what is consciousness for (if anything)?
* Animals, plants, and even microorganisms are equipped with competences that permit them to deal appropriately with the affordances of their environments. There are free-floating rationales for all these competences, but the organisms need not appreciate or comprehend them to benefit from them, nor do they need to be conscious of them. In animals with more complex behaviors, the degree of versatility and variability exhibited can justify attributing a sort of behavioral comprehension to them so long as we don't make the mistake of thinking of comprehension as some sort of stand-alone talent, a source of competence rather than a manifestation of competence.

== Part II: From Evolution to Intelligent Design ==
=== 6. What is Information? ===
* Did the information age begin:
** When people began writing things down, drawing maps, and otherwise recording and transmitting valuable information they couldn't keep in their heads with high fidelity?
** When people began speaking and passing on accumulated lore, history, and mythology?
** Over 530m ya, when eyesight evolved during the Cambrian Era, triggering an arms race of innovation in behavior and organs that could respond swiftly to the information gathered from the light?
** When life began - even the simplest reproducing cells survived thanks to parts that functioned by discriminating differences in themselves and and their immediate surroundings?
* Dennett focuses on "Semantic Information", which is so important to us that we want to be able to use if effectively, store it without loss, move it, transform it, share it, hide it.
* Memory can be conceived as an information channel, just as subject to noise as any telephone line.
* Analog to digital converors (ADCs), are analogous to the sensitive cells that accomplish transduction on the out input edges of the nervous system, though the conversion in brains is not into bit strings, but neuronal spike trains.
* McCulloch and Pitts, in 1943, demonstrated the logical possibility of a general purpose representing-and-learning-and-controlling network made out of units that performed simple, nonmiraculous, clueless tasks - a comprehender of sorts made of merely competent parts.
* The brain is certainly not a digital computer running binary code, but it is still a kind of computer.
* Economic information is whatever is worth some work.
* Survival depends on information, on differential and asymmetric information: I know some things you don't know.
* Semantic information is design worth getting - design always involves R1D work of some kind, using available semantic information to improve the prospects of something by adjusting its parts in some appropriate way.
* One can actually improve one's design as an agent in the world by just learning useful facts. All learning, learning what and learning how, can be a valuable supplement or revision to the design you were born with.
* Semantic information is a distinction that makes a difference, a difference that makes a difference.
* Information in general is that which justifies representational activity, that which determines form.
* Misinformation and disinformation are dependent or even parasitic kinds of information. Disinformation is the designed exploitation of another agent's systems of discrimination, which themselves are designed to pick up useful information and use it.
* Most of what anybody knows is adaptively inert, but cheap to store, and the bits that do matter, really matter.
* Advertisers and propagandists seek to build "outposts of recognition" in other agents minds.
* In natural selection, R&D happens, designs are improved because they all have to "pay for themselves" in differential reproduction, and Darwinian lineages "learn" new tricks by adjusting their form. They are, then, in-formed, a valuable step up in local design space.
* In the same way, Skinnerian, Popperian, and Gregorian creatures inform themselves during their own lifetimes by their encounters with their environments, becoming ever more effective agents thanks to the information they can now use to do all manner of new things, including developing new ways of further informing themselves. The rich get richer. And the richer and richer, using their information to refine the information they use to refine the information they use to refine the information they obtain by the systems they design to improve the information available to them when they set out to design something.
* Useful information is a descendent of JJ Gibson's affordances.
* Information is that which is selected.
* What semantic information can be gleaned from an event depends on what information the gleaner already has accumulated.
* Offspring inherit a manifest image with an ontology of affordances from their parents and are born ready to distinguish the things that are most important to them.
* Evolution is all about turning bugs into features, and turning noise into signal
* Where does all the information in DNA come from? From the gradual, purposeless, nonmiraculous transformation of noise into signal, over billions of years.
* Information is always relative to what the receiver already knows.
* Remembering is not simply retrieving some thing that has been stored in some place in the brain.
* Don't acquire and maintain what doesn't pay for itself. More is not always better. Intentional mind-clearing or unlearning is not an unusual phenomenon.
* So much of the semantic information that streams into our heads each day is not worth getting.
* Within an organism the information-transmitting channels tend to be highly reliable.
* The brain's job in perception is to filter out, discard, and ignore all but the noteworthy features of the flux of energy striking one's sensory organs.
* Semantic information:
** Is valuable - misinformation and disinformation are either pathologies or parasitic perversions of the default cases.
** Its value is receiver-relative and not measurable in any nonarbitrary way but can be confirmed by empirical testing
** The amount carried or contained in any delimited episode or item is also not usefully measurable in units but roughly comparable in local circumstances
** Need not be encoded to be transmitted or saved.
* Utility or function counts against a creation, since copyright is intended to protect "artistic" creation.
* You have to be informed to begin with, you have to have many competences installed, before you can avail yourself of information. How are humans so much better at extracting information from the environment than any other species?
* We have many more affordances - a hardware store is a museum of affordances.
* Information is information, not matter or energy. No materialism that does not admit this can survive at the present day.

=== 7. Darwinian Spaces: An Interlude ===
* Darwin talked of "the infinite complexity of the relations of all organic beings to each other and to their conditions of existence".
* Evolution by natural selection is change in a population due to:
** variation in the characteristics of members of the population,
** which causes different rates of reproduction, and
** which is heritable.
* Whenever all three factors are present, evolution by natural selection is the inevitable result, whether the population is organisms, viruses, computer programs, words, or some other variety of things that generate copies of themselves one way or another.
* Darwin discovered the fundamental algorithm of evolution by natural selection, an abstract structure that can be implemented in different materials or media.
* Darwin refutes essentialism, the ancient philosophical doctrine that claimed that for each type of thing, each natural kind, there is an essence, a set of necessary and sufficient properties for being that kind of thing. But in fact there is no principled way of drawing a line between related things.
* A Darwinian space is a 3D array to show 3 variables and see to what extent a process is pure Darwinism, quasi-Darwinian, proto-Darwinian, or not Darwinian at all.
* Evolutionary processes are themselves evolutionary products and as a result emerge gradually and transform gradually.
* Looking at this is "Darwinism about Darwinism".
* We could for example look at the relationship between:
** Fidelity of heredity. Evolution depends on high-fidelity copying but not perfect copying, since mutations (copying errors) are the ultimate source of all novelty.
** Dependence of realized fitness differences on intrinsic properties. The differences in fitness between members of a population may depend on "luck" or "talent" or any combination in between. When luck is dominant, you can have genetic drift, when some random feature gets boosted to fixation.
** Continuity (smoothness of fitness landscapes). Natural selection is a gradual process and depends on blindly taking "small steps". When the landscape is "rugged" (rapidly changing), evolution is next to impossible since small steps are uncorrelated with progress or even maintaining one's fitness.
* De-Darwinizing is when a lineage that evolved for generations under paradigmatic Darwinian conditions moves into a new environment where its future comes to be determined by a less Darwinian process.
* The developmental process that wires up your brain is a de-Darwinized version of the process that evolved the eukaryotes. There are many neurons in your brain at birth and only those that make the right connections are saved, but they just happen to be in the right place at the right time.
* The origin of life (from the abiotic world to bacteria) is a set of processes that went from pre-Darwinian to proto-Darwinian to Darwinian.
* You can look at cultural evolution using a Darwinian space with the axes:
** Growth vs reproduction - eg the Roman Catholic Church grwos but seldom spawns descendants these days, while the Hutterites are designed to send of daughter communities whenever a community gets big enough. Religions are large complex social entities. Words are more like viruses, simpler, unliving, and dependent on their hosts for reproduction.
** Cultural vs genetic - Trust is (mainly) a cultural phenomenon
** Internal complexity
* An inverted Darwinian space shows Darwinian at the base and intelligent design at the opposite extreme, with the following axes:
** Bottom-up vs top-down - Human culture started out profoundly Darwinian, with uncomprehending competences yielding various valuable structures in roughly the way termites build their castles, and then gradually de-Darwinized, becoming ever more comprehending, ever more efficient in its ways of searching design space. As human culture evolves, it fed on the fruits of its own evolution, increasing its design powers by utilizing information in ever more powerful ways.
** Comprehension
** Random vs directed search
* All the real cultural phenomena occupy the middle ground, involving imperfect comprehension, imperfect search, and much middling collaboration.
* We are the only species so far that has developed explosively cumulative culture. Culture has obviously been a good trick for us, but what barriers have stood in the way of other species developing it?

=== 8. Brains Made of Brains ===
* A bacterium can discriminate a few vital differences to make itself at home in its tiny Umwelt.
* Swift control is the key competence of mobile organisms, so nervous systems, with a headquarters, are obligatory. Brains are control centers for dealing swiftly and appropriately with the opportunities and risks - the affordances - of a mobile life.
* Brains are designed by natural selection to have, or reliably develop, equipment that can extract the semantic information needed for this control task.
* Other mammals, and birds, can afford to be [[altricial]] in contrast to [[precocial]]; they are designed to be fed and protected by parents through a prolonged infancy, picking up semantic information that doesn't have to come through their genes and doesn't have to be learned by unsheltered trial and error in the dangerous world.
* Brains develop competences, including the meta-competences needed to acquire and hone further consequences.
* Turing was the epitome of a top-down intelligent designer.
* Computer programming is top-halfway-down design; the grubby details of the "bottom" of the design is something you can ignore (unless the program you are writing is a compiler.
* Complex evolvable systems (basically all living, evolvable systems) depend on being organized "hierarchically": composed of parts that have some stability independently of the larger system of which they are parts, and that are themselves composed of similarly stable parts composed of parts. A structure - or a process - need be designed only once, and then used again and again, copied and copied not just between an organism and its offspring, but within an organism as it develops. As Dawkins has observed, a gene is like a toolbox subroutine in a computer.
* In the genome, there is a vertebra-making subroutine, a finger-making subroutine, and eyelid making subroutine, each of these are modular tasks.
* The developing organism sorta understand the commands of its genes the way a von Neumann machine sorta understands its machine language instructions - it sorta obeys them.
* Bottom-up R&D is Darwin's strange inversion, but brains are not exactly like digital computers:
** Brains are analog and computers are digital.
** Brains are parallel and computers are (mainly) serial. - The brain's architecture is massively parallel, with a vision system about a million channels wide, but many of the brain's most spectacular activities are (roughly) serial, in the so-called stream of consciousness, in which ideas, or concepts or thoughts float by not quite in single file, but through a von Neumann bottleneck of sorts.
** Brains are carbon based (protein etc) and computers are silicon.
** Brains are alive and computers are not?
* Deacon argues that, by divorcing information processing from thermodynamics, we restrict our theories to basically parasitical systems, artifacts that depend on a user for their energy, for their structural maintenance, for their interpretation, and for their raison d'être. It is important, he claims, that a brain be made of cells that are themselves autonomous little agents with agendas, chief of which is staying alive, which spawns further goals, such as finding work and finding allies. His insistence on making brains (or brain substitutes) out of living neurons might look at first like some sort of romanticism - protein chauvinism - but his reasons are practical and compelling.
* The hardware of existing digital computers depends critically on millions (or billions) of identical elements. Neurons, in contrast, are all different, and they get organized not through bureaucratic hierarchies, but by bottom-up coalition-formation, with lots of competition.
* What do neurons want? Do they have nano-intentionality, agency? They want the energy and raw materials they need to thrive. Neurons are, like yeast and fungi, highly competent agents in a life-or-death struggle, in the demanding environment between your ears, where the victories go to those cells that can network more effectively, contributing to more influential trends at the levels where large-scale human purposed and urges are discernible.
* A neuron is always hungry for work; it reaches out exploratory dendritic branches, seeking to network with its neighbors in ways that will be beneficial to it.
* Top-down intelligent designs depend on foresight, which evolution utterly lacks. Evolution's design are all in a way retrospective - this is what worked in the past.
* Variable selective environments, because of their unpredictability, favor the selection of incomplete designs, along with mechanisms to tune the design to suit the circumstances, exploitable plasticity or "learning".
* Brains are more like termite colonies than intelligently designed corporations or armies.
* An organism's Umwelt is populated by two R&D processes:
** evolution by natural selection and
** individual learning of one sort or another.
* An organism is floating in an ocean of differences, a scant few of which might make a difference to it. Born to a long lineage of successful copers, it comes pre-equipped with gear and biases for filtering out and refining the most valuable differences, separating the semantic information from the noise.
* Bayesian hierarchical predictive coding - a method of calculating probabilities based on ones prior expectation:
** Given that your expectations based on past experience (including the experience of your ancestors as passed down to you) are such and such (expressed as probabilites for each alternative), what effect on your future expectations should the following new data have? What adjustments in your probabilities would it be rational for you to make?
** It is a normative discipline, purportedly prescribing the right way to think about probabilities.
** Computer reading of handwriting involves a cascade of layers in which the higher layers make Bayesian predictions about what the next layer down in the system with "see" next. When the predictions proves false, they then generated error signals in response that lead to Bayesian revisions, which are then fed back down toward the input again and again, until the system settles on an identification.
** Practice makes perfect, and over time these systems get better and better at the job, the same way we do - only better.
* Hierarchical, Bayesian predictive coding is a method for generating affordances galore - we expect solid objects to have backs that will come into view as we walk around them, we expect doors to open stairs to afford climbing, and cups to hold liquid.
* The network doesn't sit passively, waiting to be informed, but constantly makes probabilistic guesses about what will come next and treating feedback about its errors as the chief source of new information to guide its next round of guesses.
* In visual pathways, for example, there are more downward than upward pathways, more outbound that incoming signals. The brain's strategy is continuously to create "forward models" or probabilistic anticipations, and use the incoming signals to prune them for accuracy.
* When the organism is in deeply familiar territory, the inbound corrections diminish to a trickle and the brain's guesses, unchallenged, give it a head start on what to do next.
* This is descended from "analysis by synthesis"
* In a Bayesian network, silence counts as confirmation. Whatever the higher levels guess counts as reality by default in the absence of disconfirmation.
* These are expectation-generating fabrics with a remarkable competence they don't need to understand. They don't need to express or represent the reasons they track; like evolution itself, they "blindly" separate the information wheat from the chaff and act on it. Reasons are not things in their ontologies, not salient items in their manifest images.
* And these systems come, via cultural evolution, a whole new process of R&D, less than 1m years old - that designs, disseminates, and installs thinking tools by the thousands in our brains (and only ours), turning them into minds - not "minds" or sorta minds, but proper minds.
* One kind of neuron, the von Economo, or spindle cell, is found only in animals with very large brains and complex social lives: humans and other great apes, elephants and cetaceans.
* Brains are computers:
** composed of billions of idiosyncratic neurons that evolved to fend for them selves,
** their functional architecture is more like a free market that a "politburo" hierarchy where all tasks are assigned from on high
** They are composed of Bayesian networdks that are highly competent expectation-generators that don't have to comprehend what they are doing.
** Our kind of comprehension is only made possible by the arrival quite recently of a new kind of evolutionary replicator - culturally transmitted information entities: [[memes]].

=== 9. The Role of Words in Cultural Evolution ===
* The evolution of the evolution of culture is from:
** Profoundly Darwinian processes - involving minimal comprehension, bottom-up generation of novel products by random search processes, to
** Processes of intelligent design - comprehending, top-down generation of novel products by directed search.
* Words are the best example of memes
* Other species have some rudiments of cultural evolution that are not transmitted genetically between the generation but rather are ways of behaving that depend on the offspring's perception of the elders' behavior - an "instinct to learn" things like nest building or singing.
* Many animal behaviors that were thought to be genetically transmitted "instincts" have proven to be "traditions" transmitted between parent and offspring.
* We are the only species so far to have richly cumulative culture and this is primarily due to language. We have had a sustained population growth unprecedented by any other vertebrate.
* Our genes haven't changed very much in the last 50k years, and the changes with have seen are driven by new selection pressures created by human cultural innovations, such as cooking, agriculture, transportation, religion, and science.
* The widespread adoption of a new way of behaving creates a one-way ratchet: once almost everybody is eating cooked food, the human digestion system evolves, genetically, to make it no longer practical - and then no longer possible - for humans to live on a raw diet.
* One of the facts of life, both genetic and cultural, is that options become obligatory. A clever new trick that gives is users a distinct advantage over their peers soon "spreads to fixation", at which point those who don't acquire it are doomed.
* Eccentricities of a few members of the population bezcome a species necessity, embodied in an instinct.
* There is no law obliging people to have a credit card or a cellphone, but it is increasingly inconvenient to not have them.
* Words are the lifeblood, the backbone, the DNA of cultural evolution.
* Languages evolve like species, and/but there is widespread anastomosis, whereby what had been distinct lineages join together, as words jump between languages.
* In bacteria and other unicellular organisms, genes are often traded or shared by a variety of processes independent of vertical gene descent (reproduction). Similarly, etymologies (descent lineages) for words are more secure than the descent of the languages in which they are found, because of horizontal word transfer between languages.
* Charles Sanders Peirce's type/token distinction:
** "Word" is a word, and there are three tokens of that word in this sentence.
** Tokens can also be silent events in your brain. These brain-tokens will not look like "word" or sound like "word (they're brain events and it's dark and quiet in there), but they will no doubt by physically similar to some of the events that normally occur in your brain when you see of hear "word".
** There are lots of intermediate cases of words - definite specific words - tokened in our minds without going into the distinction between spoken or written, heard or seen. And there also seems to be "wordless" thinking where we don't even go to the trouble of "finding" all the words, but just tokening their bare meanings.
** Internal tokens seem to resemble external tokens, but this is because they make use of the very same neural circuitry we use to detect the resemblances and differences between external tokens, not because this neural circuitry renders copies of what it identifies.
** Any process that makes a new token of a type from an existing token of a type counts as a replication, whether or not the tokens are physically identical or even very similar. Tokens of words are all physical things of one sort or another, but words are, one might say, made of information, like software, and are individuated by types, not tokens, in most instances.
* Words are structures in memory that are autonomous in the sense that they must be independently acquired (learned). They are items of information, and other informational structures include stories, poems, songs, slogans, catchphrases, myths, techniques, "best practices", schools of thought, creeds, superstitions, operating systems, web browsers, Java applets.
* Informational structures comes in various sizes from large novels to shorter poems and traffic signs.
* Words have, in addition to the visible or audible parts of their tokens, a host of informational parts (making them nouns and verbs, comparatives and plurals, etc).
* Words are autonomous in some regards; they can migrate from language to language and occur in many different roles, public and private.
* A word, like a virus, is a minimal kind of agent: it wants to get itself said. Every token it generates is one of its offspring. The set of tokens descended from an ancestor token form a type, which is thus like a species.
* Some of a word's offspring will be private utterances: its human host is talking to herself, maybe even obsessively rehearsing the word in her mind, over and over, a population explosion of tokens, building an ever more robust niche for itself in a brain. And it may well be that many more internal tokenings - offspring - are born outside our conscious attention altogether. At this very moment, words may be replicating competitively in your head as inconspicuously as microbes replicate in your gut.
* The problem with introspection is that it acquiesces in the illusion that there is an inner eye that sees and an inner ear that hears - and an inner mind that just thinks.
* How do words get themselves installed in infant brains? Children learn about seven words a day, on average, from birth to age six, by which time they have a vocabulary of about 15k words

=== 10. The Meme's-Eye Point of View ===
* What are memes made of? They are a kind of way of behaving (roughly) that can be copied, transmitted, remembered, taught, shunned, denounced, brandished, ridiculed, parodied, censored, hallowed.
* Memes are ways: ways of doing something, or making something, but not instincts (which are a different kind of ways of doing something or making something). The difference is that memes are transmitted perceptually, not genetically. They are semantic information, design worth stealing or copying, except when they are misinformation, which, like counterfeit money, is something that is transmitted or saved under the mistaken presumption that it is valuable, useful/
* Words are the best examples of memes.
* Repetition is a key ingredient in creating new affordances. Multiple copies of anything tend to enable your pattern-recognition machinery to make yet another copy, in the recognizer, and thus a meme can get spread.
* Words are high on reproduction versus growth, high on culture versus genetic, and low on complexity.
* Once words are secured as the dominant medium of cultural innovation and transmission, they do begin to transform the evolutionary process itself, giving rise to new varieties of R&D much closer to the traditional, mythical ideal of intelligent design
* Ideas, practices, methods, beliefs, traditions, rituals, terms. These are all informational things that spread among human beings.
* A meme is any culturally-based way.
* Three conceptions of memes:
** Competence without comprehension - Human comprehension - and approval - is neither necessary not sufficient for the fixation of a meme in a culture.
** The fitness of memes. Memes thus have their own reproductive fitness, just like viruses.
** Memes are informational things. They are “prescriptions” for ways of doing things that can be transmitted, stored, and mutated without being executed or expressed.
* Natural selection of memes can do the design work without any obligatory boost from human, divine, or group comprehension.
* Even the meanings of words can evolve by processes quite outside the ken of those using the words, thanks to differential replication. The fact that changes in cultural features can spread without notice is hare to account for. Memes provide an alternative vision of how culture-borne information gets installed in brains without being understood. The default presumption of folk psychology is that people, and even “higher” animals, will understand whatever is put before them.
* “ One could then say, with complete rigor, that it is the sea herself who fashions the boats, choosing those which function, and destroying the others.”
* No comprehension is required even if it probably accelerates R1D processes more often than it retards them.
* The meme perspective covers the whole spectrum of mutualist, commensal, and parasitical symbionts.
* Only a tiny minority of the trillions of viruses that inhabit each of us right now are toxic in any way. Do we need some viruses in order to thrive? We certainly need lots of our memes.
* Many memes, maybe most memes, are mutualists, fitness-enhancing prosthetic enhancements of our existing adaptations (such as our perceptual systems, our memories, our locomotive and manipulative abilities).
* The prospective of parasitical memes exploiting that infrastructure is more or less guaranteed.
* What does fitness means in the context of evolutionary biology? Not health or happiness or intelligence or comfort or security, but procreative prowess.
* We are the only species that has managed to occupy a perspective that displaces genetic fitness as the highest purpose, the summum bonum of life. We are the only species that has discovered other things to die for (and to kill for): freedom, democracy, truth, communism, Roman Catholicism, Islam, and many other meme complexes (memes made of memes
* We are the persuadable species, not just learners, not just trainable, but also capable of being moved by reasons represented to us, not free-floating. We often have reasons for what we do, in this sense: we have articulated them to ourselves and have endorsed them after due consideration. The individual human being’s capacity to reason, to express and evaluate logical arguments, arises out of the social practice of persuasion. Our skills were honed for taking sides, persuading others in debate, not necessarily getting things right.

=== 11. What's Wrong with Memes? Objections and Replies ===
* Palpable, foldable dollar bills that are physical objects are ontological crutches of sorts.
* Memes exist because words are memes, and words exist, and so do other ways of doing things that are transmitted nongenetically.
* Nobody invented tonal music, but many musicians and music theorists contributed to codifying it and choosing the syllables to sing for each tone and perfecting a system of musical notation; a fine mixture of Darwinian cultural evolution and intelligent design over hundreds of years beginning in the eleventh century. Tonal music is a good example of a digitized alphabet that allows correction to the norm (You’re singing that note a bit sharp. Fix it!) Many musical innovations involve bending, sliding, deliberately flatting the notes (for instance in the blues), but standing behind these deviations are the canonical tones.
* Melody-world, an important part of our manifest image.
* A purely semantic-level replication.
* Memes are informational structures that are normally valuable - they are worth copying - and copyright laws have been devised and refined to protect that value. Not only translations, faithful or not, but also abridgements, cinematic treatments, plays and operas based on novels, and even video games can count as meme replications.
* What is particularly important in this exploration of memes is that some of these higher levels really do depend on comprehension, not just copying competence, even though they are based on, and rely on, systems of copying competence that do not require comprehension. In fact, from this vantage point we can see that the high-fidelity copying of DNA, our chief model for replication, stands out as an extreme case of mindlessness in replication.
* At higher levels, with more sophisticated, more competent “readers”, you can create systems that can tolerate more physical variation. Spoken words are the chief example here, but there are others. Scrambled words are easily unscrambled. Sentences can be read even if the vowels are removed. Turing saw the importance of basing his great invention on as mindless a recognition system as he could imagine - binary choices between 0,1.
* A thinko is like a typo, but at a higher, semantic level - misthinking, not miswriting. A thinko is a clear mistake in any endeavor where the assumed goals of the enterprise require certain identifiable “best practices”.
* Routines are themselves memes, hones by differential replication over the generations and composable into larger practices that can be “read” and “written” by experts. Making arrows and axes, tending fires, cooking, sewing, weaving, making pots and doors and wheels and boats, and setting out fishnets are ways that can be corrected over many generations by the combined action of simple physical requirements and local traditions.
* A reliable way of enhancing fidelity of transmission via unreliable, low-fidelity individual memories.
* Unison chanting is ubiquitous in traditional religions and other ceremonies, and it similarly serves to repair the memories of the changers, none of whom could provide a faithful copy of last year’s rendition unaccompanied.
* It’s tempting to see a gradual transition from:
** “infectious” rhythmic entrainment among tribespeople repeating their favorite moves and imitating each other.
** More self-conscious rituals (with rehearsal required and deliberate teaching and correcting) - the domestication of dance with careful control of reproduction.
** Professional choreographers - memetic engineers, intelligently designing their art objects.
* The original ways of dancing were memes that nobody “owned”, mindlessly evolving to exploit human idiosyncrasies of skeleton, gait, perception, and emotional arousal, habits that spread because they could spread, like the common cold.
* Infectious bad habits can be hard to eradicate, but if they can morph into useful habits, their reproductive prospects are enhanced. Once recognize, at first dimly (Darwin’s unconscious selection) and then consciously (Darwin’s methodical selection), their reproduction would be more or less ensured by their hosts, so the memes could relax, become less exciting, less irresistible, less captivating, less vivid, and unforgettable because they had become so useful. (The brains of domesticated animals are always smaller than the brains of their nearest wild kin; use it or lose it, and domesticated animals have a relatively unchallenging life, being protected from predators and starvation, and provided with mates at procreation time.) The corollary of this, of couse, is that for something boring to spread, it has to be deemed by its hosts to be particularly useful, or particularly valuable, and hence worth breeding: inculcating via extensive training.
* In general, any artifact found in abundance and showing signs of use is a good thing; following this rule, you can often tell the good one from the not so good ones without knowing exactly why the good ones are good. Copy the good ones, of couse. Darwin’s brilliant idea of unconscious selection as the gradualist segue into domestication gets put to important use in cultural evolution as well. Our ancestors “automatically” ignored the runts of the litter, and the lemons of the fleet, and the result in each case was the gradual improvement (relative to human tastes and needs) of the offspring.
* As with genes, mutations are transmission errors, but on occasion such an error is a serendipitous improvement.
* A lot of evolutionary R&D went into improving the replication machinery of DNA during the first billion or so years of life. The invention of writing has similarly boosted the fidelity of linguistic transmission, and it was the product. of many minds in many places over several millennia. Few if any of the “inventors” of writing had - or needed to have - a clear vision of the “specs” of the machine they were inventing, the “problem” they were “solving” so elegantly.
* “The written medium allows more complexity because the words on a page don’t die on the air like speech, but can be rescanned until you figure out what the writer intended.”
* The memes of the near future may thrive without direct human intervention, still synanthropic, like barn swallow and chimney swifts, but dependent on the amenities of the technological niche constructed in the 20th C by humans.
* Genetic evolution (“instincts”) can’t operate fast enough to do the job, leaving a yawning gap to be filled by memetics, and no positive ideas of anything else coming from traditional approaches to culture that could do the job.
* Memetics can also help depsychologize the spread on innovations (good and bad). Cultural anthropology takes people to be, in the first place, perceivers, believers, rememberers, intenders, knowers, understanders, noticers - cultural innovations are noticed and then (often) adopted. Here is a vision of people as rational agents, intentional systems whose behavior can be predicted. Cultural goods deemed valuable are preserved, maintained, and either bequeathed to the next generation or sold to the highest bidder. But much cultural innovations happens by what might be called subliminal adjustments over long stretches of time, without needing to be noticed or consciously approved at all. These accumulated shifts can often be recognized in retrospect, as when an expatriate community is joined by a new person from the old country whose way of speaking is both strangely familiar and strangely unfamiliar: Aha! I remember we used to talk like that too!
* Not just pronunciation and word meaning can subliminally shift. In principle, attitudes, moral values, the most emblematic idiosyncrasies of a culture can soften, harden, erode, or become brittle at a pace too slow to perceive. Cultural evolution is lightning fast, compared to genetic evolution, but it can also be much too gradual for casual observation to discern.
* Then there are pathological cultural variants, maladaptive cultural innovations, which no current theory can account for.
* Darwinian evolutionary processes are amplifiers of noise. Evolutionary theory, not being able to predict the once-in-a billion events that in due course get amplified into new species, new genes, new adaptations, can’t predict the future except very conditionally.
* The meme’s eye view fills the large and awkward gap between genetically transmitted instincts and comprehended inventions, between competent animals and intelligent designers, and it fills it with the only kind of theoretical framework that can nomiraculously account for the accumulation of good design: differential replication of descendants.
* Genes can’t explain adaptations. That’s true, and why we need molecular biology, physiology, etc. Similarly, we need psychology, anthropology, economics, political science, history, philosophy, and literary theory to explian how and why cultural features (good and bad) work the way they do.
* Nobody is born a pries or a plumber or a prostitute, and how they got that way is not going to be explained by their genes alone or just by the memes that infest them. My overarching claim in this book is that the evolutionary perspective in general and the memetic perspective with regard to culture transform many of the apparently eternal puzzles of life, that is, meaning and consciousness, in ways inaccessible to those who never look beyond the manifest image that they grew up with and the disciplines they are trained in.
* There is no way for an acquired trait to adjust an organism’s genes so that the trait gets passed along to the next generation genetically. Cultural transmission permits any traits that are acquired by the parent to be inculcated in the young (by setting an example, by training, by admonition).
* In memetic evolution, it is the fitness of the memes themselves that is at stake, not the fitness of their hosts
* Memes don’t have genes.
* We can consider words, and memes more generally, to be the result of variable, temporally extended processes of reproduction, and imaginable variation on our normal mode of secual reproduction.
* Some of the marvels of culture can be attributed to the genius of their creators, but much less than is commonly imagined, and all rests on uncomprehending hosts of memes competing with each other for rehearsal time in brains.
* Perhaps the chief benefit of the meme’s-eye point of view is that it suggest questions about cultural phenomena that we might not otherwise think of asking, such as: Is x the result of intelligent design? Is x a good worth preserving and bequeathing or a bit or parasitic junk? Are there alternatives (alleles) to x that have been encountered and vanquished?
* Only when those accounts attribute comprehension to people (or mysterious social forces) for which there is no evidence, does our perspective provide a level playing field where all degrees and kinds of human comprehension can be located.
* “Descent with modification”

=== 12. The Origins of Language ===
* The origin of language is like the topic of the origin of life itself. Both are probably unique events on this planet. It is seen as "the hardest problem in science".
* What might the ancestors of today's well-designed languages have been? They were probably inefficient, hard-to-learn behavioral patterns that seldom "worked". What conditions had to be in place to make those early versions worth investing in? They may not even have "paid for" the expense of using them. They may have been parasitic habits that were infectious and hard to share. We should be on the lookout for a circuitous route, with gambits galore. The early days of language might have been more of an imposition than a gift.
* Functions that languages eventually serve:
** Communicative utility - command, request, inform, inquire, instruct, insult, inspire, intimidate, placate, seduce, amuse, entertain.
** Productivity - generate a vast number of different meanings (sentences, utterances) composed from a finite stoci of lexical items. There is no end to the number of grammatical sentences in English.
** Digitality - correct to the norms, rinsing much of the noise out of the signal
** Displaced Reference - refer to things not present in the environment of the communicators
** Ease of Acquisition - the remarkable swiftness with which spoken or signed language is picked up by children.
* No other species has a faculty remotely like human language in its power. We have an instinct to cooperate with our extended family, enhanced dispositions to cooperate. Words may be the best memes, but they weren't the first memes. Did group cooperation evolve before language? What benefit got our ancestors' children so interested in the vocalizations of their group and so eager to imitate them?
* Can we imagine young hominins acquiring the self-control and foresight to tend a fire effectively without verbal instruction? Could the cave paintings at Lascaux (20-30k ya) have been painted by H. sapiens artists without language.
* A bias that is apt to be more valuable than "copy anything that moves" or "copy the first adult you see" is "copy the majority" (conformist bias) "copy the successful" or "copy the prestigious".
* When does a habit of (basically clueless) copying do better than engaging in your own trial and error learning?
* Viruses can't reproduce on their own. They depend on commandeering the reliable copy machinery in the nucleus of living cells, and that copy machinery was the product of a billion years of R1D. Memes, helpful or not, must above all get themselves copied - dispositions to attend to others, and to copy some of the ways perceived, it the only ground in which memes could take root and bloom.
* Once a rudimentary copy system is in place, it can be hijacked by selfish interlopers. Perhaps we are just apes with brains being manipulated by memes in much the way we are manipulated by the cold virus. Instead of looking only at the prerequisite competences our ancestors needed, we should also consider unusual vulnerabilities that might make our ancestors the ideal hosts for infectious but nonvirulent habits (memes) that allowed us to live and stay mobile long enough for them to replicate through our populations. Perhaps we should think of astronauts going to the moon as the memes way of getting into the next generation of science nerds.
* Adaptations (fitness enhancers) can be either genetically or culturally transmitted. The genetic information highway has been optimized over billions of years with DNA copying machines, editing machines, and systems for dealing with genomic parasites. The cultural highway, over a much shorter time period, has also evolved a host of design features to facilitate reliable transmission of information. A coevolutionary process in which the "research" is mainly done by the memes and the later "development" is mainly done by the genes. Innovations in memes could provide the early "proof of concept' that would underwrite, in effect, the more expensive and time-consuming genetic adjustments in brain hardware that would improve the working conditions for both memes and their hosts.
* Software innovations leading the way and hardware redesigns following, innovations that were first designed as software systems, as simulations of new computers running on existing hardware computers. Today’s smartphones have, in addition to layers and layers of software running on software running on software, special-purpose graphics and speech-synthesis and recognition hardware in their microprocessors, the descendants of software systems that explored the Design Space first.
* Cellphones have special-purpose hardware for speech processing but not for speaking English of Chinese. In the same way, an infant brain is language neutral: versatility widens the “market” for the design.
* The Baldwin Effect reduces genetic variance and versatility by driving a behavior (or developmental option) into a “best practices” straitjacket controlled genetically, turning options into obligate behaviors.
* We can think of copiers as information scroungers and learners as information producers. Mindlessly copy the majority turns out to be a remarkably effective strategy. The individuals with competence (or behavioral comprehension) soon lose their advantage to the copiers.
* Cultural transmission won’t evolve except in a Goldilocks environment that is neither too hot - chaotic - nor too cold - unchanging - for long enough to provide evolution a chance to create some new habits and fix them in a population.
* Culture has been a spectacularly successful Good Trick for H sapiens.
* For bipedality, did rudimentary tool making create a selection pressure for the ability to carry raw materials or finished tools for long distances, or did upright walking, evolved for other reasons, open up the Design Space for effective tool making?
* Another proposed threshold is social intelligence. The competence to interpret others as intentional systems whose actions can be anticipated by observing what these others observe and figuring out what they want (food, escape, to predate you, a mating opportunity, to be left alone)
* Language may not be the foundation, but I wouldn’t call it the capstone; I would call it the launching pad of human cognition and thinking.
* Niche construction: organisms don’t just respond to the selective environment they are born into. Their activities can also revise the features of that environment quite swiftly, creating whole new selection pressures and relieving others. Our species has engaged heavily in niche construction. Steven Pinker calls our world the “cognitive niche”, stressing that it is a product of human comprehension. Others disagree, proposing that it would better be called the “cultural niche”, a platform of competences on which comprehension can grow. The R&D that has constructed the niche we inhabit today is a changing blend of both Darwinian, bottom-up processes and top-down intelligent design. Our niche is certainly unlike that of any other species. It includes hardly any prey or predators (unless you’re a fisherman or a surfer in shark-filled waters), where habitants are composed of almost nothing but artifacts and domesticated plants and animals, where social role, wealth, reputation, expertise, and style (of clothing, speaking, singing, dancing, playing) have largely supplanted stronger muscles, faster running, and keener eyesight as variable advantages that bestow genetic fitness.
* Some of these meme transmissions required joint attention, some required (proto-)linguistic direction, and some required fully linguistic instructions, including mnemonic mantras and other devices, no doubt.
* How can any parent animal convey some of its hard-won experience to its young without language. The capacity of language to direct attention to non- present things and circumstances is a huge enhancement.
* There is a gradient between “instinct” and “learned behavior”, not a dichotomy.
* Possible steps towards language:
** A proto-language of short utterances, lacking productivity or any distinction between imperatives and declaratives. These signals would be appropriate and recognized reactions to important affordances, and hence affordances themselves.
** Perhaps a gesture language rather like the signing languages of the Deaf came first, with vocalizations used for attention-grabbing and emphasis. Speaking without gesturing is a difficult feat for many people, and it might be that gesturing and vocalizing have traded places, with gestures now playing the embellishing role that was originally played by vocalizations. The vestigial hand movements so many of us find all but irresistible may in effect be fossil traces of the original languages.
** Perhaps there was an auditory “peacock’s tail” arms race, with male hominins vying to display their talent for musical vocalization, eventually including improvisations, like the competitive displays of nightingales and other songbirds.
* Language has two distinct compositional systems, “phonotactics” (governing which phonemes can follow which, independent of meaning) and “morphosyntax” (governing word order and the use of prefixes and suffices to build meanings out of meanings). Why two compositional levels, one semantic and one not? The productivity of languages is “motivated by” the usefulness of being able to communicate many things about the world.
* Depending on age and personality, people end up talking like the people around them, often without conscious effort. The evolution of vowel systems is thus a case of self-organization”. A system evolves not through any deliberate planning, but through the accumulation over time of a myriad of little adjustments by individuals responding to immediate pressures.
* It was in the interest of audible memes, meaningful or not, to distinguish themselves from the competition but also to exploit whatever habits of tongue prevailed locally, whereas it was in the interests of host/speaker/hearers to minimize the load on memory and articulation by keeping the repertoire of distinct sound-types fairly compact and efficient. No “conscious effort” is required because the immediate pressures are the selective pressures of differential replication.
* Over repetitions, the more readily perceived/remembered patterns survive while the others go extinct. And all are memes designed by differential replication to propagate in spite of providing not benefit beyond a reward for copying.
* A bounty of productively generated sounds looking for work is a more productive workshop of "invention" than a passel of distinctions with no sounds yet to express them. It takes a particular sort of intelligent designer to coin an apt and useful neologism. Sounds already in circulation could have been more or less unconsciously adopted to serve on particular occasions, the coinciding in experience of a familiar sound and a salient thing (two affordances) being wedded on the spot to form a new word, whose meaning was obvious in context.
* This populates the lexicon with phonology and semantics, but where does grammar come in? Isolated, conventionally fixed articulations are, like alarm calls, limited in semantic variety: hello, ouch, yikes, aaah, scram.
* The noun-verb distinction - Every language needs a topic/comment distinction (what you are talking about and what you are saying about it.
* Content words are almost never descended from function words.
* There is a robust negative correlation between the morphological complexity of a language and the size of the population that speaks it.
* Contact between adults speaking different languages tends to produce varieties of language in which morphological complexity is stripped out.
* The first words were, no doubt, assigned to the “things we had concepts for”, those things for which we were ready to discriminate these affordances, attend to them, track them, and then deal appropriately with them under normal circumstances.
* There are three kinds of entities: linguistic entities, mental entities, and worldly objects and relations. Two affordances unite to form something new, a concept in the specifically human sense of a word with an understood meaning.
* I can wonder what these things are called and what this sound means.
* Out of a rather chaotic jumble of opportunities, regularities can emerge, with only intermittent attention and hardly any intention. When things become familiar enough, they can be appropriated: my block, my dolly, my food, and my words - not at first consciously thought of as mine but just handled as possessions. With discrimination and recognition comes the prospect of reflection.
* The higher-order pattern of sameness and difference, which then become two additional things in the manifest image of the child. These iterated manipulations provide an engine of recombination from which the densely populated manifest image of a maturing human child can be constructed.
* Brains are well designed for picking up affordances of all kinds and refining the skills for responding to them appropriately. Once a brain starts being populated with pronounceable memes, they present as opportunities for mastery, and the pattern-finding powers of the brain get to work finding relations between them and the other available affordances.
* Children acquire the meaning of most of these words gradually via unconscious, involuntary statistical analysis of the multifarious stimuli they encounter.
* Can grammatical and morphological rules be acquired by bottom-up processes, competent and uncomprehending? Yes, since nobody learns the grammar of their first language “top-down”.
* At one extreme the wok is done by a pattern-finding competence that is completely general and has nothing specific in it about language, and at the other extreme is an almost-complete innate system (universal grammar) that just needs to have its “parameters” set for one language or another by experience.
* The mainly learning end of the spectrum suggests a ubiquitous gradualness, as much a feature of grammatical categories as of species and subspecies.
* Consider idioms like:
** One fell swoop and in cahoots that are quite impervious to internal analysis
** That doesn’t cut any ice and kick the bucket, whose meanings cannot be derived by analyzing their parts
** Pass muster and close quarters, which are analyzable if you have the context
** Prominent role, mixed message, and beyond repair, which are conventionalized but predictable
** Where the truth lies and bottom-up processes, which can be understood by anyone who knows the meaning of the components
* Grammaticalization takes frequently replicated combinations and gradually hardens them into units that can then replicate on their own as combinatorial units
* When, if ever, do any two speakers speak exactly the same language? We could say that each speaker has an idiolect, a dialect with a single native user
* If we reposition Chomsky’s Merge, or something like it, as an early candidate for a transitional innovation on the way to modern languages, then we can reconcile early and late Chomsky by saying the “intricate structure of specific rules and guiding principles” are not so much explicit rules as deeply embedded patterns in ways of speaking that consist of a series of improvements wrought by evolution, both cultural and genetic, in response to the success of protolanguages.
=== The Evolution of Cultural Evolution ===
* Animals have some memes but they do not, in general, open up opportunities for further memes the way words do. There is none of the snowballing effect like language permits.
* Displaced reference is a giant step in Design Space.
* Human culture started out profoundly Darwinian, but the exploration of Design Space gradually de-Darwinized, as it developed cranes that could be used to build further cranes that lifted still more cranes into operation, becoming a process composed of ever more comprehension.
* Everything changed once language got in place, with growing comprehension, more top-down control, and more efficient directed search in a diagonal direction from pure Darwinian toward the (ultimately unreachable) summit of intelligent design, as we used more and more semantic information and hence design improvements.
* For there to be a population explosion of memes, there has to have been a preexisting (or concurrently evolving) instinct to imitate or copy, which would pay for itself by providing some genetic fitness benefit to our ancestors. Chimpanzees and bonobos, for instance, don’t exhibit the interest, the focused attention, the imitative talent required to kindle the cumulative cultural wildfire that marks us off from the other hominids.
* We became apes with meme-infected brains. The memes must have included enough mutualists and commensals among the parasites not to kill off their hosts, though it is entirely possible that waves of meme infection did just that before one wave finally happened to be benign enough to secure a long-term foothold. Bad habits, but catchy bad habits, would have been a price worth paying for a few really good habits.
* Once verbal communication became not just a Good Trick but an obligatory talent for our species, there would be steady selective pressure in favor of organic modifications that enhanced or streamlined the process of language acquisition, such as:
** altricity (prolonged infancy) - for education
** gaze monitoring
** shared attention
** shared intention
* The germs and viruses that occupy our bodies fly beneath our radar in most cases, and memes probably did the same. Our ancestors could have used words competently, and benefited from having words, without words being manifest to them as words in their manifest image. They would notice words, but they wouldn’t have to notice their noticing.
* Still the natural home of memes is in our manifest image, not our scientific image (where the vitamins and gut flora are found). They are, in general, available for noticing. Unlike viruses and microbes, memes are affordances we are equipped from the outset to notice, to recognize, to remember, to respond to appropriately. And when we notice our memes and start to own them and reflect on them, we have moved form the original image to the manifest image, the world we live in and know that we live in.
* Grice’s intentional model of communication - Real Gricean communication is a real pain (as anyone who’s ever been forced to engage in it will angrily tell you).
* Everyday communication is hugely unlike Gricean communication. Ordinary language may originate evolutionarily speaking in events somewhat like real Gricean communication events, but a great deal has changed since then and in particular a great deal has changed in our brains.
* Grice’s point was, or should have been, that human communicators have the competence to exploit these features - and the competence to avoid being exploited by others exploiting these features. The acquisition of a language and memes in general is like the installation of a software app like Photoshop, with many layers that most amateur users never encounter. With human communication, there is much variation, and most uses of the system are rudimentary, routine, guided by habits that are themselves beneath the ken of most observers (and self-observers). But the tools admit of some very sophisticated applications. Some people are natural manipulators, impression creators, masters of indirection and almost subliminal blandishment, and others are bluff, direct, naive, unguarded in their speech - novice users of the tools - but neither kind of people have to comprehend the reasons why their everyday communication tools have all the options that they do.
* Some people, especially high-functioning people on the autism spectrum manages to devise, with much effort and ingenuity, a genuine theory of mind (TOM), to help them interpret the kaleidoscopic social world that most of uscan “perceive directly”.
* If Grice’s theory was a performance theory, it would be applicable to a small minority of speakers.
* The free-floating rationale of the design of some of our practices is unimagined by us. Grice can be seen to have worked it our, seen the “order which is there” when people engage in nonnatural meaning, and simply presented it as an account of their intentional states at the time - overendowing people with reasons!

== Part III: Turning Our Minds Inside Out ==
=== 13. Consciousness as an Evolved User-Illusion ===
=== 14. The Age of Post-Intelligent Design ===
[[Category:Consciousness]]
[[Category:Books]]

Atomic Habits

2025-04-13T10:30:52Z

Rob:

== Fundamentals ==
* You don’t rise to the level of your goals, you fall to the level of your systems.
* Three levels of change: outcome change, process change, identity change.
* Focus not on what you want to achieve, but on who you want to become.
* Your identity emerges out of your habits. Every action is a vote for the type of person you want to become.
* Becoming your best self requires you to continually edit your beliefs, and to upgrade and expand your identity.
* A habit is a behavior that has been repeated enough times to become automatic. The process of habit forming begins with trial and error. Neurological activity is high during this period. You are carefully analyzing the situation and making conscious decisions about how to act. You’re taking in tons of information and trying to make sense of it all. the brain is busy learning the most effective course of action.
* With prctice, the useless movements fade away and the useful actions get reinforced. Whenever you face a problem repeatedly, your brain begins to automate the process of solving it. Your habits are just a series of automatic solutions that solve the problems and stresses you face regularly.
* As habits are created, the level of brain activity decreases.
* Rewards teach us which actions are worth remembering in the future. Your brain is a reward detector - your sensory nervous system is continuously monitoring which actions satisfy your desires and deliver pleasure. Rewards close the feedback loop and complete the habit cycle.
== The First Law: Make It Obvious ==
* When you experience something repeatedly, like a paramedic seeing the face of a heart attack patient or a military analyst seeing a missile on a radar screen, your brain begins noticing what is important, sorting through the details and highlighting the relative cues, cataloging that information for future use. After a while you do this unconsciously.
* Jung: Until you make the unconscious conscious, it will direct your life and you will call it fate.
* Pointing and calling raises your level of awareness from a non-conscious habit to a more conscious level by verbalizing your actions
* Use the Habits Scorecard to become more aware of your habits
== The Second Law:Make It Attractive ==

== The Third Law: Make It Easy ==

== The Fourth Law: Make it Satisfying ==

== Advanced Tactics ==

[[Category:Consciousness]]
[[Category:Books]]

The Village of Eight Graves

2025-04-13T10:10:35Z

Rob:

Hmm. I think I’m out. There is some decent plotting here, but the murderer seemed obvious to me from quite early on and the motive (and means) are not very credible. The limestone caves are an interesting decor, but not well exploited and the constant gothic drama gets tedious.

[[Category:Books]]

Das Ludwig Thoma Komplott

2025-04-13T10:09:49Z

Rob: Created page with " Category:Books"

[[Category:Books]]

Atomic Habits

2025-04-13T10:09:20Z

Rob: Created page with " Category:Consciousness Category:Books"

[[Category:Consciousness]]
[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-13T10:08:43Z

Rob:

== Where is My Mind? ==

* By one estimate, the average American is exposed to 34GB (or 11.8hr) of information a day
* Hermann Ebbinghaus “On Memory: A contribution to Experimental Psychology (1885) - tried to memorize trigrams, established the idea of a forgetting curve over time.
* In essence, neurons function like a democracy with alliances or “cell assemblies”.
* Somewhere is the brain’s speech centers a large coalition of neurons cases votes for “bath”, a smaller coalition votes for “path”, and an even smaller minority votes for other candidates. Within less than half a second, the vote is tallied, and ultimately the baby picks up that it is time for a bath. The connections between the neutaons that supported bath are strengthened, and connections with neurons that voted for the wrong sound are weakened. As those neurons settle into coalitions that differentiate between the sound the baby is hearing, they are becoming less sensitive to sound differences that don’t exist in that language. It’s as if the neurons are choosing between a small number of candidates based on a few key issues.
* The connections in your brain are constantly being reshaped with the goal of improving your perception, movement, and thinking as you gain more and more experiences. Moreover, as you go past simple perception (what we see, hear, touch, taste, and smell) and move into higher-order functions (eg judgement, evaluation, and problem-solving), the brain is remarkably plastic, and the neural elections are highly contested.
* Interference - there is an intense competition between the coalition that has the memory you’re looking for and coalitions representing other memories you don’t need at that moment.
* The memories that are the most distinctive are the easiest to remember because they stand out relative to everything else.
* Attention - is our brain’s way of prioritizing what we are seeing, hearing, and thinking about.
* Intention - guide’s your attention to lock on to something specific.
* The prefrontal cortex:
** I the “central executive” of the brain. Several regions all over the brain have relatively specialized functions, and the job of the prefrontal cortex is to serve as a central executive, coordinating activity across these networks in the service of the mutual aim.
** Helps us learn with attention
** Takes up about a third of the real estate in the human brain
** Frontal lobotomy - removal of the prefrontal cortex - but rather than treating any underlying mental illness, it leaves patients in a zombielike state, apathetic, docile, and devoid of motivation.
** The more numbers people had to keep in mind, the more activity was apparent in the prefrontal cortex - it plays a part in temporarily holding information.
** People without a functioning prefrontal cortex could do fine when they were given clear instructions and no distractions, but they struggled when they had to spontaneously use memory strategies or follow through on a task when irrelevant things competed for their attention.
** Is intensively activated when a person had to use intention to stay on task, focus on distinctive information, resist distractions, or initiate some kind of mnemonic strategy.
** ADHD is associated with atypical activity in the prefrontal cortex.
** As we get older, we can still learn, but we have more trouble focusing on the details we want to take in and we often end up learning things that might be irrelevant.
** Certain part of the prefrontal cortex are thinned out, on average, in people who do heavy media multitasking.
* Use intention to guide our attention so we can remember what matters. Balance the needs of the experiencing self and the remembering self.

== Travelers of Time and Space ==
* We often think about memory as a record of what happened, but the human brain has the remarkable capability to link up the “what” with the where, when, and how. This explains why the experience of remembering is so often accompanied by an ephemeral sense of pastness that’s almost impossible to put into words. It’s also why, if we are in the right place at the right time, lost memories seem to find us.
* That sense of being in a particular time and place is called context, and it is critical for our day-to-day memory experiences. A great deal of everyday forgetting happens not because our memories have disappeared but because we can’t find our way back to them. In the right context, however, memories that have seemed long gone can suddenly resurface back to the forefront of our recall.
* Endel Tulving, in 1972, coined the term “episodic memory” to differentiate from “semantic memory”. To remember an event (episodic memory), we need to mentally return to a specific place and time; but to have knowledge (semantic memory), we need to be able to use what we previously learned across a range of contexts.
* For Tulving remembering puts us in a state of consciousness in which we feel as if we were transported to the past. A key characteristic of human consciousness is that we are “capable of mental time travel, roaming at will over what has happened as readily as over what might happen, independently of the physical laws that govern the universe.”
* You can confidently pull up facts about Paris (semantic memory) and vividly reexperience a trip to Paris (episodic memory), yet the two experiences are totally different.
* AIs have problems with “catastrophic forgetting”, where they learn a rule and then an exception to the rule makes them then throw away everything they had learnt around that rule to date. But we have episodic memory, which is not designed to capture the common elements of all our experiences; it stores and indexes every event differently, so you don’t get mixed up when you learn the exception to the rule.
* The neocortex works like a traditional neural network, enabling us to pick up facts, while the hippocampus is responsible for the brain’s amazing ability to rapidly create new memories for events.
* Brenda Milner, in 1957, published a paper about Patient H.M., Henry Molaison who had his seizures treated by removing about 5cm of tissue from the left and right hippocampus. Milner’s paper definitively linked the formation of new memories to the hippocampus.
* Ranganath suggested that the pattern of light and dark pixels identified by fMRI might be a unique configuration acting as a pointer to a particular memory like a QR code. When thinking about two separate episodic memories about the same person, the neocortex seemed to store the general facts about who and what were in the event, while in the hippocampus, the memory codes for the two related events looked totally different.
* The cell assemblies that allow us to remember particular parts of an event are in separate areas of the brain that normally do not talk to one another. The only thing they have in common is that they were active around the same time. The hippocampus, however, has connections to many of these areas, and its job is to store links to the different cell assemblies that come to life at a given moment. If you revisit the place, then the hippocampus would help reactivate all those cell assemblies, enabling you to reexperience seeing your friend. The hippocampus enables us to “index” memories for different events according to when and where they happened, not according to what happened. Because it organizes memories according to the context, recalling something from one event makes it easier to retrieve other events that happened around the same time or place, painting a fuller picture.
* Pulling up a memory of the recent past helps to ground you in the here and now. According to one prominent theory, episodic memory emerged in evolution from the more basic ability to learn where we are in the world.
* Sea lions without a functioning hippocampus grow disoriented. Lost, and unable to recall their foraging sites, they become malnourished and ultimately stranded onshore.
* The hippocampus is one of the first areas of the brain ravaged by Alzheimer’s, and this is probably why patients in the early stages frequently get lost and lost track of the passage of time. You see the look of fear on a face when a patient becomes unmoored from their sense of when and where they are in the world, like treading water in the open ocean.
* All the external factors from our environment, along with the motivations, thoughts, and feelings that characterize our internal world, come together to form the unique context that envelops our experience at any given time. When we access a particular episodic memory, we can pull up a bit of that past mental state, too.
* Two events that occurred close together in time are going to have more contextual elements in common than events that occurred further apart in time.
* Place, smells, tastes, and music are all powerful cues for episodic memories.
* Our emotions also contribute to context, which means that our feelings in the present affect what we can recall from the past. When we get angry, it’s easy to pull up all those memories that give us more reasons to be annoyed, and it’s harder to access the memories that don’t.
* The essential trick performed by the hippocampus is that it takes in information about the things in which we are interested, and it ties it up with information about the context, all the other stuff that’s going on in the background. We experience zillions of repetitive events, but the context makes each unique, and we can use context as a lifeline to find our way back to those things we seem to always lose.
* The further back in time you try to go, the harder it is for your brain to pull up a past context, and in some cases you won’t be able to do it. Science backs infantile amnesia where you can’t have episode memories before the age of two because the hippocampus is still developing and the entire neocortex is being massively reorganized.
* Event boundaries. We naturally update our sense of context when we experience a shift in our perception of the world around us, and those points mark the boundary between one event and another. People are better at remembering information that occurred at an event boundary then they are at remembering information from the middle of the event, and this is because the hippocampus waits to store a memory for an event until right after an event boundary - so we only encode the memory once we have a full understanding of the event.
** Event boundaries happen all the time and don’t necessarily require a change in location. Anything that alters your sense of the current context - a shift in the topic of conversation, a change in your immediate goals, or the onset of something surprising - can lead you to put up an event boundary.
* During the Covid epidemic, confined to home and with few event boundaries to provide meaningful structure to their lives, millions of people all over the world felt as if they were living in the twilight zone, floating aimlessly through time and space.
* Nostalgia - on average, people find it easier to recall positive experiences than negative ones, and this positivity bias increases as we get older, which might explain older adults’ penchant for nostalgia.
** The reminiscence bump - when we look back at the past, we tend to focus on a specific period of our lives, between the ages of ten and thirty - something about listing to a song or watching a movie from those formative years can give us a sense of meaning, connecting us to an idealized sense of who we are.
** The cost of nostalgia is that it can leave us feeling disconnected from our lives in the present, giving us a sense that things aren’t as they were in the “good old days”.
* Rumination - is the evil twin of nostalgia, and a prime example of how not to use episodic memory.

[[Category:Consciousness]]
[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-13T10:08:18Z

Rob:

[[Category:Consciousness]]
[[Category:Books]]

== Where is My Mind? ==

* By one estimate, the average American is exposed to 34GB (or 11.8hr) of information a day
* Hermann Ebbinghaus “On Memory: A contribution to Experimental Psychology (1885) - tried to memorize trigrams, established the idea of a forgetting curve over time.
* In essence, neurons function like a democracy with alliances or “cell assemblies”.
* Somewhere is the brain’s speech centers a large coalition of neurons cases votes for “bath”, a smaller coalition votes for “path”, and an even smaller minority votes for other candidates. Within less than half a second, the vote is tallied, and ultimately the baby picks up that it is time for a bath. The connections between the neutaons that supported bath are strengthened, and connections with neurons that voted for the wrong sound are weakened. As those neurons settle into coalitions that differentiate between the sound the baby is hearing, they are becoming less sensitive to sound differences that don’t exist in that language. It’s as if the neurons are choosing between a small number of candidates based on a few key issues.
* The connections in your brain are constantly being reshaped with the goal of improving your perception, movement, and thinking as you gain more and more experiences. Moreover, as you go past simple perception (what we see, hear, touch, taste, and smell) and move into higher-order functions (eg judgement, evaluation, and problem-solving), the brain is remarkably plastic, and the neural elections are highly contested.
* Interference - there is an intense competition between the coalition that has the memory you’re looking for and coalitions representing other memories you don’t need at that moment.
* The memories that are the most distinctive are the easiest to remember because they stand out relative to everything else.
* Attention - is our brain’s way of prioritizing what we are seeing, hearing, and thinking about.
* Intention - guide’s your attention to lock on to something specific.
* The prefrontal cortex:
** I the “central executive” of the brain. Several regions all over the brain have relatively specialized functions, and the job of the prefrontal cortex is to serve as a central executive, coordinating activity across these networks in the service of the mutual aim.
** Helps us learn with attention
** Takes up about a third of the real estate in the human brain
** Frontal lobotomy - removal of the prefrontal cortex - but rather than treating any underlying mental illness, it leaves patients in a zombielike state, apathetic, docile, and devoid of motivation.
** The more numbers people had to keep in mind, the more activity was apparent in the prefrontal cortex - it plays a part in temporarily holding information.
** People without a functioning prefrontal cortex could do fine when they were given clear instructions and no distractions, but they struggled when they had to spontaneously use memory strategies or follow through on a task when irrelevant things competed for their attention.
** Is intensively activated when a person had to use intention to stay on task, focus on distinctive information, resist distractions, or initiate some kind of mnemonic strategy.
** ADHD is associated with atypical activity in the prefrontal cortex.
** As we get older, we can still learn, but we have more trouble focusing on the details we want to take in and we often end up learning things that might be irrelevant.
** Certain part of the prefrontal cortex are thinned out, on average, in people who do heavy media multitasking.
* Use intention to guide our attention so we can remember what matters. Balance the needs of the experiencing self and the remembering self.

== Travelers of Time and Space ==
* We often think about memory as a record of what happened, but the human brain has the remarkable capability to link up the “what” with the where, when, and how. This explains why the experience of remembering is so often accompanied by an ephemeral sense of pastness that’s almost impossible to put into words. It’s also why, if we are in the right place at the right time, lost memories seem to find us.
* That sense of being in a particular time and place is called context, and it is critical for our day-to-day memory experiences. A great deal of everyday forgetting happens not because our memories have disappeared but because we can’t find our way back to them. In the right context, however, memories that have seemed long gone can suddenly resurface back to the forefront of our recall.
* Endel Tulving, in 1972, coined the term “episodic memory” to differentiate from “semantic memory”. To remember an event (episodic memory), we need to mentally return to a specific place and time; but to have knowledge (semantic memory), we need to be able to use what we previously learned across a range of contexts.
* For Tulving remembering puts us in a state of consciousness in which we feel as if we were transported to the past. A key characteristic of human consciousness is that we are “capable of mental time travel, roaming at will over what has happened as readily as over what might happen, independently of the physical laws that govern the universe.”
* You can confidently pull up facts about Paris (semantic memory) and vividly reexperience a trip to Paris (episodic memory), yet the two experiences are totally different.
* AIs have problems with “catastrophic forgetting”, where they learn a rule and then an exception to the rule makes them then throw away everything they had learnt around that rule to date. But we have episodic memory, which is not designed to capture the common elements of all our experiences; it stores and indexes every event differently, so you don’t get mixed up when you learn the exception to the rule.
* The neocortex works like a traditional neural network, enabling us to pick up facts, while the hippocampus is responsible for the brain’s amazing ability to rapidly create new memories for events.
* Brenda Milner, in 1957, published a paper about Patient H.M., Henry Molaison who had his seizures treated by removing about 5cm of tissue from the left and right hippocampus. Milner’s paper definitively linked the formation of new memories to the hippocampus.
* Ranganath suggested that the pattern of light and dark pixels identified by fMRI might be a unique configuration acting as a pointer to a particular memory like a QR code. When thinking about two separate episodic memories about the same person, the neocortex seemed to store the general facts about who and what were in the event, while in the hippocampus, the memory codes for the two related events looked totally different.
* The cell assemblies that allow us to remember particular parts of an event are in separate areas of the brain that normally do not talk to one another. The only thing they have in common is that they were active around the same time. The hippocampus, however, has connections to many of these areas, and its job is to store links to the different cell assemblies that come to life at a given moment. If you revisit the place, then the hippocampus would help reactivate all those cell assemblies, enabling you to reexperience seeing your friend. The hippocampus enables us to “index” memories for different events according to when and where they happened, not according to what happened. Because it organizes memories according to the context, recalling something from one event makes it easier to retrieve other events that happened around the same time or place, painting a fuller picture.
* Pulling up a memory of the recent past helps to ground you in the here and now. According to one prominent theory, episodic memory emerged in evolution from the more basic ability to learn where we are in the world.
* Sea lions without a functioning hippocampus grow disoriented. Lost, and unable to recall their foraging sites, they become malnourished and ultimately stranded onshore.
* The hippocampus is one of the first areas of the brain ravaged by Alzheimer’s, and this is probably why patients in the early stages frequently get lost and lost track of the passage of time. You see the look of fear on a face when a patient becomes unmoored from their sense of when and where they are in the world, like treading water in the open ocean.
* All the external factors from our environment, along with the motivations, thoughts, and feelings that characterize our internal world, come together to form the unique context that envelops our experience at any given time. When we access a particular episodic memory, we can pull up a bit of that past mental state, too.
* Two events that occurred close together in time are going to have more contextual elements in common than events that occurred further apart in time.
* Place, smells, tastes, and music are all powerful cues for episodic memories.
* Our emotions also contribute to context, which means that our feelings in the present affect what we can recall from the past. When we get angry, it’s easy to pull up all those memories that give us more reasons to be annoyed, and it’s harder to access the memories that don’t.
* The essential trick performed by the hippocampus is that it takes in information about the things in which we are interested, and it ties it up with information about the context, all the other stuff that’s going on in the background. We experience zillions of repetitive events, but the context makes each unique, and we can use context as a lifeline to find our way back to those things we seem to always lose.
* The further back in time you try to go, the harder it is for your brain to pull up a past context, and in some cases you won’t be able to do it. Science backs infantile amnesia where you can’t have episode memories before the age of two because the hippocampus is still developing and the entire neocortex is being massively reorganized.
* Event boundaries. We naturally update our sense of context when we experience a shift in our perception of the world around us, and those points mark the boundary between one event and another. People are better at remembering information that occurred at an event boundary then they are at remembering information from the middle of the event, and this is because the hippocampus waits to store a memory for an event until right after an event boundary - so we only encode the memory once we have a full understanding of the event.
** Event boundaries happen all the time and don’t necessarily require a change in location. Anything that alters your sense of the current context - a shift in the topic of conversation, a change in your immediate goals, or the onset of something surprising - can lead you to put up an event boundary.
* During the Covid epidemic, confined to home and with few event boundaries to provide meaningful structure to their lives, millions of people all over the world felt as if they were living in the twilight zone, floating aimlessly through time and space.
* Nostalgia - on average, people find it easier to recall positive experiences than negative ones, and this positivity bias increases as we get older, which might explain older adults’ penchant for nostalgia.
** The reminiscence bump - when we look back at the past, we tend to focus on a specific period of our lives, between the ages of ten and thirty - something about listing to a song or watching a movie from those formative years can give us a sense of meaning, connecting us to an idealized sense of who we are.
** The cost of nostalgia is that it can leave us feeling disconnected from our lives in the present, giving us a sense that things aren’t as they were in the “good old days”.
* Rumination - is the evil twin of nostalgia, and a prime example of how not to use episodic memory.

[[Category:Consciousness]]
[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-13T09:58:03Z

Rob: /* Travelers of Time and Space */

Why We Remember: Revealing the Hidden Power of Memory

2025-04-13T08:17:47Z

Rob:

Books

2025-04-13T08:12:10Z

Rob:

== Books to Buy ==

* Language, Thought, and other Biological Categories
* The Flat Mind
* On the Calculation of Volume - Solvej Balle
* Open Socrates - Agnes Callard
* Why Machines Learn: The Elegant Maths Behind Modern AI (out in paperback Jan 30 2025)
* A History of the Muslim World: From Its Origins to the Dawn of Modernity (awaiting paperback)
* How Life Works: A User’s Guide to the New Biology
* Stranger Than Fiction: Lives of the Twentieth-Century Novel
* Grey Matters: A Biography of Brain Surgery - not yet in paperback
* The New Roman Empire: A History of Byzantium
* Magnetic Mountain: Stalinism as Civilization
* Consolations - David Whyte

== Books to Read ==

* Reading to Learn - William Zinger
* Breakfast of Champions - Kurt Vonnegut
* A Little History of Philosophy - Nigel Warburton

== Currently Reading ==

* [[From Bacteria to Bach and Back]] - Daniel Dennett (re-read)
* [[Why We Remember: Revealing the Hidden Power of Memory]] - Dr Charan Ranganath
* [[Atomic Habits]] - James Clear
* [[Das Ludwig Thoma Komplott]]- Sabine Vöhringer

== Books Read ==

=== 2025 ===

* [[The Village of Eight Graves]] - Seishi Yokomizo
* [[Science: A History]] - Richard Crockett
* [[Vienna: How the City of Ideas Created the Modern World]] - John Gribbin
* [[The Inugami Curse]] - Seishi Yokomizo
* [[The Rise and Reign of the Mammals]]
* [[Four Ways of Thinking]] - David Sumpter
* [[I've Been Thinking]] - Daniel Dennett
* [[Serendipities: Language and Lunacy]] - Umberto Eco
* [[I Am Dynamite: A Life of Friedrich Nietzsche]] - Sue Prideaux
* [[A Brief History of Intelligence]] - Max S. Bennett
* [[Foucault’s Pendulum]] - Umberto Eco (re-read)
* [[Kant and the Platypus]] - Umberto Eco
* [[Le cerveau m’a beaucoup déçu. L’esprit, non]] - Antoine Sénanque

=== 2024 ===

* The Plot - Will Eisner
* The Prague Cemetery - Umberto Eco
* The Nonjin Murders - Seishi Yokomizo
* When We Cease to Understand the World - Labatut
* Zen and the Art of Motorcycle Maintenance - Robert Pirsig (reread)
* The Way We Think: Conceptual Blending and the Mind’s Hidden Complexities - Fauconnier and Turner
* The Singularity is Nearer - Ray Kurzweil
* Physics and Philosophy - Werner Heisenberg
* Le Ton Beau de…
* The Origins of Creativity - Edward O Wilson
* Psychonauts -
* The MANIAC - Benjamin Labatut
* In Search of Memory - Eric R. Kandel
* Dreaming: A Very Short Introduction - Hobson
* Les Effinger - Gabriele Target
* Triad - Tom Keve
* Nietzsche - Stefan Zweig
* The Weirdest People in the World - Joseph Henrich
* How Language Works - David Crystal
* The Invention of Nature - Andrea Wolf
* The Song of the Cell - Siddhartha Mukherjee
* [[Gödel, Escher, Bach]] - Douglas Hofstadter
* [[From Bacteria to Bach and Back]] - Daniel Dennett

[[Category:Books]]

Books

2025-04-13T08:06:12Z

Rob: /* Books to Read */

== Books to Buy ==

* Language, Thought, and other Biological Categories
* The Flat Mind
* On the Calculation of Volume - Solvej Balle
* Open Socrates - Agnes Callard
* Why Machines Learn: The Elegant Maths Behind Modern AI (out in paperback Jan 30 2025)
* A History of the Muslim World: From Its Origins to the Dawn of Modernity (awaiting paperback)
* How Life Works: A User’s Guide to the New Biology
* Stranger Than Fiction: Lives of the Twentieth-Century Novel
* Grey Matters: A Biography of Brain Surgery - not yet in paperback
* The New Roman Empire: A History of Byzantium
* Magnetic Mountain: Stalinism as Civilization
* Consolations - David Whyte

== Books to Read ==

* Why we remember
* Reading to Learn - William Zinger
* Breakfast of Champions - Kurt Vonnegut
* A Little History of Philosophy - Nigel Warburton

== Currently Reading ==

== Books Read ==

=== 2025 ===

* [[From Bacteria to Bach and Back]] - Daniel Dennett (re-read)
* [[Why We Remember: Revealing the Hidden Power of Memory]] - Dr Charan Ranganath
* [[The Village of Eight Graves]] - Seishi Yokomizo
* [[Science: A History]] - Richard Crockett
* [[Vienna: How the City of Ideas Created the Modern World]] - John Gribbin
* [[The Inugami Curse]] - Seishi Yokomizo
* [[The Rise and Reign of the Mammals]]
* [[Four Ways of Thinking]] - David Sumpter
* [[I've Been Thinking]] - Daniel Dennett
* [[Serendipities: Language and Lunacy]] - Umberto Eco
* [[I Am Dynamite: A Life of Friedrich Nietzsche]] - Sue Prideaux
* [[A Brief History of Intelligence]] - Max S. Bennett
* [[Foucault’s Pendulum]] - Umberto Eco (re-read)
* [[Kant and the Platypus]] - Umberto Eco
* [[Le cerveau m’a beaucoup déçu. L’esprit, non]] - Antoine Sénanque

=== 2024 ===

* The Plot - Will Eisner
* The Prague Cemetery - Umberto Eco
* The Nonjin Murders - Seishi Yokomizo
* When We Cease to Understand the World - Labatut
* Zen and the Art of Motorcycle Maintenance - Robert Pirsig (reread)
* The Way We Think: Conceptual Blending and the Mind’s Hidden Complexities - Fauconnier and Turner
* The Singularity is Nearer - Ray Kurzweil
* Physics and Philosophy - Werner Heisenberg
* Le Ton Beau de…
* The Origins of Creativity - Edward O Wilson
* Psychonauts -
* The MANIAC - Benjamin Labatut
* In Search of Memory - Eric R. Kandel
* Dreaming: A Very Short Introduction - Hobson
* Les Effinger - Gabriele Target
* Triad - Tom Keve
* Nietzsche - Stefan Zweig
* The Weirdest People in the World - Joseph Henrich
* How Language Works - David Crystal
* The Invention of Nature - Andrea Wolf
* The Song of the Cell - Siddhartha Mukherjee
* [[Gödel, Escher, Bach]] - Douglas Hofstadter
* [[From Bacteria to Bach and Back]] - Daniel Dennett

[[Category:Books]]

From Bacteria to Bach and Back

2025-04-12T16:40:56Z

Rob: /* 12. The Origins of Language */

== Part I: Turning Our World Upside Down ==
=== 1. Introduction ===
* How come there are minds?
** Minds evolved and created thinking tools that eventually enabled minds to know how minds evolved, and even to know how these tools enabled them to know what minds are.
** What thinking tools? The simplest, on which all the others depend in various ways, are spoken words, followed by reading, writing, and arithmetic, followed by navigation and mapmaking, apprenticeship practices, and all the concrete devices for extracting and manipulating information that we have invented: compass, telescope, microscope, camera, computer, the Internet, and so on.
** These, in turn, fill our lives with technology and science, permitting us to know many things not known by other species. We know there are bacteria. Even bacteria don't know there are bacteria.
** Our minds are different. It takes thinking tools to understand what bacteria are, and we're the only species (so far) endowed with an elaborate kit of thinking tools.
* A birds-eye view of the journey:
** Life has been around on Earth for around 4bn years. The first 2bn were spent optimizing the machinery for self-maintenance, energy acquisition and reproduction, and the only living things were relatively simple, single-celled entities - bacteria or their cousins, archaea: the prokaryotes.
** Then an amazing thing happened. Two different prokaryotes collided and instead of one eating the other, it let it go on living, and, by dumb luck, found itself fitter, more competent in some way that mattered, than it had been before. This was perhaps the first successful instance of technology transfer. A fortuitous mutation almost never happens, but evolution depends on those rarest of rare events. This is the birth of the eukaryotes
** Every living thing big enough to be visible to the naked eye is a multicellular eukaryote.
** The Cambrian Explosion, which occurred over several million years about 530m ya, saw the sudden arrival of a bounty of new life forms.
** The "MacCready Explosion", at the dawn of human agriculture, about 10k ya, transformed the terrestrial vertebrate biomass (excluding insects, other invertebrates, and marine animals). At the beginning, humans plus their livestock and pets make up only 0.1%, and now we make up 98% (mostly cattle). This explosion is based on three factors - population, technology, and intelligence (our so-called native intelligence depends on both our technology and our population numbers).
* Dennett identified the "romantic" and "killjoy" sides of the duel over the stature of animal minds. We are not the God-like geniuses we think we are, but animals are not so smart either, and yet both humans and other animals are admirably equipped to deal "brilliantly" with many of the challenges thrown at them.

=== 2. Before Bacteria and Bach ===
* until there were systems that could be strictly called reproducing systems, the processes at work were only proto-evolutionary, semi-Darwinian, partial analogues of proper evolution by natural selection; they were processes that raised the likelihood that various combinations of ingredients would arise and persist, concentrating the feedstock molecules until this eventually led to the origin of life.
* A living thing must capture enough energy and materials, and fend off its own destruction long enough to construct a good enough replica of itself.
* The reverse-engineering perspective is ubiquitous in biology and is obligatory in investigations of the origin of life. It always involves some kind of optimality considerations: What is the simplest chemical structure that could possibly do x? Or would phenomenon x be stable enough to sustain process y?
* Orgel's second rule: "Evolution is cleverer than you are."
* Here is an example of a possible gambit in the origin of life:
** It is tempting to assume that the very first living thing capable of reproducing must have been the simples possible living thing (given the existing conditions on the planet at the time).
** Make the simples replicator you can imagine and then build on that foundation.
** But this is by no means necessary. It is possible, and more likely, I think, that a rather inelegantly complicated, expensive, slow, Rub-Goldberg conglomeration of objets trouvés was the first real replicator, and after it got the replication ball rolling, this ungainly replicator was repeatedly simplified in competition with its kin.
** Many of the most baffling magic tricks depend on the audience no imagining the ridiculously extravagant lengths magicians will go to in order to achieve a baffling effect. If you want to reverse-engineer magicians, you should always remind yourself that they have no shame, no abhorrence of bizarre expenditures for tiny effects that they can then exploit. Nature, similarly, has no shame - and no budget, and all the time in the world.
* [[Adaptionism]] is alive and well; reverse-engineering is still the royal road to discovery in biology.

=== 3. On the Origin of Reasons ===
* There are three strategies to adopt when trying to understand, explain, and predict phenomena:
** The physical stance - is the least risky but also the most difficult; you treat the phenomenon as obeying the laws of physics, and use physics to predict what will happen next.
** The design stance - is only for things that have been designed, either artifacts or living things or their parts, and have functions or purposes.
** The intentional stance - works primarily for things that are designed to use information to accomplish their functions. It works by treating the thing as a rational agent, attributing "beliefs" and "desires" and "rationality" to the thing, and predicting that it will act rationally.
* Evolution by natural selection is not itself a designed thing, an agent with purposes, but it acts as if it were. It is a set of processes that "find" and "track" reasons for things to be arranged one way rather than another.
* The reasons found by human designers are typically (but not always) represented in the minds of the designers, whereas the reasons uncovered by natural selection are represented for the first time by those human investigators who succeed in reverse-engineering Nature's productions.
* Our human world of reasons grew out of a world where there were no reasons.
* Two meanings of the word "why":
** What for - "Why are you handing me your camera?"
** How come - "Why does ice float?" This is asking for a cause or a process narrative
* Evolution by natural selection starts with "how come" and arrives at "what for". We start with a lifeless world in which there are no reasons, no purposes at all, but there are processes that happen.
* A central feature of human interaction, and one of the features unique to our species, is the activity of asking others to explain themselves, to justify their choices and actions, and then judging, endorsing, rebutting their answers, in recursive rounds of the "why?" game.
* Our capacity to respond appropriately in this reason-checking activity is the root of responsibility. Those who cannot explain themselves or cannot be moved by the reasons offered by others, those who are "dead to" the persuasions of advisors, are rightly judges to be of diminished responsibility and are treated differently by the law.
* The "logical space of reasons" is bound by norms, by mutual recognition of how things ought to go. Wherever there are reasons, there is room and need for some kind of justification and the possibility of correction when something goes wrong. This normativity is the foundation of ethics.
* But there are two kinds of norms and corrections:
** social normativity - concerned with social norms, practice, and collaboration
** instrumental normativity - concerned with quality control or efficiency, the norms of engineering
* Natural selection is an algorithmic process, a collection of sorting algorithms that are themselves composed of generate-and-test algorithms.
* In the prebiotic or abiotic world (before life), there were cycles at many spatio-temporal scales: seasons, night and day, tides, the water cycle, and thousands of chemical cycles discoverable at the atomic and molecular level, gradually changing the conditions in the world and thus raising the probability that something new will happen.
* This led to differential persistence, some temporary combinations of parts hang around longer than others. The rich can get richer, even though they can't yet bequeath their riches to descendants.
* Differential persistence must then somehow gradually turn into differential reproduction.
* "Serendipity" is when something good happens randomly, while "clobbering" is when something bad happens randomly.
* Walls or membranes that are randomly persisted are serendipitous in that they allow internal cycles to operate for a time without interference, and we see the engineering necessity of membranes to house the collection of chemical cycles - the Krebs cycle and thousands of others - that together permit life to emerge.
* Before we can have competent reproducers, we have to have competetent persisters. We are witnessing an automatic (algorithmic) paring away of the nonfunctional, crowded out by the functional.
* There are reasons why the parts are shaped and ordered as they are and this is the birth of reasons. Through Darwinism about Darwinism, we see the gradual emergence of the species of reasons out of the species of mere causes, what fors out of how comes*
* Natural selection is an automatic reason-finders, which "discovers" and "endorses" and "focuses" reasons over many generations.
* If there happens to be a "difference that happens to make a difference" then we have the germ of a reason, a proto-reason, and when this is selected to persist longer, then we can see emerge the accumulation of function by a process that blindly tracks reasons.
* Reasons existed before there were reasoners. There are reasons why trees spread their branches but they are not, in any strong sense, the trees' reasons. They don't "have" the reasons and they don't need to have the reasons.
* Darwin didn't extinguish teleology - he naturalized it.
* Reverse-engineering in biology is a descendant of reason-giving-judging.
* The evolution of what for from how come can be seen in the way we interpret the gradual emergence of living things via a cascade of prebiotic cycles. Free-floating rationales emerge as the reasons why some features exist; they do not presuppose intelligent designers, even though the designs that emerge are extraordinarily good.

=== 4. The Strange Inversions of Meaning ===
* The world before Darwin was held together not by science but by tradition, through the trickle-down theory of creation from God, which Darwin replaced by the bubble-up theory of creation.
* Design space:
** Skyhooks - float high in design space, unsupported by ancestors, the direct result of a special act of intelligent creation.
** Cranes - are non-miraculous innovations in design space that enable ever more powerful lifting and efficient exploration of the space. Endosymbiosis is a crane, as are sex and language and culture.
* Turing showed that it was possible to design mindless machines that were absolutely ignorant, but that could do arithmetic perfectly, following "instructions" that could be mechanically implemented.
* This is "competence without comprehension" and Turing saw that it could provide a traversable path in design space from absolute ignorance to artificial intelligence.
* All the brilliance and comprehension in the world arises ultimately out of uncomprehending competences compounded over time into ever more competent - and hence comprehending - systems.
* This overthrows the pre-Darwinian mind-first vision of Creation with a mind-last vision.
* Darwin discovered evolution by natural selection, while Turing invented the computer, but he is one of the twigs on the Tree of Life who is, himself, an indirect product of the blind Darwinian processes.
* Distribution of expertise or understanding of this sort is a hallmark of human creative processes.
* "Ontology" is the set of "things" that an animal can recognize and behave appropriately with regard to, and equally the set of things that a computer program has to be able to deal with to do its job. Humans have extremely varied ontologies. Some believe in electrons and some believe in abominable snowmen, but there is a huge common core that is shared by all normal human beings from around 6 years old:
** Manifest image - the things we use in our daily lives to anchor our interactions and conversations. For every noun in our everyday speech, there is a kind of thing it refers to. It comes along with your native language. It's the world according to us
** Scientific image - populated with molecules, atoms, electrons, gravity, quarks. But even scientists spend most of their day in the manifest image.
* These two versions of the world that are now quite distinct were once merged or intertwined in a single ancestral world of "what everybody knows" that included all the local fauna and flora and weapons and tools and dwellings and social roles, but also goblins and gods and miasmas and spells.
* We can treat animals as having different ontologies without settling issues of whether they are conscious of them or simply the beneficiaries of designs that can be interpreted (by reverse engineers or forward engineers) as having those ontologies.
* A well designed elevator:
** Has a kind of ontology. It is a good elevator if it interacts appropriately with its environment and its passengers. It uses variables to keep track of all the features of the world that matter to getting its job done and is oblivious to everything else.
** It has no need to know what its ontology is or why - the rationale of the program is something only the program's designers have to understand.
** Its prudent self-monitoring can be seen to be an elementary step towards consciousness.
* Even bacteria are good at staying alive, at making the right moves at the right times, but they have elevator-type minds, not elevated minds like ours. And these minds are the products of an R&D process of trial and error that gradually structured their internal machinery to move from state to state in a way highly likely - not guaranteed - to serve their limited but vital interests.
* But unlike the elevator there is noting at all that plays the rols of the labels or comments in a source program. There is nothing anywhere at any time in that R1D history that represents the rationales of it. But they can be discovered by reverse engineering - there is a reason why the parts are shaped as they are, why the behaviors are organized as they are, and that reason will "justify" the design (or an earlier design that has now become either vestigial or transformed by further evolution to serve some newer function.
* The elevator has replaced a human - the elevator operator - by a machine that "sorta" follows the same rules as the human. We humans often occupy this kind of intermediate level of consciousness where we have internalized or routinized through practice a set of explicit rules that we may then discard and even forget.
* The Manhattan project had a small number of intelligent designers who organized a massive group of people, most of whom knew nothing about what they were doing beyond their immediate tasks. The "need to know" principle means that it is possible to create very reliable levels of high competence with almost no comprehension for rather insulated tasks
* GOFAI can be seen in retrospect as an exercise in creating something rather Cartesian, a rationalistic expert with myriads of propositions stored in its memory, and all the understanding incorporated in its ability to draw conclusion. It relied on the comprehension of the designers to contrive systems composed of subsystems that were foresightedly equipped with exactly the competences they would need in order to handle the problems they might face.
* But modern deep-learning AI is bottom-up, using wasteful, mindless, less bureaucratic, more evolution-like processes of information extraction.
* Top-down intelligent designing works, but it is responsible for much less of the design in our world than is commonly appreciated.
* Comprehension, far from being a Godlike talent from which all design must flow, is an emergent effect of systems of uncomprehending competence; natural selection on one hand, and mindless computation on the other.

=== 5. The Evolution of Understanding ===
* Human designers start with a goal (which may be refined or abandoned along the way) and work top-down, with the designers using everything they know to guide their search for solutions to the design problems they set for themselves.
* Evolution, in contrast, has no goals, no predefined problems, and no comprehension to bring to the task.
* How could a slow, mindless process build a thing that could build a thing that a slow mindless process couldn't build on its own? A process with no Intelligent Designer can create intelligent designers who then design things that permit us to understand how a process with no Intelligent Designer can create intelligent designers who then design those things.
* An organism's "umwelt" is the behavioral environment that consists of all the things that matter to its well-being.
* "Affordances" are the relevant opportunities in the environment of any organism: things to eat of mate with, openings to walk through or look out of, holes to hide in, things to stand on, and so forth.
* Organsims can be the beneficiaries of design features that imply ontologies without themselves representing those ontologies.
* Biology is reverse-engineering, and reverse-engineering is methodically committed to optimality considerations. Bacteria don't know they are bacteria, but they respond to other bacteria in bacteria-appropriate ways and are capable of avoiding or tracking or trailing things they distinguish in their umwelt.
* In software engineering, there is a reason why debugging cannot be completely automated: what counts as a bug depends on all the purposes (and sub and sub-sub-purposes) of the software, and specifying in sufficient detail what those purposes are is, at least for practical purposes, the very same task as writing debugged code in the first place!
* Design revision in Nature must follow the profligate method of releasing and test-driving many variants and letting the losers die, unexamined.
* Evolution explores the "adjacent possible".
* Natural selection is full of bugs. Organisms are filled with all-but-undecipherable "spaghettit code" of undisciplined programmers, but the free-floating rationale of the whole system is clearly good enough for practical purposes.
* When does comprehension emerge?
* We are right to adopt the intentional stance to understand the benefits derived from competences, but these competences can be provided by the machinery without any mentality intruding at all.
* We can say that organisms with spectacular competences but without comprehension, are "gifted".
* When there isn't enough stability over time in the selective environment to permit natural selection to "predict" the future accurately (when "selecting" the best designs for the next generation), natural selection does better by leaving the next generation's design partially unfixed. Learning can take over where natural selection left off, optimizing the individuals in their own lifetimes by extracting information from the world encountered and using it to make local improvements.
* Costly-signalling theory, where an animal does something to deceive or distract a predator does not need comprehension. These animals cannot choose to deceive, they simply do it automatically in certain circumstances due to a "knee-jerk reflex".
* Comprehension is not the source of competence or the active ingrediant in competence - instead, it is composed of competences.
* The illusion that understanding is some additional, separable mental phenomenon is fostered by the aha! phenomenon, or eureka effect.
* Comprehension comes in degrees, but even at the highest levels of competence, comprehension is never absolute. All comprehension is sorta comprehension from some perspective.
* We count on experts to have deep "complete" understanding of difficult concepts we rely on every day, only half-comprehendingly, and language is the capacity to transmit, faithfully, information we only sorta understand.
* The Beatrix Potter syndrome, or intentional stance towards animals works whether the rationales it adduces are free floating or explicitly represented in the midst of the agents we are predicting.
* Whatever is going on in the animal's brain has the competence to detect and respond appropriately to the information in the environment. But the intentional stance just gives the specs for the mind and leaves the implementation for later.
* We idealize everybody's thinking, and even our own access to reasons, blithely attributing phantom bouts of clever reasoning to ourselves after the fact. Asked "Why did you do that?", the most honest thing to say is often "I don't know, it just came to me," but we often succumb to the temptation to engage in whig history, not settling for how come but going for what for.
* Four grades of competence:
** Darwininian Creatures - Have predefined and fixed competences created by the R&D of evolution. They are born hard-wired, knowing all they will ever know, they are gifted but not learners.
** Skinnerian Creatures - Have, in addition, the ability to adjust their behavior in reaction to "reinforcement". They start out with some "plasticity". They more or less randomly generate new behaviors to test the world and those that get reinforced are more likely to recur in similar circumstances in the future.
** Popperian Creatures - Look before they leap. They extract information about the cruel world and keep it handy, so they can use it to pretest hypothetical behaviors offline. Eventually they must act in the real world, but their first choice is not random, having won the generate-and-test competition trial runs in the internal environment model. The "habit" of "creating forward models" of the world and using them to make decision and modulate behavior is a fine habit to have, whether or not you understand it.
** Gregorian Creatures - Their Umwelt is well stocked with thinking tools, both abstract and concrete. Only with them do we find the deliberate introduction and use of thinking tools, systematic exploration of possible solutions to problems, and attempts at higher-order control of mental searches. Only we human beings are Gregorian creatures, apparently.
* The smartest animals are not "just" Skinnerian creatures but Popperian creatures, capable of figuring out some of the clever things they have been observed to do. They engage in exploratory behavior. They need not know that this is the rationale for their behavior, but they benefit from it by reducing uncertainty. The fact that they don't understand the grounds of their own understanding is no barrier to calling it understanding, since we humans are often in the same ignorant state about how we manage to figure out novel things.
* Some animals, like us, have something like an inner workshop, a portable design-improvement facility.
* An unconscious mind is no longer seen as a contradiction in terms. The puzzle today is what is consciousness for (if anything)?
* Animals, plants, and even microorganisms are equipped with competences that permit them to deal appropriately with the affordances of their environments. There are free-floating rationales for all these competences, but the organisms need not appreciate or comprehend them to benefit from them, nor do they need to be conscious of them. In animals with more complex behaviors, the degree of versatility and variability exhibited can justify attributing a sort of behavioral comprehension to them so long as we don't make the mistake of thinking of comprehension as some sort of stand-alone talent, a source of competence rather than a manifestation of competence.

== Part II: From Evolution to Intelligent Design ==
=== 6. What is Information? ===
* Did the information age begin:
** When people began writing things down, drawing maps, and otherwise recording and transmitting valuable information they couldn't keep in their heads with high fidelity?
** When people began speaking and passing on accumulated lore, history, and mythology?
** Over 530m ya, when eyesight evolved during the Cambrian Era, triggering an arms race of innovation in behavior and organs that could respond swiftly to the information gathered from the light?
** When life began - even the simplest reproducing cells survived thanks to parts that functioned by discriminating differences in themselves and and their immediate surroundings?
* Dennett focuses on "Semantic Information", which is so important to us that we want to be able to use if effectively, store it without loss, move it, transform it, share it, hide it.
* Memory can be conceived as an information channel, just as subject to noise as any telephone line.
* Analog to digital converors (ADCs), are analogous to the sensitive cells that accomplish transduction on the out input edges of the nervous system, though the conversion in brains is not into bit strings, but neuronal spike trains.
* McCulloch and Pitts, in 1943, demonstrated the logical possibility of a general purpose representing-and-learning-and-controlling network made out of units that performed simple, nonmiraculous, clueless tasks - a comprehender of sorts made of merely competent parts.
* The brain is certainly not a digital computer running binary code, but it is still a kind of computer.
* Economic information is whatever is worth some work.
* Survival depends on information, on differential and asymmetric information: I know some things you don't know.
* Semantic information is design worth getting - design always involves R1D work of some kind, using available semantic information to improve the prospects of something by adjusting its parts in some appropriate way.
* One can actually improve one's design as an agent in the world by just learning useful facts. All learning, learning what and learning how, can be a valuable supplement or revision to the design you were born with.
* Semantic information is a distinction that makes a difference, a difference that makes a difference.
* Information in general is that which justifies representational activity, that which determines form.
* Misinformation and disinformation are dependent or even parasitic kinds of information. Disinformation is the designed exploitation of another agent's systems of discrimination, which themselves are designed to pick up useful information and use it.
* Most of what anybody knows is adaptively inert, but cheap to store, and the bits that do matter, really matter.
* Advertisers and propagandists seek to build "outposts of recognition" in other agents minds.
* In natural selection, R&D happens, designs are improved because they all have to "pay for themselves" in differential reproduction, and Darwinian lineages "learn" new tricks by adjusting their form. They are, then, in-formed, a valuable step up in local design space.
* In the same way, Skinnerian, Popperian, and Gregorian creatures inform themselves during their own lifetimes by their encounters with their environments, becoming ever more effective agents thanks to the information they can now use to do all manner of new things, including developing new ways of further informing themselves. The rich get richer. And the richer and richer, using their information to refine the information they use to refine the information they use to refine the information they obtain by the systems they design to improve the information available to them when they set out to design something.
* Useful information is a descendent of JJ Gibson's affordances.
* Information is that which is selected.
* What semantic information can be gleaned from an event depends on what information the gleaner already has accumulated.
* Offspring inherit a manifest image with an ontology of affordances from their parents and are born ready to distinguish the things that are most important to them.
* Evolution is all about turning bugs into features, and turning noise into signal
* Where does all the information in DNA come from? From the gradual, purposeless, nonmiraculous transformation of noise into signal, over billions of years.
* Information is always relative to what the receiver already knows.
* Remembering is not simply retrieving some thing that has been stored in some place in the brain.
* Don't acquire and maintain what doesn't pay for itself. More is not always better. Intentional mind-clearing or unlearning is not an unusual phenomenon.
* So much of the semantic information that streams into our heads each day is not worth getting.
* Within an organism the information-transmitting channels tend to be highly reliable.
* The brain's job in perception is to filter out, discard, and ignore all but the noteworthy features of the flux of energy striking one's sensory organs.
* Semantic information:
** Is valuable - misinformation and disinformation are either pathologies or parasitic perversions of the default cases.
** Its value is receiver-relative and not measurable in any nonarbitrary way but can be confirmed by empirical testing
** The amount carried or contained in any delimited episode or item is also not usefully measurable in units but roughly comparable in local circumstances
** Need not be encoded to be transmitted or saved.
* Utility or function counts against a creation, since copyright is intended to protect "artistic" creation.
* You have to be informed to begin with, you have to have many competences installed, before you can avail yourself of information. How are humans so much better at extracting information from the environment than any other species?
* We have many more affordances - a hardware store is a museum of affordances.
* Information is information, not matter or energy. No materialism that does not admit this can survive at the present day.

=== 7. Darwinian Spaces: An Interlude ===
* Darwin talked of "the infinite complexity of the relations of all organic beings to each other and to their conditions of existence".
* Evolution by natural selection is change in a population due to:
** variation in the characteristics of members of the population,
** which causes different rates of reproduction, and
** which is heritable.
* Whenever all three factors are present, evolution by natural selection is the inevitable result, whether the population is organisms, viruses, computer programs, words, or some other variety of things that generate copies of themselves one way or another.
* Darwin discovered the fundamental algorithm of evolution by natural selection, an abstract structure that can be implemented in different materials or media.
* Darwin refutes essentialism, the ancient philosophical doctrine that claimed that for each type of thing, each natural kind, there is an essence, a set of necessary and sufficient properties for being that kind of thing. But in fact there is no principled way of drawing a line between related things.
* A Darwinian space is a 3D array to show 3 variables and see to what extent a process is pure Darwinism, quasi-Darwinian, proto-Darwinian, or not Darwinian at all.
* Evolutionary processes are themselves evolutionary products and as a result emerge gradually and transform gradually.
* Looking at this is "Darwinism about Darwinism".
* We could for example look at the relationship between:
** Fidelity of heredity. Evolution depends on high-fidelity copying but not perfect copying, since mutations (copying errors) are the ultimate source of all novelty.
** Dependence of realized fitness differences on intrinsic properties. The differences in fitness between members of a population may depend on "luck" or "talent" or any combination in between. When luck is dominant, you can have genetic drift, when some random feature gets boosted to fixation.
** Continuity (smoothness of fitness landscapes). Natural selection is a gradual process and depends on blindly taking "small steps". When the landscape is "rugged" (rapidly changing), evolution is next to impossible since small steps are uncorrelated with progress or even maintaining one's fitness.
* De-Darwinizing is when a lineage that evolved for generations under paradigmatic Darwinian conditions moves into a new environment where its future comes to be determined by a less Darwinian process.
* The developmental process that wires up your brain is a de-Darwinized version of the process that evolved the eukaryotes. There are many neurons in your brain at birth and only those that make the right connections are saved, but they just happen to be in the right place at the right time.
* The origin of life (from the abiotic world to bacteria) is a set of processes that went from pre-Darwinian to proto-Darwinian to Darwinian.
* You can look at cultural evolution using a Darwinian space with the axes:
** Growth vs reproduction - eg the Roman Catholic Church grwos but seldom spawns descendants these days, while the Hutterites are designed to send of daughter communities whenever a community gets big enough. Religions are large complex social entities. Words are more like viruses, simpler, unliving, and dependent on their hosts for reproduction.
** Cultural vs genetic - Trust is (mainly) a cultural phenomenon
** Internal complexity
* An inverted Darwinian space shows Darwinian at the base and intelligent design at the opposite extreme, with the following axes:
** Bottom-up vs top-down - Human culture started out profoundly Darwinian, with uncomprehending competences yielding various valuable structures in roughly the way termites build their castles, and then gradually de-Darwinized, becoming ever more comprehending, ever more efficient in its ways of searching design space. As human culture evolves, it fed on the fruits of its own evolution, increasing its design powers by utilizing information in ever more powerful ways.
** Comprehension
** Random vs directed search
* All the real cultural phenomena occupy the middle ground, involving imperfect comprehension, imperfect search, and much middling collaboration.
* We are the only species so far that has developed explosively cumulative culture. Culture has obviously been a good trick for us, but what barriers have stood in the way of other species developing it?

=== 8. Brains Made of Brains ===
* A bacterium can discriminate a few vital differences to make itself at home in its tiny Umwelt.
* Swift control is the key competence of mobile organisms, so nervous systems, with a headquarters, are obligatory. Brains are control centers for dealing swiftly and appropriately with the opportunities and risks - the affordances - of a mobile life.
* Brains are designed by natural selection to have, or reliably develop, equipment that can extract the semantic information needed for this control task.
* Other mammals, and birds, can afford to be [[altricial]] in contrast to [[precocial]]; they are designed to be fed and protected by parents through a prolonged infancy, picking up semantic information that doesn't have to come through their genes and doesn't have to be learned by unsheltered trial and error in the dangerous world.
* Brains develop competences, including the meta-competences needed to acquire and hone further consequences.
* Turing was the epitome of a top-down intelligent designer.
* Computer programming is top-halfway-down design; the grubby details of the "bottom" of the design is something you can ignore (unless the program you are writing is a compiler.
* Complex evolvable systems (basically all living, evolvable systems) depend on being organized "hierarchically": composed of parts that have some stability independently of the larger system of which they are parts, and that are themselves composed of similarly stable parts composed of parts. A structure - or a process - need be designed only once, and then used again and again, copied and copied not just between an organism and its offspring, but within an organism as it develops. As Dawkins has observed, a gene is like a toolbox subroutine in a computer.
* In the genome, there is a vertebra-making subroutine, a finger-making subroutine, and eyelid making subroutine, each of these are modular tasks.
* The developing organism sorta understand the commands of its genes the way a von Neumann machine sorta understands its machine language instructions - it sorta obeys them.
* Bottom-up R&D is Darwin's strange inversion, but brains are not exactly like digital computers:
** Brains are analog and computers are digital.
** Brains are parallel and computers are (mainly) serial. - The brain's architecture is massively parallel, with a vision system about a million channels wide, but many of the brain's most spectacular activities are (roughly) serial, in the so-called stream of consciousness, in which ideas, or concepts or thoughts float by not quite in single file, but through a von Neumann bottleneck of sorts.
** Brains are carbon based (protein etc) and computers are silicon.
** Brains are alive and computers are not?
* Deacon argues that, by divorcing information processing from thermodynamics, we restrict our theories to basically parasitical systems, artifacts that depend on a user for their energy, for their structural maintenance, for their interpretation, and for their raison d'être. It is important, he claims, that a brain be made of cells that are themselves autonomous little agents with agendas, chief of which is staying alive, which spawns further goals, such as finding work and finding allies. His insistence on making brains (or brain substitutes) out of living neurons might look at first like some sort of romanticism - protein chauvinism - but his reasons are practical and compelling.
* The hardware of existing digital computers depends critically on millions (or billions) of identical elements. Neurons, in contrast, are all different, and they get organized not through bureaucratic hierarchies, but by bottom-up coalition-formation, with lots of competition.
* What do neurons want? Do they have nano-intentionality, agency? They want the energy and raw materials they need to thrive. Neurons are, like yeast and fungi, highly competent agents in a life-or-death struggle, in the demanding environment between your ears, where the victories go to those cells that can network more effectively, contributing to more influential trends at the levels where large-scale human purposed and urges are discernible.
* A neuron is always hungry for work; it reaches out exploratory dendritic branches, seeking to network with its neighbors in ways that will be beneficial to it.
* Top-down intelligent designs depend on foresight, which evolution utterly lacks. Evolution's design are all in a way retrospective - this is what worked in the past.
* Variable selective environments, because of their unpredictability, favor the selection of incomplete designs, along with mechanisms to tune the design to suit the circumstances, exploitable plasticity or "learning".
* Brains are more like termite colonies than intelligently designed corporations or armies.
* An organism's Umwelt is populated by two R&D processes:
** evolution by natural selection and
** individual learning of one sort or another.
* An organism is floating in an ocean of differences, a scant few of which might make a difference to it. Born to a long lineage of successful copers, it comes pre-equipped with gear and biases for filtering out and refining the most valuable differences, separating the semantic information from the noise.
* Bayesian hierarchical predictive coding - a method of calculating probabilities based on ones prior expectation:
** Given that your expectations based on past experience (including the experience of your ancestors as passed down to you) are such and such (expressed as probabilites for each alternative), what effect on your future expectations should the following new data have? What adjustments in your probabilities would it be rational for you to make?
** It is a normative discipline, purportedly prescribing the right way to think about probabilities.
** Computer reading of handwriting involves a cascade of layers in which the higher layers make Bayesian predictions about what the next layer down in the system with "see" next. When the predictions proves false, they then generated error signals in response that lead to Bayesian revisions, which are then fed back down toward the input again and again, until the system settles on an identification.
** Practice makes perfect, and over time these systems get better and better at the job, the same way we do - only better.
* Hierarchical, Bayesian predictive coding is a method for generating affordances galore - we expect solid objects to have backs that will come into view as we walk around them, we expect doors to open stairs to afford climbing, and cups to hold liquid.
* The network doesn't sit passively, waiting to be informed, but constantly makes probabilistic guesses about what will come next and treating feedback about its errors as the chief source of new information to guide its next round of guesses.
* In visual pathways, for example, there are more downward than upward pathways, more outbound that incoming signals. The brain's strategy is continuously to create "forward models" or probabilistic anticipations, and use the incoming signals to prune them for accuracy.
* When the organism is in deeply familiar territory, the inbound corrections diminish to a trickle and the brain's guesses, unchallenged, give it a head start on what to do next.
* This is descended from "analysis by synthesis"
* In a Bayesian network, silence counts as confirmation. Whatever the higher levels guess counts as reality by default in the absence of disconfirmation.
* These are expectation-generating fabrics with a remarkable competence they don't need to understand. They don't need to express or represent the reasons they track; like evolution itself, they "blindly" separate the information wheat from the chaff and act on it. Reasons are not things in their ontologies, not salient items in their manifest images.
* And these systems come, via cultural evolution, a whole new process of R&D, less than 1m years old - that designs, disseminates, and installs thinking tools by the thousands in our brains (and only ours), turning them into minds - not "minds" or sorta minds, but proper minds.
* One kind of neuron, the von Economo, or spindle cell, is found only in animals with very large brains and complex social lives: humans and other great apes, elephants and cetaceans.
* Brains are computers:
** composed of billions of idiosyncratic neurons that evolved to fend for them selves,
** their functional architecture is more like a free market that a "politburo" hierarchy where all tasks are assigned from on high
** They are composed of Bayesian networdks that are highly competent expectation-generators that don't have to comprehend what they are doing.
** Our kind of comprehension is only made possible by the arrival quite recently of a new kind of evolutionary replicator - culturally transmitted information entities: [[memes]].

=== 9. The Role of Words in Cultural Evolution ===
* The evolution of the evolution of culture is from:
** Profoundly Darwinian processes - involving minimal comprehension, bottom-up generation of novel products by random search processes, to
** Processes of intelligent design - comprehending, top-down generation of novel products by directed search.
* Words are the best example of memes
* Other species have some rudiments of cultural evolution that are not transmitted genetically between the generation but rather are ways of behaving that depend on the offspring's perception of the elders' behavior - an "instinct to learn" things like nest building or singing.
* Many animal behaviors that were thought to be genetically transmitted "instincts" have proven to be "traditions" transmitted between parent and offspring.
* We are the only species so far to have richly cumulative culture and this is primarily due to language. We have had a sustained population growth unprecedented by any other vertebrate.
* Our genes haven't changed very much in the last 50k years, and the changes with have seen are driven by new selection pressures created by human cultural innovations, such as cooking, agriculture, transportation, religion, and science.
* The widespread adoption of a new way of behaving creates a one-way ratchet: once almost everybody is eating cooked food, the human digestion system evolves, genetically, to make it no longer practical - and then no longer possible - for humans to live on a raw diet.
* One of the facts of life, both genetic and cultural, is that options become obligatory. A clever new trick that gives is users a distinct advantage over their peers soon "spreads to fixation", at which point those who don't acquire it are doomed.
* Eccentricities of a few members of the population bezcome a species necessity, embodied in an instinct.
* There is no law obliging people to have a credit card or a cellphone, but it is increasingly inconvenient to not have them.
* Words are the lifeblood, the backbone, the DNA of cultural evolution.
* Languages evolve like species, and/but there is widespread anastomosis, whereby what had been distinct lineages join together, as words jump between languages.
* In bacteria and other unicellular organisms, genes are often traded or shared by a variety of processes independent of vertical gene descent (reproduction). Similarly, etymologies (descent lineages) for words are more secure than the descent of the languages in which they are found, because of horizontal word transfer between languages.
* Charles Sanders Peirce's type/token distinction:
** "Word" is a word, and there are three tokens of that word in this sentence.
** Tokens can also be silent events in your brain. These brain-tokens will not look like "word" or sound like "word (they're brain events and it's dark and quiet in there), but they will no doubt by physically similar to some of the events that normally occur in your brain when you see of hear "word".
** There are lots of intermediate cases of words - definite specific words - tokened in our minds without going into the distinction between spoken or written, heard or seen. And there also seems to be "wordless" thinking where we don't even go to the trouble of "finding" all the words, but just tokening their bare meanings.
** Internal tokens seem to resemble external tokens, but this is because they make use of the very same neural circuitry we use to detect the resemblances and differences between external tokens, not because this neural circuitry renders copies of what it identifies.
** Any process that makes a new token of a type from an existing token of a type counts as a replication, whether or not the tokens are physically identical or even very similar. Tokens of words are all physical things of one sort or another, but words are, one might say, made of information, like software, and are individuated by types, not tokens, in most instances.
* Words are structures in memory that are autonomous in the sense that they must be independently acquired (learned). They are items of information, and other informational structures include stories, poems, songs, slogans, catchphrases, myths, techniques, "best practices", schools of thought, creeds, superstitions, operating systems, web browsers, Java applets.
* Informational structures comes in various sizes from large novels to shorter poems and traffic signs.
* Words have, in addition to the visible or audible parts of their tokens, a host of informational parts (making them nouns and verbs, comparatives and plurals, etc).
* Words are autonomous in some regards; they can migrate from language to language and occur in many different roles, public and private.
* A word, like a virus, is a minimal kind of agent: it wants to get itself said. Every token it generates is one of its offspring. The set of tokens descended from an ancestor token form a type, which is thus like a species.
* Some of a word's offspring will be private utterances: its human host is talking to herself, maybe even obsessively rehearsing the word in her mind, over and over, a population explosion of tokens, building an ever more robust niche for itself in a brain. And it may well be that many more internal tokenings - offspring - are born outside our conscious attention altogether. At this very moment, words may be replicating competitively in your head as inconspicuously as microbes replicate in your gut.
* The problem with introspection is that it acquiesces in the illusion that there is an inner eye that sees and an inner ear that hears - and an inner mind that just thinks.
* How do words get themselves installed in infant brains? Children learn about seven words a day, on average, from birth to age six, by which time they have a vocabulary of about 15k words

=== 10. The Meme's-Eye Point of View ===
* What are memes made of? They are a kind of way of behaving (roughly) that can be copied, transmitted, remembered, taught, shunned, denounced, brandished, ridiculed, parodied, censored, hallowed.
* Memes are ways: ways of doing something, or making something, but not instincts (which are a different kind of ways of doing something or making something). The difference is that memes are transmitted perceptually, not genetically. They are semantic information, design worth stealing or copying, except when they are misinformation, which, like counterfeit money, is something that is transmitted or saved under the mistaken presumption that it is valuable, useful/
* Words are the best examples of memes.
* Repetition is a key ingredient in creating new affordances. Multiple copies of anything tend to enable your pattern-recognition machinery to make yet another copy, in the recognizer, and thus a meme can get spread.
* Words are high on reproduction versus growth, high on culture versus genetic, and low on complexity.
* Once words are secured as the dominant medium of cultural innovation and transmission, they do begin to transform the evolutionary process itself, giving rise to new varieties of R&D much closer to the traditional, mythical ideal of intelligent design
* Ideas, practices, methods, beliefs, traditions, rituals, terms. These are all informational things that spread among human beings.
* A meme is any culturally-based way.
* Three conceptions of memes:
** Competence without comprehension - Human comprehension - and approval - is neither necessary not sufficient for the fixation of a meme in a culture.
** The fitness of memes. Memes thus have their own reproductive fitness, just like viruses.
** Memes are informational things. They are “prescriptions” for ways of doing things that can be transmitted, stored, and mutated without being executed or expressed.
* Natural selection of memes can do the design work without any obligatory boost from human, divine, or group comprehension.
* Even the meanings of words can evolve by processes quite outside the ken of those using the words, thanks to differential replication. The fact that changes in cultural features can spread without notice is hare to account for. Memes provide an alternative vision of how culture-borne information gets installed in brains without being understood. The default presumption of folk psychology is that people, and even “higher” animals, will understand whatever is put before them.
* “ One could then say, with complete rigor, that it is the sea herself who fashions the boats, choosing those which function, and destroying the others.”
* No comprehension is required even if it probably accelerates R1D processes more often than it retards them.
* The meme perspective covers the whole spectrum of mutualist, commensal, and parasitical symbionts.
* Only a tiny minority of the trillions of viruses that inhabit each of us right now are toxic in any way. Do we need some viruses in order to thrive? We certainly need lots of our memes.
* Many memes, maybe most memes, are mutualists, fitness-enhancing prosthetic enhancements of our existing adaptations (such as our perceptual systems, our memories, our locomotive and manipulative abilities).
* The prospective of parasitical memes exploiting that infrastructure is more or less guaranteed.
* What does fitness means in the context of evolutionary biology? Not health or happiness or intelligence or comfort or security, but procreative prowess.
* We are the only species that has managed to occupy a perspective that displaces genetic fitness as the highest purpose, the summum bonum of life. We are the only species that has discovered other things to die for (and to kill for): freedom, democracy, truth, communism, Roman Catholicism, Islam, and many other meme complexes (memes made of memes
* We are the persuadable species, not just learners, not just trainable, but also capable of being moved by reasons represented to us, not free-floating. We often have reasons for what we do, in this sense: we have articulated them to ourselves and have endorsed them after due consideration. The individual human being’s capacity to reason, to express and evaluate logical arguments, arises out of the social practice of persuasion. Our skills were honed for taking sides, persuading others in debate, not necessarily getting things right.

=== 11. What's Wrong with Memes? Objections and Replies ===
* Palpable, foldable dollar bills that are physical objects are ontological crutches of sorts.
* Memes exist because words are memes, and words exist, and so do other ways of doing things that are transmitted nongenetically.
* Nobody invented tonal music, but many musicians and music theorists contributed to codifying it and choosing the syllables to sing for each tone and perfecting a system of musical notation; a fine mixture of Darwinian cultural evolution and intelligent design over hundreds of years beginning in the eleventh century. Tonal music is a good example of a digitized alphabet that allows correction to the norm (You’re singing that note a bit sharp. Fix it!) Many musical innovations involve bending, sliding, deliberately flatting the notes (for instance in the blues), but standing behind these deviations are the canonical tones.
* Melody-world, an important part of our manifest image.
* A purely semantic-level replication.
* Memes are informational structures that are normally valuable - they are worth copying - and copyright laws have been devised and refined to protect that value. Not only translations, faithful or not, but also abridgements, cinematic treatments, plays and operas based on novels, and even video games can count as meme replications.
* What is particularly important in this exploration of memes is that some of these higher levels really do depend on comprehension, not just copying competence, even though they are based on, and rely on, systems of copying competence that do not require comprehension. In fact, from this vantage point we can see that the high-fidelity copying of DNA, our chief model for replication, stands out as an extreme case of mindlessness in replication.
* At higher levels, with more sophisticated, more competent “readers”, you can create systems that can tolerate more physical variation. Spoken words are the chief example here, but there are others. Scrambled words are easily unscrambled. Sentences can be read even if the vowels are removed. Turing saw the importance of basing his great invention on as mindless a recognition system as he could imagine - binary choices between 0,1.
* A thinko is like a typo, but at a higher, semantic level - misthinking, not miswriting. A thinko is a clear mistake in any endeavor where the assumed goals of the enterprise require certain identifiable “best practices”.
* Routines are themselves memes, hones by differential replication over the generations and composable into larger practices that can be “read” and “written” by experts. Making arrows and axes, tending fires, cooking, sewing, weaving, making pots and doors and wheels and boats, and setting out fishnets are ways that can be corrected over many generations by the combined action of simple physical requirements and local traditions.
* A reliable way of enhancing fidelity of transmission via unreliable, low-fidelity individual memories.
* Unison chanting is ubiquitous in traditional religions and other ceremonies, and it similarly serves to repair the memories of the changers, none of whom could provide a faithful copy of last year’s rendition unaccompanied.
* It’s tempting to see a gradual transition from:
** “infectious” rhythmic entrainment among tribespeople repeating their favorite moves and imitating each other.
** More self-conscious rituals (with rehearsal required and deliberate teaching and correcting) - the domestication of dance with careful control of reproduction.
** Professional choreographers - memetic engineers, intelligently designing their art objects.
* The original ways of dancing were memes that nobody “owned”, mindlessly evolving to exploit human idiosyncrasies of skeleton, gait, perception, and emotional arousal, habits that spread because they could spread, like the common cold.
* Infectious bad habits can be hard to eradicate, but if they can morph into useful habits, their reproductive prospects are enhanced. Once recognize, at first dimly (Darwin’s unconscious selection) and then consciously (Darwin’s methodical selection), their reproduction would be more or less ensured by their hosts, so the memes could relax, become less exciting, less irresistible, less captivating, less vivid, and unforgettable because they had become so useful. (The brains of domesticated animals are always smaller than the brains of their nearest wild kin; use it or lose it, and domesticated animals have a relatively unchallenging life, being protected from predators and starvation, and provided with mates at procreation time.) The corollary of this, of couse, is that for something boring to spread, it has to be deemed by its hosts to be particularly useful, or particularly valuable, and hence worth breeding: inculcating via extensive training.
* In general, any artifact found in abundance and showing signs of use is a good thing; following this rule, you can often tell the good one from the not so good ones without knowing exactly why the good ones are good. Copy the good ones, of couse. Darwin’s brilliant idea of unconscious selection as the gradualist segue into domestication gets put to important use in cultural evolution as well. Our ancestors “automatically” ignored the runts of the litter, and the lemons of the fleet, and the result in each case was the gradual improvement (relative to human tastes and needs) of the offspring.
* As with genes, mutations are transmission errors, but on occasion such an error is a serendipitous improvement.
* A lot of evolutionary R&D went into improving the replication machinery of DNA during the first billion or so years of life. The invention of writing has similarly boosted the fidelity of linguistic transmission, and it was the product. of many minds in many places over several millennia. Few if any of the “inventors” of writing had - or needed to have - a clear vision of the “specs” of the machine they were inventing, the “problem” they were “solving” so elegantly.
* “The written medium allows more complexity because the words on a page don’t die on the air like speech, but can be rescanned until you figure out what the writer intended.”
* The memes of the near future may thrive without direct human intervention, still synanthropic, like barn swallow and chimney swifts, but dependent on the amenities of the technological niche constructed in the 20th C by humans.
* Genetic evolution (“instincts”) can’t operate fast enough to do the job, leaving a yawning gap to be filled by memetics, and no positive ideas of anything else coming from traditional approaches to culture that could do the job.
* Memetics can also help depsychologize the spread on innovations (good and bad). Cultural anthropology takes people to be, in the first place, perceivers, believers, rememberers, intenders, knowers, understanders, noticers - cultural innovations are noticed and then (often) adopted. Here is a vision of people as rational agents, intentional systems whose behavior can be predicted. Cultural goods deemed valuable are preserved, maintained, and either bequeathed to the next generation or sold to the highest bidder. But much cultural innovations happens by what might be called subliminal adjustments over long stretches of time, without needing to be noticed or consciously approved at all. These accumulated shifts can often be recognized in retrospect, as when an expatriate community is joined by a new person from the old country whose way of speaking is both strangely familiar and strangely unfamiliar: Aha! I remember we used to talk like that too!
* Not just pronunciation and word meaning can subliminally shift. In principle, attitudes, moral values, the most emblematic idiosyncrasies of a culture can soften, harden, erode, or become brittle at a pace too slow to perceive. Cultural evolution is lightning fast, compared to genetic evolution, but it can also be much too gradual for casual observation to discern.
* Then there are pathological cultural variants, maladaptive cultural innovations, which no current theory can account for.
* Darwinian evolutionary processes are amplifiers of noise. Evolutionary theory, not being able to predict the once-in-a billion events that in due course get amplified into new species, new genes, new adaptations, can’t predict the future except very conditionally.
* The meme’s eye view fills the large and awkward gap between genetically transmitted instincts and comprehended inventions, between competent animals and intelligent designers, and it fills it with the only kind of theoretical framework that can nomiraculously account for the accumulation of good design: differential replication of descendants.
* Genes can’t explain adaptations. That’s true, and why we need molecular biology, physiology, etc. Similarly, we need psychology, anthropology, economics, political science, history, philosophy, and literary theory to explian how and why cultural features (good and bad) work the way they do.
* Nobody is born a pries or a plumber or a prostitute, and how they got that way is not going to be explained by their genes alone or just by the memes that infest them. My overarching claim in this book is that the evolutionary perspective in general and the memetic perspective with regard to culture transform many of the apparently eternal puzzles of life, that is, meaning and consciousness, in ways inaccessible to those who never look beyond the manifest image that they grew up with and the disciplines they are trained in.
* There is no way for an acquired trait to adjust an organism’s genes so that the trait gets passed along to the next generation genetically. Cultural transmission permits any traits that are acquired by the parent to be inculcated in the young (by setting an example, by training, by admonition).
* In memetic evolution, it is the fitness of the memes themselves that is at stake, not the fitness of their hosts
* Memes don’t have genes.
* We can consider words, and memes more generally, to be the result of variable, temporally extended processes of reproduction, and imaginable variation on our normal mode of secual reproduction.
* Some of the marvels of culture can be attributed to the genius of their creators, but much less than is commonly imagined, and all rests on uncomprehending hosts of memes competing with each other for rehearsal time in brains.
* Perhaps the chief benefit of the meme’s-eye point of view is that it suggest questions about cultural phenomena that we might not otherwise think of asking, such as: Is x the result of intelligent design? Is x a good worth preserving and bequeathing or a bit or parasitic junk? Are there alternatives (alleles) to x that have been encountered and vanquished?
* Only when those accounts attribute comprehension to people (or mysterious social forces) for which there is no evidence, does our perspective provide a level playing field where all degrees and kinds of human comprehension can be located.
* “Descent with modification”

=== 12. The Origins of Language ===
* The origin of language is like the topic of the origin of life itself. Both are probably unique events on this planet. It is seen as "the hardest problem in science".
* What might the ancestors of today's well-designed languages have been? They were probably inefficient, hard-to-learn behavioral patterns that seldom "worked". What conditions had to be in place to make those early versions worth investing in? They may not even have "paid for" the expense of using them. They may have been parasitic habits that were infectious and hard to share. We should be on the lookout for a circuitous route, with gambits galore. The early days of language might have been more of an imposition than a gift.
* Functions that languages eventually serve:
** Communicative utility - command, request, inform, inquire, instruct, insult, inspire, intimidate, placate, seduce, amuse, entertain.
** Productivity - generate a vast number of different meanings (sentences, utterances) composed from a finite stoci of lexical items. There is no end to the number of grammatical sentences in English.
** Digitality - correct to the norms, rinsing much of the noise out of the signal
** Displaced Reference - refer to things not present in the environment of the communicators
** Ease of Acquisition - the remarkable swiftness with which spoken or signed language is picked up by children.
* No other species has a faculty remotely like human language in its power. We have an instinct to cooperate with our extended family, enhanced dispositions to cooperate. Words may be the best memes, but they weren't the first memes. Did group cooperation evolve before language? What benefit got our ancestors' children so interested in the vocalizations of their group and so eager to imitate them?
* Can we imagine young hominins acquiring the self-control and foresight to tend a fire effectively without verbal instruction? Could the cave paintings at Lascaux (20-30k ya) have been painted by H. sapiens artists without language.
* A bias that is apt to be more valuable than "copy anything that moves" or "copy the first adult you see" is "copy the majority" (conformist bias) "copy the successful" or "copy the prestigious".
* When does a habit of (basically clueless) copying do better than engaging in your own trial and error learning?
* Viruses can't reproduce on their own. They depend on commandeering the reliable copy machinery in the nucleus of living cells, and that copy machinery was the product of a billion years of R1D. Memes, helpful or not, must above all get themselves copied - dispositions to attend to others, and to copy some of the ways perceived, it the only ground in which memes could take root and bloom.
* Once a rudimentary copy system is in place, it can be hijacked by selfish interlopers. Perhaps we are just apes with brains being manipulated by memes in much the way we are manipulated by the cold virus. Instead of looking only at the prerequisite competences our ancestors needed, we should also consider unusual vulnerabilities that might make our ancestors the ideal hosts for infectious but nonvirulent habits (memes) that allowed us to live and stay mobile long enough for them to replicate through our populations. Perhaps we should think of astronauts going to the moon as the memes way of getting into the next generation of science nerds.
* Adaptations (fitness enhancers) can be either genetically or culturally transmitted. The genetic information highway has been optimized over billions of years with DNA copying machines, editing machines, and systems for dealing with genomic parasites. The cultural highway, over a much shorter time period, has also evolved a host of design features to facilitate reliable transmission of information. A coevolutionary process in which the "research" is mainly done by the memes and the later "development" is mainly done by the genes. Innovations in memes could provide the early "proof of concept' that would underwrite, in effect, the more expensive and time-consuming genetic adjustments in brain hardware that would improve the working conditions for both memes and their hosts.
* Software innovations leading the way and hardware redesigns following, innovations that were first designed as software systems, as simulations of new computers running on existing hardware computers. Today’s smartphones have, in addition to layers and layers of software running on software running on software, special-purpose graphics and speech-synthesis and recognition hardware in their microprocessors, the descendants of software systems that explored the Design Space first.
* Cellphones have special-purpose hardware for speech processing but not for speaking English of Chinese. In the same way, an infant brain is language neutral: versatility widens the “market” for the design.
* The Baldwin Effect reduces genetic variance and versatility by driving a behavior (or developmental option) into a “best practices” straitjacket controlled genetically, turning options into obligate behaviors.
* We can think of copiers as information scroungers and learners as information producers. Mindlessly copy the majority turns out to be a remarkably effective strategy. The individuals with competence (or behavioral comprehension) soon lose their advantage to the copiers.
* Cultural transmission won’t evolve except in a Goldilocks environment that is neither too hot - chaotic - nor too cold - unchanging - for long enough to provide evolution a chance to create some new habits and fix them in a population.
* Culture has been a spectacularly successful Good Trick for H sapiens.
* For bipedality, did rudimentary tool making create a selection pressure for the ability to carry raw materials or finished tools for long distances, or did upright walking, evolved for other reasons, open up the Design Space for effective tool making?
* Another proposed threshold is social intelligence. The competence to interpret others as intentional systems whose actions can be anticipated by observing what these others observe and figuring out what they want (food, escape, to predate you, a mating opportunity, to be left alone)
* Language may not be the foundation, but I wouldn’t call it the capstone; I would call it the launching pad of human cognition and thinking.
* Niche construction: organisms don’t just respond to the selective environment they are born into. Their activities can also revise the features of that environment quite swiftly, creating whole new selection pressures and relieving others. Our species has engaged heavily in niche construction. Steven Pinker calls our world the “cognitive niche”, stressing that it is a product of human comprehension. Others disagree, proposing that it would better be called the “cultural niche”, a platform of competences on which comprehension can grow. The R&D that has constructed the niche we inhabit today is a changing blend of both Darwinian, bottom-up processes and top-down intelligent design. Our niche is certainly unlike that of any other species. It includes hardly any prey or predators (unless you’re a fisherman or a surfer in shark-filled waters), where habitants are composed of almost nothing but artifacts and domesticated plants and animals, where social role, wealth, reputation, expertise, and style (of clothing, speaking, singing, dancing, playing) have largely supplanted stronger muscles, faster running, and keener eyesight as variable advantages that bestow genetic fitness.
* Some of these meme transmissions required joint attention, some required (proto-)linguistic direction, and some required fully linguistic instructions, including mnemonic mantras and other devices, no doubt.
* How can any parent animal convey some of its hard-won experience to its young without language. The capacity of language to direct attention to non- present things and circumstances is a huge enhancement.
* There is a gradient between “instinct” and “learned behavior”, not a dichotomy.
* Possible steps towards language:
** A proto-language of short utterances, lacking productivity or any distinction between imperatives and declaratives. These signals would be appropriate and recognized reactions to important affordances, and hence affordances themselves.
** Perhaps a gesture language rather like the signing languages of the Deaf came first, with vocalizations used for attention-grabbing and emphasis. Speaking without gesturing is a difficult feat for many people, and it might be that gesturing and vocalizing have traded places, with gestures now playing the embellishing role that was originally played by vocalizations. The vestigial hand movements so many of us find all but irresistible may in effect be fossil traces of the original languages.
** Perhaps there was an auditory “peacock’s tail” arms race, with male hominins vying to display their talent for musical vocalization, eventually including improvisations, like the competitive displays of nightingales and other songbirds.
* Language has two distinct compositional systems, “phonotactics” (governing which phonemes can follow which, independent of meaning) and “morphosyntax” (governing word order and the use of prefixes and suffices to build meanings out of meanings). Why two compositional levels, one semantic and one not? The productivity of languages is “motivated by” the usefulness of being able to communicate many things about the world.
* Depending on age and personality, people end up talking like the people around them, often without conscious effort. The evolution of vowel systems is thus a case of self-organization”. A system evolves not through any deliberate planning, but through the accumulation over time of a myriad of little adjustments by individuals responding to immediate pressures.
* It was in the interest of audible memes, meaningful or not, to distinguish themselves from the competition but also to exploit whatever habits of tongue prevailed locally, whereas it was in the interests of host/speaker/hearers to minimize the load on memory and articulation by keeping the repertoire of distinct sound-types fairly compact and efficient. No “conscious effort” is required because the immediate pressures are the selective pressures of differential replication.
* Over repetitions, the more readily perceived/remembered patterns survive while the others go extinct. And all are memes designed by differential replication to propagate in spite of providing not benefit beyond a reward for copying.
* A bounty of productively generated sounds looking for work is a more productive workshop of "invention" than a passel of distinctions with no sounds yet to express them. It takes a particular sort of intelligent designer to coin an apt and useful neologism. Sounds already in circulation could have been more or less unconsciously adopted to serve on particular occasions, the coinciding in experience of a familiar sound and a salient thing (two affordances) being wedded on the spot to form a new word, whose meaning was obvious in context.
* This populates the lexicon with phonology and semantics, but where does grammar come in? Isolated, conventionally fixed articulations are, like alarm calls, limited in semantic variety: hello, ouch, yikes, aaah, scram.
* The noun-verb distinction - Every language needs a topic/comment distinction (what you are talking about and what you are saying about it.
* Content words are almost never descended from function words.
* There is a robust negative correlation between the morphological complexity of a language and the size of the population that speaks it.
* Contact between adults speaking different languages tends to produce varieties of language in which morphological complexity is stripped out.
* The first words were, no doubt, assigned to the “things we had concepts for”, those things for which we were ready to discriminate these affordances, attend to them, track them, and then deal appropriately with them under normal circumstances.
* There are three kinds of entities: linguistic entities, mental entities, and worldly objects and relations. Two affordances unite to form something new, a concept in the specifically human sense of a word with an understood meaning.
* I can wonder what these things are called and what this sound means.
* Out of a rather chaotic jumble of opportunities, regularities can emerge, with only intermittent attention and hardly any intention. When things become familiar enough, they can be appropriated: my block, my dolly, my food, and my words - not at first consciously thought of as mine but just handled as possessions. With discrimination and recognition comes the prospect of reflection.
* The higher-order pattern of sameness and difference, which then become two additional things in the manifest image of the child. These iterated manipulations provide an engine of recombination from which the densely populated manifest image of a maturing human child can be constructed.
* Brains are well designed for picking up affordances of all kinds and refining the skills for responding to them appropriately. Once a brain starts being populated with pronounceable memes, they present as opportunities for mastery, and the pattern-finding powers of the brain get to work finding relations between them and the other available affordances.
* Children acquire the meaning of most of these words gradually via unconscious, involuntary statistical analysis of the multifarious stimuli they encounter.
* Can grammatical and morphological rules be acquired by bottom-up processes, competent and uncomprehending? Yes, since nobody learns the grammar of their first language “top-down”.
* At one extreme the wok is done by a pattern-finding competence that is completely general and has nothing specific in it about language, and at the other extreme is an almost-complete innate system (universal grammar) that just needs to have its “parameters” set for one language or another by experience.
* The mainly learning end of the spectrum suggests a ubiquitous gradualness, as much a feature of grammatical categories as of species and subspecies.
* Consider idioms like:
** One fell swoop and in cahoots that are quite impervious to internal analysis
** That doesn’t cut any ice and kick the bucket, whose meanings cannot be derived by analyzing their parts
** Pass muster and close quarters, which are analyzable if you have the context
** Prominent role, mixed message, and beyond repair, which are conventionalized but predictable
** Where the truth lies and bottom-up processes, which can be understood by anyone who knows the meaning of the components
* Grammaticalization takes frequently replicated combinations and gradually hardens them into units that can then replicate on their own as combinatorial units
* When, if ever, do any two speakers speak exactly the same language? We could say that each speaker has an idiolect, a dialect with a single native user
* If we reposition Chomsky’s Merge, or something like it, as an early candidate for a transitional innovation on the way to modern languages, then we can reconcile early and late Chomsky by saying the “intricate structure of specific rules and guiding principles” are not so much explicit rules as deeply embedded patterns in ways of speaking that consist of a series of improvements wrought by evolution, both cultural and genetic, in response to the success of protolanguages

== Part III: Turning Our Minds Inside Out ==
=== 13. Consciousness as an Evolved User-Illusion ===
=== 14. The Age of Post-Intelligent Design ===
[[Category:Consciousness]]
[[Category:Books]]

Books

2025-04-12T16:14:40Z

Rob:

== Books to Buy ==

* Language, Thought, and other Biological Categories
* The Flat Mind
* On the Calculation of Volume - Solvej Balle
* Open Socrates - Agnes Callard
* Why Machines Learn: The Elegant Maths Behind Modern AI (out in paperback Jan 30 2025)
* A History of the Muslim World: From Its Origins to the Dawn of Modernity (awaiting paperback)
* How Life Works: A User’s Guide to the New Biology
* Stranger Than Fiction: Lives of the Twentieth-Century Novel
* Grey Matters: A Biography of Brain Surgery - not yet in paperback
* The New Roman Empire: A History of Byzantium
* Magnetic Mountain: Stalinism as Civilization
* Consolations - David Whyte

== Books to Read ==

* Why we remember
* Reading to Learn - William Zinger
* Breakfast of Champions - Kurt Vonnegut
* A Little History of Philosophy - Nigel Warburton

== Books Read ==

=== 2025 ===

* [[From Bacteria to Bach and Back]] - Daniel Dennett (re-read)
* [[Why We Remember: Revealing the Hidden Power of Memory]] - Dr Charan Ranganath
* [[The Village of Eight Graves]] - Seishi Yokomizo
* [[Science: A History]] - Richard Crockett
* [[Vienna: How the City of Ideas Created the Modern World]] - John Gribbin
* [[The Inugami Curse]] - Seishi Yokomizo
* [[The Rise and Reign of the Mammals]]
* [[Four Ways of Thinking]] - David Sumpter
* [[I've Been Thinking]] - Daniel Dennett
* [[Serendipities: Language and Lunacy]] - Umberto Eco
* [[I Am Dynamite: A Life of Friedrich Nietzsche]] - Sue Prideaux
* [[A Brief History of Intelligence]] - Max S. Bennett
* [[Foucault’s Pendulum]] - Umberto Eco (re-read)
* [[Kant and the Platypus]] - Umberto Eco
* [[Le cerveau m’a beaucoup déçu. L’esprit, non]] - Antoine Sénanque

=== 2024 ===

* The Plot - Will Eisner
* The Prague Cemetery - Umberto Eco
* The Nonjin Murders - Seishi Yokomizo
* When We Cease to Understand the World - Labatut
* Zen and the Art of Motorcycle Maintenance - Robert Pirsig (reread)
* The Way We Think: Conceptual Blending and the Mind’s Hidden Complexities - Fauconnier and Turner
* The Singularity is Nearer - Ray Kurzweil
* Physics and Philosophy - Werner Heisenberg
* Le Ton Beau de…
* The Origins of Creativity - Edward O Wilson
* Psychonauts -
* The MANIAC - Benjamin Labatut
* In Search of Memory - Eric R. Kandel
* Dreaming: A Very Short Introduction - Hobson
* Les Effinger - Gabriele Target
* Triad - Tom Keve
* Nietzsche - Stefan Zweig
* The Weirdest People in the World - Joseph Henrich
* How Language Works - David Crystal
* The Invention of Nature - Andrea Wolf
* The Song of the Cell - Siddhartha Mukherjee
* [[Gödel, Escher, Bach]] - Douglas Hofstadter
* [[From Bacteria to Bach and Back]] - Daniel Dennett

[[Category:Books]]

Why We Remember: Revealing the Hidden Power of Memory

2025-04-12T15:57:41Z

Rob: Created page with "== Where is My Mind? == * By one estimate, the average American is exposed to 34GB (or 11.8hr) of information a day * Hermann Ebbinghaus “On Memory: A contribution to Experimental Psychology (1885) - tried to memorize trigrams, established the idea of a forgetting curve over time. * In essence, neurons function like a democracy with alliances or “cell assemblies”. * Somewhere is the brain’s speech centers a large coalition of neurons cases votes for “bath”,..."

Films

2025-04-12T15:21:57Z

Rob: /* Films Watched */

== Films to Watch ==
* Witness
* In the line of fire
* Lincoln
* Empire of the Sun
* Early Steve Martin
* A Complete Unknown
* Mickey 17
* la La Land -
* Eternal Sunshine - wtb
* The Phoenician Scheme - new Wes Anderson comedy espionage thriller
* Thelma - Grandma fights con artists
* Hundreds of Beavers - crazy live action cartoon
* Kinds of Kindness
* 2001
* The Elephant Man
* The Fabulous Baker Boys
* Network

== Films Watched ==
=== 2025 ===

* Total Recall 1990 (rewatch)
* In the Line of Fire
* Flow
* Juror No. 2
* The Savage Robot
* Eternal Sunshine of the Spotless Mind
* Dead Poet's Society
* Notting Hill (rewatch)
* My Neighbor Totoro (rewatch)
* Kiki’s Delivery Service (rewatch)
* Dr Strangelove
* Dune 2
* Austin Powers: The Spy who Shagged Me

=== 2024 and Earlier ===
* The Big Lebowski
* The Holiday
* Love Actually
* Bill and Ted's Excellent Adventure
* The Mask
[[Category:Films]]

The Inugami Curse

2025-04-12T15:20:43Z

Rob: Created page with "The first book in the series was interesting as a locked room mystery, but ultimately disappointing. This one, with masks and mistaken identities is fine enough, but the main trick was easy to see through (even if the ultimate use of it was not). The influence of John Dickson Carr is pretty heavy here."

The first book in the series was interesting as a locked room mystery, but ultimately disappointing. This one, with masks and mistaken identities is fine enough, but the main trick was easy to see through (even if the ultimate use of it was not). The influence of John Dickson Carr is pretty heavy here.

The Village of Eight Graves

2025-04-12T15:18:29Z

Rob: Created page with "Hmm. I think I’m out. There is some decent plotting here, but the murderer seemed obvious to me from quite early on and the motive (and means) are not very credible. The limestone caves are an interesting decor, but not well exploited and the constant gothic drama gets tedious."

Books

2025-04-12T15:16:04Z

Rob: /* 2025 */

== Books to Buy ==

* Language, Thought, and other Biological Categories
* The Flat Mind
* On the Calculation of Volume - Solvej Balle
* Open Socrates - Agnes Callard
* Why Machines Learn: The Elegant Maths Behind Modern AI (out in paperback Jan 30 2025)
* A History of the Muslim World: From Its Origins to the Dawn of Modernity (awaiting paperback)
* How Life Works: A User’s Guide to the New Biology
* Stranger Than Fiction: Lives of the Twentieth-Century Novel
* Grey Matters: A Biography of Brain Surgery - not yet in paperback
* The New Roman Empire: A History of Byzantium
* Magnetic Mountain: Stalinism as Civilization
* Consolations - David Whyte

== Books to Read ==

* Why we remember
* Reading to Learn - William Zinger
* Breakfast of Champions - Kurt Vonnegut
* A Little History of Philosophy - Nigel Warburton

== Books Read ==

=== 2025 ===

* [[Why We Remember: Revealing the Hidden Power of Memory]] - Dr Charan Ranganath
* [[The Village of Eight Graves]] - Seishi Yokomizo
* [[Science: A History]] - Richard Crockett
* [[Vienna: How the City of Ideas Created the Modern World]] - John Gribbin
* [[The Inugami Curse]] - Seishi Yokomizo
* [[The Rise and Reign of the Mammals]]
* [[Four Ways of Thinking]] - David Sumpter
* [[I've Been Thinking]] - Daniel Dennett
* [[Serendipities: Language and Lunacy]] - Umberto Eco
* [[I Am Dynamite: A Life of Friedrich Nietzsche]] - Sue Prideaux
* [[A Brief History of Intelligence]] - Max S. Bennett
* [[Foucault’s Pendulum]] - Umberto Eco (re-read)
* [[Kant and the Platypus]] - Umberto Eco
* [[Le cerveau m’a beaucoup déçu. L’esprit, non]] - Antoine Sénanque

=== 2024 ===

* The Plot - Will Eisner
* The Prague Cemetery - Umberto Eco
* The Nonjin Murders - Seishi Yokomizo
* When We Cease to Understand the World - Labatut
* Zen and the Art of Motorcycle Maintenance - Robert Pirsig (reread)
* The Way We Think: Conceptual Blending and the Mind’s Hidden Complexities - Fauconnier and Turner
* The Singularity is Nearer - Ray Kurzweil
* Physics and Philosophy - Werner Heisenberg
* Le Ton Beau de…
* The Origins of Creativity - Edward O Wilson
* Psychonauts -
* The MANIAC - Benjamin Labatut
* In Search of Memory - Eric R. Kandel
* Dreaming: A Very Short Introduction - Hobson
* Les Effinger - Gabriele Target
* Triad - Tom Keve
* Nietzsche - Stefan Zweig
* The Weirdest People in the World - Joseph Henrich
* How Language Works - David Crystal
* The Invention of Nature - Andrea Wolf
* The Song of the Cell - Siddhartha Mukherjee
* [[Gödel, Escher, Bach]] - Douglas Hofstadter
* [[From Bacteria to Bach and Back]] - Daniel Dennett

[[Category:Books]]

From Bacteria to Bach and Back

2025-04-10T09:12:08Z

Rob: /* 12. The Origins of Language */

From Bacteria to Bach and Back

2025-04-07T17:31:35Z

Rob: /* 11. What's Wrong with Memes? Objections and Replies */

From Bacteria to Bach and Back

2025-04-06T14:39:41Z

Rob:

From Bacteria to Bach and Back

2025-04-06T14:38:29Z

Rob: /* 10. The Meme's-Eye Point of View */

From Bacteria to Bach and Back

2025-04-06T14:02:27Z

Rob: /* 10. The Meme's-Eye Point of View */

Science: A History

2025-04-06T10:47:02Z

Rob: /* Outer Space */

== Origins ==

* One potential date for the beginning of the revival of Western Europe is 1453:
** Publication of "On the Structure of the Human Body" by Andreas Vesalius and of "On the Revolutions of the Celestial Bodies" by Copernicus", mark the start of the scientific revolution that would transform first Europe and then the world.
** The Turks captured Constantinople marking the end of the old Roman Empire, causing many Greek-speaking scholars fled westwards to Italy with their documents, and there the Italian humanists took up these documents and the teaching found therein to -establish civilization along the lines that head existed before the Dark Ages.
** Perhaps equally important was the depopulation of Europe by the Black Death in the 14th C, which led the survivors to question the whole basis of society, made labor expensive and encouraged the invention of technological devices to replace manpower.
** Also, Gutenberg's development of moveable type in the mid 15th C had an obvious impact on what was to become science, and discoveries brought back to Europe by another technological development, sailing ships capable of crossing the oceans, transformed society.
* The scientific revolution did not happen in isolation, but eventually became the driving force of Western civilization over the next 450 years.
* The development of technology is more important than human genius, and it is no surprise that the start of the scientific revolution "coincides" with the development of the telescope and the microscope.
* Western science got started because the Renaissance happened. And once it got started by giving a boost to technology it ensured that it would keep on rolling, with new scientific ideas leading to improved technology, and improved technology providing the scientists with the means to test new ideas to greater and greater accuracy. Technology came first, because it is possible to make machines by trial and error without fully understanding the principles on which they operate. But once science and technology got together, progress really took off.

== Renaissance Men ==
* Nicolaus Copernicus (1473-1543) - "On the Revolution of the Celestial Spheres" (1543)
* Andreas Vesalius (1514-1564) - "On the Structure of the Human Body" (1543)
* William Harvey - discovery of the circulation of the blood.
* Gabriele Fallopio - discover of the fallopian tubes

== The Last Mystics ==
* Tycho Brahe (1546-1601) - De Nova Stella (1573)
** Sees a comet in 1577. First astronomer to imagine the planets hanging unsupported in space
* Johannes Kepler (1571-1630) - The Mystery of the Universe (1597)
** Suggested that planets were kept moving in their orbits by a force he called "the vigour" reaching out from the Sun and pushing them along.
** "My aim is to show that the machine of the universe is not similar to a divine animated being, but similar to a clock."
** First and second laws about planetary orbits.
** "Astronomia Nova" (1609)
** "Harmony of the World" (1618) - Third law about planetary orbits
** Writes one of the first science-fiction stories, "Dream of the Moon
* John Napier (1550-1617) - Invented logarithms

== The First Scientists ==
* William Gilbert (1544-1603)
** Concerning Magnetism, Magnetic Bodies, and the Great Magnet Earth (1600)
** Discovered laws of attraction and repulsion, that the Earth acts like a magnet, names the north pole and south pole
** Nothing new was discovered about magnetism until the discovery of electromagnetism in the 1820s
** Galileo described Gilbert as the founder of the experimental method of science.
* Galileo Galilei (1564-1642)
** Always carried out experiments to test hypotheses, modifying or abandoning those hypotheses if the outcomes of the experiments did not match their predictions.
** Also investigated hydrostatics, magnetism
** Proved that a bullet fired from a gun describes a parabola
** Built a telescope better than any other in just 24hrs
** Discovered the four largest moons of Jupiter early in 1610, that the Milky Way is made up of many individual starts, and that the surface of the Moon is scarred by craters and has mountain ranges several km high in book The Starry Messenger (1610)
** He was willing to test his reasoning by clearly thought-out experiments, in public, and to stand by the results.
** Was one of the first to develop an effective compound microscope, involving two lenses each ground with a doubly convex shape.
** Dialogue on the Two Chief World Systems (1629)
** Discourses and Mathematical Demonstrations Concerning Two New Sciences (1638) - summed up his life’s work on mechanics, inertia, and pendulums and the strength of bodies, as well as spelling out the scientific method. The first modern scientific textbook, spelling out that the Universe is governed by laws which can be understood by the human mind and is driven by forces whose effects can be calculated using maths.
** Realized that moving objects have a natural tendency to keep on moving, unless they are affected by friction or some other outside force.

== Science Finds its Feet ==

* The symbols + and - were only introduced to maths in 1540 in Robert Recorde’s « The Grounde of Artes
* In another book, « Whetstone of Witte » (1557), he introduced the equals sign.
* The multiplication symbol was introduced in 1631, and the division symbol in 1659.
* The introduction of logarithms early in the 17th C enormously simplified and speeded up the laborious processes of calculations for astronomers and other scientists.
* Logarithms are a way to "undo" exponentiation. If $b^y = x$, then we say that the logarithm base $b$ of $x$ is $y$, written as $\log_b(x) = y$. In simpler terms, a logarithm answers the question: "To what power must I raise the base $b$ to get the number $x$?"

For example, since $10^2 = 100$, we know that $\log_{10}(100) = 2$. Here, 10 is the base, 100 is the number, and 2 is the logarithm (or the exponent).

Logarithms are incredibly useful for simplifying complex calculations, especially those involving very large or very small numbers. They turn multiplication into addition, division into subtraction, and exponentiation into multiplication. This made them invaluable before the age of calculators and continues to be important in various fields like science, engineering, and finance.
* Réné Descartes (1596-1650)
** A Discourse on the Method of Rightly Conducting Reason and seeking Truth in the Sciences (1637)
** Cartesian co-ordinates (x,y) allowed geometry to be analyzed using algebra
** Mediationnes de Prima Philogsophia (1641)
** Principia Philosophiae (1644)
* Blaise Pascal (1623-1662)
* Pierre Gassendi (1592-1655) - revived the concept of atomism, which dates back to Democritus in the 5th C BC
* Evangelista Torricelli (1608-1647) - invented the barometer and created a vacuum
* Christiaan Huygens (1629-1695) - from 1658 allows ordinary people to have access to accurate timepieces.
** Uses the Aether to explain how light is refracted
** Treatise on Light (1690)
* Royal Society is founded in London in 1645, In Paris, the Académie des Sciences in 1667
* Ole Romer (1644-1710) Calculated the speed of light as 225,000km/s, very close to the modern calculation of 299,792km/s
* Robert Boyle (1627-1691)
** « We assent to experience, even when its information seems contrary to reason. »
** The Spring of the Air (1660) - treats air pumpts and the problem of raising water by suction. Boyle’s la. Seen as a turning point for chemistry.
** Came close to discovering Oxygen - essential similarities between the processes of respiration and combustion.
** His most famous book, The Sceptical Chymist (1661)
** Origin of Forms and Qualities (1666)
* Marcelo Malpighi (1628-1694) - Circulation of the blood
* Giovanni Borelli (1608-1679)
** On the Movement of Animals (1680-1681) - treated the body as a system of levers acted on by the forces exerted by the muscles, and analysed geometrically how muscles in the human body acted in walking and running.
* Edward Tyson (1650-1708) - founding father of comparative anatomy
** Anatomy of a Porpess
** Orang-Outang - evidence that humans and chimps were built to the same body plan. The place of human beings as part of the animal kingdom is clearly established.

== The Newtonian Revolution ==
* Robert Hooke (1635-1703):
** Micrographia (1665) - the first subtantial book on microscopy by any major scientist. Marked the moment when microscopy came of age as a scientific discipline. Included the "cellular" structure of slices of cork - first use of the word cell
** He realized that the orbital motion results from the tendency of the Moon to move in a straight line, plus a single force pulling it toward the Earth.
* Isaac Newton (1643-1727):
** Calculus makes it possible to calculate accurately, from a known starting situation, things that vary as time passes, such as the position of a planet in its orbit. Provided the mathematical tools needed to study processes in which change occurs. Modern physical science simply would not exist without calculus.
** Newton wondered whether, if the influence of the Earth's gravity could extend to the top of the tree, it might extend all the way to the Moon. He then calculated the force required to hold the Moon in its orbit and the force required to make the apple fall from the tree could both be explained by the Earth's gravity if the force fell off as one over the square of the distance from the centre of the Earth.
** Principia Mathematica (1687) - He laid the foundations for the whole of physics, not only spelling out the implications of his inverse square law of gravity and the three laws of motion, which describe the behavior of everything in the Universe, but making it clear that the laws of physics are indeed universal laws that affect everything. The realization that the world works on essentially mechanical principles that can be understood by humand beings, and is not run in accordance with magic or whims of capricious gods.
** Opticks (1704)

== Expanding Horizons ==
* In the century after Newton, there was a huge expansion of the realm which science attempted to explain.
* Edmond Halley (1656-1741):
** Questioned the accepted date of the Creation, 4004 BC
** Studied variations in atmospheric pressure and winds
** Experimented with a diving bell to a depth of 18m
** 1698 Voyage of the Paramore for a year to the South Atlantic
** "A Synopsis of the Astronomy of Comets" (1705)
** Flamseed's star catalogue containing 3,000 star positions (1725)
** 1720 Appointed as Astronomer Royal
** Correctly predicted the return of Halley's comet after his death in 1758-9 and transits of Venus in 1761 and 1769. These latter were used to work out the distance to the Sun at 153m km, very close to the modern measurement of 149.6m km.
* John Ray (1627-1705) - the biological equivalent of Newton:
** Ornithology (1677)
** History of Fishes (1686)
** History of Plants (1686, 88, 1704) - covering 18,000 plants, classified plants in terms of their family relationships, morphology, distribution and habitats.
** Established the species as the basic unit of taxonomy
** History of Insects (1710)
** Made the study of botany and zoology a scientific pursuit, bring order and logic to the investigation of the natural world
** Invented a clear taxonomic system based on physiology, morphology, and anatomy, paving the way for the work of Linnaeus.
* Carl Linnaeus (1707-1778)
** Plants reproduced sexually and had male and female parts
** Could not understand anything that is not systematically ordered.
** Systema Naturae (1735) - Introduces the binomial system of classifying every species with a two-word name. Introduced the terms Mammalia, Primates, and Homo sapiens.
** Provided descriptions of 7700 species of plants and 4400 species of animals. Everything in the living world was arranged in a hierarchy of family relationships, from the broad classifications of their Kingdom and class down through the subdivisions Order and Genus to the Species itself. This systm preserves the last vestige of Latin in scientific work right up to the present day.
** Paved the way from which the relationships between species and the laws of evolution would begin to become clear in the 19th C.
** Was the first person to include man in a system of biological classification. I have yet to find any characteristics which enable man to be distinguished on scientific principles from an ape
** Nowadays, using DNA evidence, man would be classified as a chimpanzee.
* Anders Celsius (1701-1744)
* Nicolaus Steno (1638-1686)
* Comte de Buffon (1707-1788):
** Histoire Naturelle in 44 volumes between 1749-1804 - the first work to cover the whole of natural history
** Speculated that the Earth had formed out of material thrown out of the Sun as the result of the impact of a comet.
** Calculated that the Earth must be at least 75k years old
* Jean Fourier (1768-1830):
** Fourier Analysis - mathematical techniques for dealing with time-varying phenomena
** Developed sets of equations to describe heat flow
** Calculated the age of the Earth as 100m years
* Georges Couvier (1769-1832)
** Lectures in Comparative Anatomy (1800)
** Probably the most influential biologist in the world in the 1830s
** Compared the bodies of meat-eating and plant-eating animals
** Arranged all animals into four major groups (vertebrates, molluscs, articulates, and radiates), which each had its own kind of anatomy.
** Almost single-handedly invented the science of paleontology - could say which strata of fossils was older and younger
** Discours sur la Théorie de la Terre (1825)
* Jean-Baptiste Lamarck (1744-1829) - urged naturalists to describe the natural world, without wasting time on theories purporting to explain it.

== Enlightened Science I: Chemistry Catches Up ==
* The basic feature of the Enlightenment was a belief in the superiority of reason over superstition. This incorporated the idea that humankind was in the process of progressing socially, so that the future would be an improvement of the past; and one of those improvements was a challenge to orthodox religion with its overtones of superstition. Both the American and the French revolutions were justified intellectually, in part, on the basis of human rights, a guiding principle of Enlightenment philosophers such as Voltaire and activists such as Thomas Paine. The success of Newtonion physics in providing a mathematical description of an ordered world clearly played a big part in the flowering of this movement in the 18th century, encouraging philosophers of a rationalist persuasion, and also encouraging chemists and biologists to think that their parts of the natural world might be explained on the basis of simple laws.
* The idea of order and rationality as a way to investigate the world had taken root by the early 18th C and seemed the obvious way forward.
* The Industrial Revolution probably took place first in England (around 1740-1780 due to Britain being an « island of coal » but also because the Newtonian mechanistic world became firmly established there. The IR stimulated interest in topics like heat and thermodynamics (the connection between heat and motion) and provided new tools for scientists to use in their investigations of the world.
* Astronomy, physics, botany, and zoology could make progress with simple tools, but chemists needed, above all, a reliable and controllable source of heat to encourage chemical reactions.
* Gabriel Fahrenheit (1686-1736)- Invented the alcohol thermometer in 1709, the mercury thermometer in 1714 (along with the Fahrenheit scale).
* Anders Celsius (1701-1744) - came up with his scale in 1742.
* Thomas Newcomen (1663-1729) - Completed the first practical steam engine to pump water from mines in 1712
* From the 1740s onward, progress was rapid (if sometimes confused).
* William Cullen (1710-1790) - Invented the first refrigerator.
* Joseph Black (1728-1799):
** Discovered carbon dioxide and showed for the first time that air is a mixture of gases and not a single substance.
** Using his usual careful, quantitative approach, made a crucial distinction between the concepts of heat and temperature.
** Gave the name « specific heat » to the amount of heat required to raise the temperature of a certain amount of a chosen substance by a certain amount.
* James Watt (1736-1819)
** First person to take a set of ideas from the cutting edge of then-current research in science and apply them to make a major technological advance.
** The scale effect - a small object loses heat more rapidly than a large object of the same shape because the small object has a larger surface area, across which heat escapes, in proportion to its volume, which stores heat.
* He improved on Newcomen’s steam engine by using two cylinders, one which was kept hot (in which the piston moved) and one which was kept cold.
** Patented his steam engine in 1769.
* Joseph Priestley (1733-1804):
** Wrote a history of electricity in1767.
** When he began, only two gases (« air » and carbon dioxide (« fixed air ») were known.
** Identified another ten gases, including ammonia, hydrogen choloride, nitrous oxide (laughing gas) and sulphur dioxide.
** Greatest discovery was Oxygen (in 1774) - explaining it in terms of the philogiston model. This model would be doomed when people started noticing that things get heavier when they burn, not lighter.
** Discovered carbon dioxide over a brewers vat and invented « soda water », a craze for which spread across Europe.
** Showed how the ability of air to sustain life would somehow be « used up » in respiration and that the respirability of the air could be restored by the presence of planes - the first hints of the process of photosynthesis in which carbon dioxide is broken down and oxygen is released.
* Carl Scheele (1742-1786) - Realized that air is a mixture of two substances, one of which prevents burning, while the other promotes combustion.
* Science progresses incrementally, building on what has already been discovered and making use of the technology of the day.
* Henry Cavendish (1731-1810):
** The Cavendish Laboratory in Cambridge, built in the 1870s is named after him.
** Discovered Hydrogen (« inflammable air ») in 1776. He thought that the gas was released by the metals involved in the reaction (we now know that it comes from the acids), and thought that it was phlogiston.
** Showed that water was not an element and is somehow formed from a mixture of two other substances, a key step in the transformation of alchemy into chemistry.
** Found a previously unknown gas, argon, present in tiny traces (0.93%) in the atmosphere.
** In « the Cavendish experiment », weighed the Earth using a torsion balance.
* Antoine Lavoisier (1743-1794):
** Thought of as the greatest chemist of all
** Showed that diamond is combustible.
** Showed that sulphur gains weight when it burns, his first, independent, step to the modern understanding of combustion as a process involving oxygen from the air combining with the substance that is being burnt.
** Gave oxygen its name (in 1779)
** Coming towards the idea that animals keep warm by converting carbon (from their food) into carbon dioxide (which they breathe out) by combining it with oxygen from the air (which they breathe in), seeing respiration as a very slow form of combustion. This was a key step in setting human beings in their context as complicated systems obeying the same laws as falling stones or burning candles, and showed that there was no need to invoke anything outside the known world of science to produce the life-associated warmth of the human body - no need for Harvey’s « natural heat ».
** First person to appreciate that water is a compound substance formed from a combination of « inflammable air » and oxygen in the same sort of way that « fixed air » is formed from a combination of carbon and oxygen.
** Elements of Chemistry (1789) - which laid the foundations for chemistry as a genuinely scientific discipline and almost an equivalent to chemistry of newton’s Principia to Physics. Marks the moment when chemistry becomes recognizable as the discipline of today.
** Proposed new names based on a logical system of nomenclature (such as oxygen, hydrogen, and sulphuric acid), introduced a logical way to name compounds, such as nitrates. By giving chemistry a logical language, he greatly eased the task of chemists trying to communicate their discoveries to one another.
** Guillotined on 8 May 1794.

== Enlightened Science II: Progress on All Fronts ==

* In the decade following the death of newton, the term « Physics » started to be used in plae of « natural philosophy.
* Pieter van Musschenbrook (1692-1761):
** « Essaie de Physique » (1737 - one of the first books to use the term in its modern sense
** Invented the Leiden Jar - a device that could store large quantities of electricity
* First steps towards an understanding of static elecricity.
* There are two kinds of electricity (positive and negative charge) and similar kinds repel one another while opposite kinds attract.
* The importance of insulating material in preventing electricity draining away from charged objects.
* Benjamin Franklin (1706-1790):
** Developed a one fluid model of electricity where a physical transfer of the single fluid occurs when an object becomes electrically charged, leaving one surface with « negative » charge and the other with « positive » charge. ie, charge is conserved - there is always the same amount of electricity, but it can be moved around, and overall the amount of negative charge must balance the amount of positive charge.
** Showed that electricity can magnetize and demagnetize iron needles.
* Charles Coulomb (1736-1806) - Convinced everyone that both electrical and magnetic forces obey an inverse square law - now coulomb’s law.
* Luigi Galvini (1737-1è98) - twitching of frog’s legs is caused by electricity stored or manufactured in the muscles of the frog.
* Alessandro Volta (1745-1827):
** Created the voltaic pile, forerunner of the modern battery. Beore this, the study of electricity was essentially confined to the investigation of static electricity. After 1800, physicicists could work with electric currents, which they could turn on and off at will.
** Current from such a pile could be used to decompose water into hydrogen and oxygen.
* Pierre-Louis de Maupertuis (1698-1759):
** The principle of least action - nature is lazy. Eg, light always travels in straight lines.
* Leonhard Euler (1707-1783) - regarded as the most prolific mathematician of all time.
** Introduced the use of the letters e and i
** Described mathematically the refraction of light.
* William (1738-1822) and Caroline (1750-1848) Herschel discovered Uranus, the first planet that had not been known to the ancients.
* John Michell (1724-1793) - first person to come up with the idea of what are now known as black holes in a paper read to the Royal Society in 1783.
* Pierre Simon Laplace (1749-1827)
** Explained variations in planetary orbits follow a cycle 929 years long (so the Solar System is stable after all.
** Exposition du système du monde (1796) - one of the most influential books about science ever published, summing up where physics stood at the end of the 18th C. « The simplicity of nature is not to be measured by that of our conceptions. Infinitely varied in its effects, nature is simple only in its causes, and its economy consists in producing a great number of phenomena, often very complicated, by means of a small number of general laws.
** Nebular hypothesis of the origin of the Solar System - it was practically certain that the planets had formed together from a cloud of material around the young Sun, shrinking down into a plane as the cloud, or nebula, contracted.
** Laplace’s version of black holes.
* One reason why science did progress so rapidly in the 19th C was that by the end of the 1790s it was obvious to all but the most blinkered of the old school that the ideas of phlogiston and caloric wer both dead and buried.
* James Hutton (1726-1797):
** Develops the idea of uniformitarianism - that the same uniform processes are at work all the time and mould the surface of the Earth continually. The idea that occasional great acts of violence are needed to explain the observed features of the Earth become known as catastrophism. Previously the received wisdom was a combination of catastrophism and Neptunism.
** Theory of the Earth (1795). John Playfair wrote a masterly, clear summary of it in 1802 as Illustrations of the Huttonian Theory of the Earth.

== The Darwinian Revolution ==
* Arguably the most important idea in the whole of science. This is the nub of the theory of natural selection:
** Offspring resemble their parents, but in each generation there are slight differences between individuals.
** Only the individuals best suited to the environemnt survive to reproduce, so the slight differences which make them successful are selectively passed on to the next generation and become the norm.
** When conditions change, or when species colonize new territory, species change to match the new conditions and new species arise as a result.
** Natural selection explains how, given enought time, evolution could produce an antelope adapted to a grazing lifestyle, the grass itself, a lion adapted to eat antelope, a bird that depends on a certain kind of seed for its food, or any other species on Earth today, including humankind, from a single, simple common ancestor.
* Charles Lyell (1797-1875):
** Principles of Geology (1830) - Third volume in 1833, 12th and final in 1875
** The first person to make his living as a science writer.
** Elements of Geology (1838)
** The leading geologist of his time
** In 1841 went on a year-long visit to the US by steamship, and was surprised how the railways had already spread over what was until recently unknown territory.
* Evolutionary ideas can be traced back to the ancient Greeks, and there were discussions about species change by Francis Bacon in 1620 and Leibnitz, while Buffon also discussed the migration and evolution of species. The difference with Darwin and Russel was that they came up with a sound scientific theory.
* Erasmus Darwin (1731-1802):
** Zoonomia (1794, 1796) in two volumes sets out his ideas on evolution.
** God still exists for Erasmus, but only as the first cause who set the processes of life on Earth working. There is no place here for a God who intervenes to create new species from time to time, but a clear sense that whatever the origins of life itself, once life existed it evolved and adapted in accordance with natural laws, with no outside intervention.
* Jean-Baptiste Pierre Antoine de Monet de Lamarck (1744-1829):
** Flore française (1778)
** Classified insects and worms into « invertebrates ».
** Histoire naturelle des animaux sans vertèbres (7 volumes) (1815-1822):
** His four laws - which become progressively more wrong:
*** First law - By virtue of life’s own powers there is a constant tendency for the volume of all organic bodies to increase and for the dimensions of their parts to extend up to a limit determined by life itself. (true)
*** The production of new organs in animals results from newly experienced needs which persist, and from new movements which the needs give rise to and maintain (not wrong but Lamarck means, wrongly, that the new organs develop within individuals, not by tiny changes from one generation to the next)
*** Third Law: The development of organs and their faculties bears a constant relationship to the use of the organs in question (definitely wrong - the idea that the giraffe’s neck gets long because it is stretching for leaves)
*** Fourth Law: Everything which has been acquired or changed in the organization of an individual during its lifetime is preserved in the reproductive process and is transmitted to the next generation by those who experienced the alterations (definitely wrong)
* Charles Darwin (1809-1882)
** Learned about the argument between the Neptunists, who thought that the Earth’s features had been shaped by water, and the Vulcanists, who saw heat as the driving force - he preferred the latter explanation.
** 1831 - start of a 5 year voyage on the Beagle
** The Voyage of the Beagle (1839)
** Calls the great age of the Earth, « the gift of time »
** On the Origin of Species by Means of Natural Selection (1859) - prompted by Lyell’s advances
* Thomas Malthus (1766-1834):
** Britain’s first professor of political economy.
** Essay on the Principle of Population (1798) - populations have the power to grow geometrically, but are held in check by pestilence, predators, and especially by the limited amount of food available (as well as by war, in the case of humans). Most offspring die without reproducing, if nature takes its course.
* Alfred Russel Wallace (1823-1913)
** 1847 - self-funded a four year , two-man expedition to South America, exploring and collecting in the jungles of Brazil.
** The great problem of the origin of species was already distinctly formulated in my mind… I firmly believed that a full and careful study of the facts of nature would ultimately lead to a solution of the mystery
** 1854 - goes to the Far East because he decided that the best way to pursue his interest in the species problem would be to visit a region of the globe which had not already been explored by other naturalists.
** Stays there for eight years, publishing 40 scientific papers, and establishing the geographical ranges of different species
** Wallace developed the idea of evolution as like the branching of a huge tree, with different branches growing from a single trunk, and continually dividing and splitting down to the little twigs, still growing, which represent the diversity of living species (all derived from a common stock) in the world today. He presented these ideas in 1855 without, at that point, offering an explanation for how or why speciation occurred.
** Breakthrough in 1858, remembering Malthus - in every generation the inferior would inevitably be killed off and the superior would remain.
** On the Tendency of Varieties to Depart Indefinitely from the Original Type (1858)
* Thomas Henry Huxley (1825-1895)
** Darwin’s bulldog
** Helped to establish science as a profession that people were paid to do.
* Darwin was the first scientist listed here who was born after 1800. Wallace was the first who dies after 1900.

== Atoms and Molecules ==
* During the 19th C, science shifts from being a gentlemanly hobby to a well-populated profession
* Humphry Davy (1778-1829):
** Learned French and red Lavoisier’s Traité Elémentaire in the original French
** Carried out experiments with nitrous oxide (laughing gas) and discovered that it could be used during surgical operations
** Saw a significant relationship between chemistry and electricity.
** Royal Instituation established by Count Rumford in 1799 and he became its director in 1802
** One of the last great amateur scientists and also one of the first professional ones.
** 1806 - Isolated two previously unknown metals and called them potassium and sodium.
** 1810 - isolated and named chlorine. Defined an element as a substance that cannot be decomposed by any chemical process, showed that chlorine is an element, and established that the key component of all acids is hydrogen, not oxygen.
** Appointed Michael Faraday (his eventual successor) as an assistant in the RI
** Designed the famous miners’ safety lamp which bears his name.
** In 1820, elected President of the Royal Society
* John Dalton (1766-1844)
** When he was born, there were perhaps 300 scientists in the world, when he started work there were a thousand, by his death 10k, and by 1900 100k. The number of scientists doubled every 15 years (though generally populations were doubling over longer periods)
** Recorded daily meteorological observations daily from 1787 until his death.
** Discussed the nature of water vapour and its relationship to air, describing it in terms of particles which exist between the particles of air, so that the equal and opposite pressures of the surrounding air particles on a particule of vapour cannot bring it nearer to another particle of vapour, without which no condensation can take place - a precursor to his atomic theory.
** Was color-blind and did a detailed analysis of the condition, which became known as Daltonism
** In 1801, came up with the law of partial pressures, which says that the total pressure exerted by a mixture of gases in a container is the sum of the pressures each gas would exert on its own under the same conditions.
** In the early 1800s became convinced that each element was made up of a different kind of atom, what made one element different from another was the weight of its atoms, and that elementary atoms could be neither created nor destroyed (though they could combine to form « compound atoms » (molecules).
** The main flaw in the model is that he did not realize that elements such as hydrogen are composed of molecules, not individual atoms and so he got some combinations wrong.
** A New System of Chemical Philosophy (1808)
* It took almost half a century for the Daltonian atom to become really fixed as a feature of chemistry
* Jöns Berzelius (1779-1848):
** One of the first people to formulate the idea that compounds are composed of electrically positive and negative parts
** Studied 2000 different compounds over 6 years
** Invented the modern alphabetical system of nomenclature for the elements.
** Isolated and identified several elements, including selenium, thorium, lithium and vanadium
** Chemists were beginning to group elements into families with similar properties. He gave the name « halogens » (meaning salt-formers) to the group including chlorine, bromine, and iodine.
** Coined the terms « organic chemistry », « catalysis », and « protein »
** Textbook of Chemistry (1803)
** Experimenters had long been aware that everything in the material world falls into one of two varieties of chemical substances. Some can be heated and seem superficially to change their character (glowing red hot, melting, evaporating, etc), but when cooled, revert back to the same chemical state they started from. Others, such as sugar or wood, are completely altered by the action of the heat, so that it is very difficult to « unburn » a piece of wood. In 1807, he formalized the distinction. The first, associated with non-living systems, he called « inorganic », and the second, associated with living systems, « organic ». It became clear that organic materials are made up of much more complex compounds, but there was also belief in a vague « life force ».
* Joseph Louis Gay-Lussac (1778-1850)
** In 1809 published that gases combine in simple proportions by volume, and that the volume of the products of the reaction (if they are also gaseous) is related in a simple way to the volumes of the reacting gases.
* Amadeo Avogadro (1776-1856):
** In 1811, gave the hypothesis that at a given temperature, the same volume of any gas contains the same number of particles.
** Realized that oxygen and other elements could exist in polyatomic molecular form. Two volumes of hydrogen contain twice as many molecules as one volume of oxygen, and when they combine, each oxygen molecule provides one atom to each pair of hydrogen molecules, making the same number of molecules as there were in the original volume of Hydrogen.
* William Prout (1785-1850):
** Suggested that the atomic weights of all elements are exact multiples of the atomic weight of hydrogen, implying that in some way heavier elements might be built up from hydrogen.
** In the 20th C, with the discovery of isotopes (atoms of the same element with slightly different atomic weights, but each isotype having an atomic weight a precise multiples of the weight of one hydrogen atom) the puzzle was resolved (since chemically-determined atomic weights are an average of those of all the isotopes of an element present, and Prout’s hypothesis was confirmed.
* Friedrich Wöhler (1800-1882):
** Accidentally discovered that organic materials could be manufactured from substances that had never been associated with life and the definition of organic changed. There was no mysterious life force.
** Organic compounds are often complex, containing elements of different elements, and they all contain carbon, which is the reason for their complexity.
* Now we say that an organic molecule is any molecule containing carbon and organic chemistry is the chemistry of carbon and its compounds. Life is seen as a product of carbon chemistry, obeying the same chemical rules that operate throughout the world of atoms and molecules. Natural selection tells us that we are part of the animal kingdom with no evidence of a uniquely human soul. Chemistry tells us that animals and plants are part of the physical world, with no evidence of a special « life force ».
* Edward Frankland (1825-1899)
** Analyzed valency, a measure of the ability of one element to combine with another or as soon became clear, the ability of atoms of a particular element to combine with other atoms.
* Archibald Couper (1831-1892):
** Introduced the concept of « bonds », simplifying the representation of valency. Hydrogen is now said to have a valency of 1, meaning that it can form one bond with another atom. Oxygen has a valency of 2, meaning that it can form two bonds. Nitrogen has a valency of 3 and carbon has a valency of 4, so it can form four separate bonds with four separate atoms, including other atoms of carbon at the same time.
** He saw that organic chemistry might consist of a chain of carbon atoms holding hands with other atoms attached to the spare bonds at the sides of the chain.
* Friedrich August Kekulé (1829-1896):
** Saw that carbon atoms could link up in rings (often six atoms in a hexagon) with bonds sticking out from the ring to link up with other atoms or other rings of atoms.
* Stanislao Cannizzaro (1826-1910)
** Drew the essential distinction between atoms and molecules
** Showed how the observed behavior of gases together with Avogadro’s hypothesis could be used to calculate atomic and molecular weights relative to the weight of one hydrogen atom, and drew up a table of atomic and molecular weights.
* John Newlands (1837-1898):
** Realized that if the elements are arranged in order of their atomic weight, there is a repeating pattern in which elements at regular intervals, with atomic eights separated by amounts that are multiples of eight times that of hydrogen, have similar properties.
* Dmitri Mendeleev (1834-1907):
** Principles of Chemistry (1868, 1870)
** On the Relation of the Properties to the Atomic Weights of Elements
** Rearranges the elements slightly in order to make them fit the pattern he had discovered and leaves gaps in the periodic table for elements which had not yet been discovered.
** It turns out that the chemical properties of an element depend on the number of protons in the nucleus of each atom (the atomic number), while its atomic weight depends on the total number of protons plus neutrons in the nucleus
** By 1871 he had refined his table to incorporate all of the 63 known elements, with three gaps, which would be filled over the next 15 years with just the properties predicted by him - gallium (1875), scandium (1879) and germanium (1886)
** From a mass of data, Mendeleyev found a pattern and made a prediction that could be tested by experiment, and found a deep truth about the nature of the chemical world.
* Themodynamics frew out of the industrial revolution and fed back into it. At the beginning of the 19th C, there was no consensus about the nature of heat, the term was coined in 1849 by William Thomson, by the 1860s the basis laws and principles had been worked out, and 40 years later would be used in a definitive proof of the reality of atoms.
* Sadi Carnot (1796-1832)
** Réflexions sur la puissance motive du feu (1824) - analyzed the efficiency of engines converting heat into work, provided a scientific definition of work, showed that work is done as heat passes from a higher temperature to a lower temperature, and even suggested the possibility of the internal combustion engine.
** First person to appreciate that heat and work are interchangeable and worked out how much work a given amount of heat can do.
Julius Robert von Mayer (1814-1878):
** Knew Lavoisier’s work which showed that warm-blooded animals are kept warm by the slow combustion of food, which acts as fuel, with oxygen in the body. He knew that bright red blood, rich in oxygen, is carried around the body from the lungs in arteries, while dark purple blood, deficient in oxygen, is carried back to the lungs by veins.
** Realized that the reason why the venous blood was rich in oxygen was that in the heat of the tropics the body had to burn less fuel (and therefore consume less oxygen) to keep warm. He saw that this implied that all forms of heat and energy are interchangeable - heat from muscular exertion, the heat of the Sun, heat from burning coal, or whatever - and that heat, or energy, could never be created but only changed from one form to another.
* James Joule (1818-1889):
** Gave two lectures in Manchester in 1847 setting out the law of conservation of energy and its importance to the physical world.
** The Joule-Thomson effect - the way in which gases cool as they expand, the principle on which a refrigerator operates.
* William Thomson/Lord Kelvin (1824-1907):
** Responsible for the success of the first working transatlantic telegraph cable
** Established thermodynamics as a scientific discipline in the middle of the 19th C.
** Established the absolute scale of temperature, which is based on the idea that heat is equivalent to work, and that a certain change in temperature corresponds to a certain amount of work. There is a minimum possible temperature (-273C) at which no more work can be done because no heat can be extracted from a system.
* Laws of thermodynamics:
** First law - heat is work
** Second law - Heat cannot, of its own volition, move from a colder object to a hotter object. Things wear out - everything wears out, including the Universe itself
** Writes in 1852: Within a finite period of past time the earth must have been, and within a finite period of time to come the earth must again be unfit for the habitation of man as at present constituted, unless operations have been or are to be performed which are impossible under the laws to which the known operations going on at present in the material world are subject.
** This was the first real scientific recognition that the Earth (and, by implication, the Universe had a definite beginning. He worked out the age of the sun as at least a few tens of millions of years based on the most efficient processes for generating heat known at the time (until the later discovery of radiation).
* Rudolf Clausius (1822-1888)
** Defined « entropy ». it always increases. It is only possible for order to be preserved or to increase in local regions, such as the Earth, where there is a flow of energy from outside (ie the Sun) to feed off. But it is a law of nature that the decrease in entropy produced by life on earth feeding off the Sun is smaller than the increase in entropy associated with the processes that keep the Sun shining, whatever they may be. This cannot go on for ever - the supply of energy from the Sun is not inexhaustible.
** Introduced the idea of a mean free path - the average distance that a molecule travels between collisions, and it is tiny. Every molecule experiences more than 8bn collisions per second. It is the shortness of the mean free path and the frequency of these collisions that gives the illusion that a gas is a smooth, continuous fluid, when it is really made up of a vast number of tiny particles in constant motion with nothing at all in the gaps between the particles. This led to a full understanding of the relationship between heat and motion - the temperature of an object is a measure of the mean speed with which the atoms and molecules that makeup the object are moving - and the final abandonment of the caloric
* James Clerk Maxwell (1831-1879):
** Applied Clausius’s ideas to explain many of the observed properties of gases, such as their viscosity and the way they cool when they expand (because atoms and molecules in a gas attract one another slightly, so work has to be done to overcome this attraction when the gas expands, slowing the particles down and therefore making the gas cooler)
** Maxwell-Boltzmann distribution - statistical rule describing the distribution of the velocities (or kinetic energies) of the molecules in a gas around their mean.
* Albert Einstein (1879-1955):
** Obsessed with the idea of proving that atoms are real.
** Used the second law or the tendency of all differences in the Universe to average out. A system in which there is a clear pattern (or even a vague pattern) has more order, and therefore less entropy, than a system in which there is no pattern. Nature abhors differences.
** Osmetic pressure depends on the number of molecules of the solute (in this case sugar) in the solution. The more concentrated the solution, the greater the pressure.
** Einstein explained Brownian motion, the jerky, zig-zag fashion of grains in water. The motion might be caused by the impact of molecules with the grains. A better way might be in statistical terms. The process is now known as a « random walk » and the statistics behind it turn out to be important, for example, in describing the decay of radioactive elements.
** The blue color of the sky is caused by the way light is scattered by the molecules of gas in the air itself.

== Let There Be Light ==
* Francesco Grimaldi (1618-1663)
** Diffraction - direct evidence that light travels as a wave
* Euler published his model of light in 1746 and specifically made the analogy between light waves and sound waves and described the Sun as « a bell ringing out light »
* Thomas Young (1773-1829)
** Explained the focusing mechanism of the eye (the way muscles change the shape of the lens of the eye)
** Explained astigmatism as an uneven curvature in the cornea.
** First person to appreciate that color vision is produced by a combination of three primary colors (red, green, and blue) which affect different receptors in the eye and explained color blindness as a failure of one or more sets of these receptors
** Played a leading role in deciphering the Rosetta Stone.
** « Outlines of Experiments and Enquiries Respecting Sound and Light » (1800) - proposing that different colors of light correspond to different wavelengths.
** The idea of interference in light waves (like interfering ripples on a pond).
** Calculated the wavelength of red and violet light
** Young’s double slit experiment - where there can be dark where the peaks and troughs of two light waves cancel each other out.
* Augustin Fresnel (1788-1827):
** Developed an efficient lens made of concentric annular rings of glass, each with a slightly different curvature (the Fresnel lens)
* William Wollaston (1766-1828):
** Discovered the elements rhodium and palladium
* Josef von Frauenhofer (1787-1826):
** Frauenhofer lines
** Diffraction grating
** Counted 576 dark lines between the red and violet ends of the spectrum and proved that they were a property of the light itself
* Robert Bunsen (1811-1899) and Gustav Kirchoff (1824-1887):
** Each element, when hot, produces a characteristic pattern of bright lines in the spectrum, like the pair of yellow lines associated with sodium. Each pattern is as distinctive as a fingerprint or a barcode.
* Norman Lockyer (1836-1920):
** Identified Helium based on the fact that it had an unknown fingerprint.
* Michael Faraday (1791-1867):
** Oersted had discovered in 1820 that there is a magnetic effect associated with an electric current and when a magnetic compass needle is held over a wire carrying an electric current it is deflected to point across the wire at right angles.
** Faraday realized that the wire should be forced to move in a circle around a fixed magnet - « The effort of the wire is always to pass off at a right angle from the pole of the magnet, indeed to go in a circle around it.
** This is the basis of the electric motor - sixty years later, electric trains were running in Germany and the USA.
** Liquefies chlorine in 1823.
** Discovers benzene in 1825, which had the archetypal ring structure of importance to the molecules of life.
** If an electric current can induce a magnetic force, can a magnet induce an electric current.
** An electric current passing through a wire wound in a helix/coil would make it act like a bar magnet with poles, and if it is wound round an iron rod, the rod becomes a magnet when the current is turned on.
** Invented the electric generator or dynamo, which uses the relative motion of coils of wire and magnets to generate electric currents.
** Introduced terms « electrolyte », « electrode », « anode », « cathode », and « ion ».
** Introduced concept of « lines of force » in 1831
** In 1832, suggested that magnetic forces take time to travel across space, proposing that a wave motion was involved and making a tenuous connection with light
** Magnetic, electric, and gravitational lines of force filled the Universe, according to Faraday, and were the reality with which the seemingly material entities that make up the world are interconnected. The material world, from atoms to the Sun and Earth and beyond, was simply a result of knots in the various fields.
* James Clerk Maxwell (1831-1879):
** Definitively explained light as an electromagnetic phenomenon
** His work on color vision was the foundation for color photography, for color TV and computer monitors.
** Published a set of four papers On Physical Lines of Force (1861-2) - « light consists in the transverse undulations of the same medium which is the cause of electric and magnetic phenomena. »
** « A Dynamical Theory of the Electromagnetic Field » (1864) - summed up all of classical electricity and magnetism in four equations (Maxwell’s equations). This unified electricity and magnetism in the electromagnetic field.
** Placed alongside Newton in the pantheon of great scientists - Newton’s laws and Maxwell’s equations explained everything known to physics at the end of the 1860s.
** Introduced the constant c, which is the speed of light (299,792,458 m/s) - Light (including radiant heat and other radiations, if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to electromagnetic laws;
** Predicted radio waves.
** « Treatise on Electricity and Magnetism » (1873)
** Set up and led the Cavendish Laboratory from 1874.
* Heinrich Hertz (1857-1894)
** Confirmed the existence of radio waves, showing that they travel at the speed of light and can be reflected, refracted and diffracted.

== The Last Hurrah of Classical Science ==
* Radioactivity is discovered at the end of the 19th C, turning geology into geophysics, providing a way to keep the Earth warm inside for long enough (and stars shining long enough) to support the increasingly long estimates of the age of the Earth (and the Universe).
* Radioactivity howed that the Earth's interior was not, in fact, cooling dramatically at all
* Permanentism held that continents were always continents and oceans always oceans, while contractionism was a variant of catastrophism
* Eduard Suess (1831-1914):
** Proposed that Australia, India and Africa were fragments of Gondwanaland, an ancient landmass.
* Alfred Wegener (1880-1930):
** Father of the theory of continental drift
** Greenland expedition in 1912-3
** "The Origin of Continents and Oceans" (1915)
** Saw that the continents and ocean floors are fundamentally different
** Proposed that there was once a single supercontinent, Pangea, which had broken up to create today's continents, but had no reason for its breakup.
** Died on second Greenland expedition in 1930
* We now know that the Atlantic is widening at a rate of a few centimeters a year
* Arthur Holmes (1890-1965)
** More than any other, "the man who measured the age of the Earth".
** "Principals of Physical Geology" (1944) - a nod to Lyell
** Apart from the radioactive heating, the key component was time - "solid" rock, warmed from beneath, could stretch and flow, like very thick treacle, but only very slowly. Convection currents inside the Earth, coming from heat generated by radioactive decay broke up Pangea. These currents would move continents at a rate of about 5cm/yr, so the Atlantic could be made from an initial crack over a period of about 100m years.
* In the early 20th C can now date sample of rock from the proportions of lead and uranium isotopes they contain, and these rocks ere much older than would be allowed by the idea of heat being released from the Sun only as a result of its gravitational collapse.
* Walter Elsasser (1904-1991):
** The Earth's magnetism is generated by a natural internal dynamo
* Edward Bullard (1907-1980):
** The Earth's magnetic field is the product of circulating conducting fluids in the hot fluid core (basically convection and rotation in molten iron)
** The "Bullard fit" of the continents, published in 1965, shows them all stuck together in a single landmass.
* Rocks are magnetised when they are laid down, as molten material flowing from volcanoes or cracks in the Earth's crust, and once set they preserve the pattern of the magnetic field in which they formed, becoming like bar magnets, but realized that not all rocks are magnetized in the same direction and there is evidence that the geomagnetic field had flipped at some time in the past. Maybe this is due to the core's dynamo dying out and then building again in the opposite sense. The Sun also has magnetic reversal every 11 years or so, linked to the sun spot cycle.
* Much more knowledge of the sea bed, which is two-thirds of the Earth's surface.
* In the 1960s, see the ocean basins as the sites of action in continental drift with the continents being just carried along for the ride.
* The Atlantic is getting wider and the Pacific is narrowing. Eventually, America and Asia will collide, while the Red Sea is a new region of upwelling activity, which will splinter Africa away from Arabia to the east.
* The sea floor spreading is like a slow conveyor belt, endlessly looping round and round, but over the surface of the planet, everything cancels out and the planet stays the same size.
* Tuzo Wilson (1908-1993) - Coined the term "plate" for the rigid portions of the Earth's crust.
* Plate tectonics - seismically quiet regions of the globe are quiet because they form rigid plates (six large ones and about twelve small ones, covering the entire surface of the globe):
** An individual plate may be just oceanic crust, just continental crust, or both.
** Most of the interesting geological activity on Earth is happening at the boundaries between plates (plate margins).
** Constructive margins are where new oceanic crust is being made at ocean ridges and spreading out on either side.
** Destructive margins are where one plate is being pushed under the edge of another, going down at an angle of 45 degrees and melting back into the magma below
** Conservative margins are where plates are merely rubbing sideways against each other as they rotate (eg San Andreas Fault)
** Mountain ranges and former sea beds in the hearts of continents today, show that this activity has been going on since long before the breakup of Pangea, and that supercontinents have repeatedly broken up and rebuilt in different patterns.
* Louis Agassiz (1807-1873):
** Coined the term "Ice Age"
** "Studies on Glaciers" (1840)
** Compared to a Great Flood, glaciation was uniformitarian.
* Joseph Adhémar (1797-1862):
** "Revolutions of the Sea"
** On 4 July each year, the Earth is furthest from the Sun and is moving at its slowest, and on 3 January it is at its closest, but the difference is only about 3% of the average 150km distance.
** The Earth wobbles like a spinning top over the course of each 22k years, suggesting an alternating cycle of ice ages in the northern and southern hemispheres, but this last point turns out to be wrong
* Climate is determined by the distance of a planet from the Sun, the latitude of interest, and the angle at which the Sun’s rays strike the surface at that latitude. The key to Ice Ages is cool summers, not extra-cold winters. The last Ice Ages was intense about 80,000 years ago and ended about 10-15k years ago.
* The natural state of the Earth throughout most of its long history has been completely ice-free. But occasionally, at intervals separated by hundreds of millions of years, one or other hemisphere is plunged into a period of cold lasting for several million years, an Ice Epoch. There was an Ice Epoch lasting for about 20m years in the Permian and ending about 250m years ago
* After the Permian Ice Epoch ended, the world was warm for 200m years, while the dinosaurs flourished, but it started cooling again 55m years ago and by 10m years ago, glaciers returned.
* For the last 5m years, the Earth has been in what may be a unique state, with ice caps over both poles. In this period we have seen a succession of full Ice Ages about 100k years long, separated by warmer Interglacials like the present day, lasting about 10k years. The present Interglacial could be coming to an end naturally in a couple of thousand years — less time than the span of recorded history.
* It may be this unusual sequence of Ice Ages and Interglacials caused by continental drift that provided suitable selection pressures for us to break away from our hominid cousins and ratchet up our intelligence and adaptability as the key requirements for survival on the fringes of forests.

== Inner Space ==
* Heinrich Geissler (1814-1879)
** Invented the vacuum tube, technology that led to the discovery of electrons ("cathode rays") and X-rays.
* William Crookes (1832-1919)
** Developed an improved vacuum tube known as the Crookes tube, with an even better (harder) vacuum
* JJ Thomson (1856-1940)
** Found that cathode rays move much more slowly than light.
** 1897 is often regarded as the year of the "discovery" of the electron - the atom was definitely not indivisible
* William Röntgen (1845-1923):
** Discovered X-rays, which are not deflected by electric or magnetic fields, though they are a form of electromagnetic wave with wavelengths much shorter than visible light (or even ultraviolet light)
* Henri Becquerel (1852-1908
** Phosphorescent salts can produce energy, it seems, out of nothing at all.
* Marie Curie (1867-1934)
** In 1898 discovered that pitchblende is more radioactive than uranium, and must contain another, highly radioactive, element.
** Discovered polonium and radium
** discovered that radium outputs enough energy to heat gram after gram of water to boiling point seemingly endlessly.
* Ernest Rutherford (1871-1937)
** Found that the radiation discovered by Becquerel is made up of two components, alpha radiation (with a short range) and beta radiation (with a much longer range and more penetrating power).
** Discovered that during radioactive decay, an atom is converted into an atom of a different element
** Pointed out that this storehouse of energy gave the Earth a possible lifetime of at least hundreds of millions of years
** Alpha particles are the same as helium atoms which have lost two units of negative electric charge (they have lost two electrons)
** Most of the mass and charge of an atom is concentrated in a tiny central nucleus, surrounded by a cloud of electrons.
** An individual alpha particle weights 8000 times as much as an individual electron. The nucleus occupies only about one hundred-thousandth of the diameter of an atom, which is mostly empty space, filled with a web of electromagnetic forces linking the positive and negative charges.
** Everything we think of as solid matter is mostly empty space.
** Nitrogen atoms bombarded with alpha particles were converted into a form of oxygen, with the ejection of a hydrogen nucleus (a proton). This was the first artificial transmutation of an element, and marked the beginning of nuclear physics.
** By 1920, experiments involving just a few atoms were becoming routine.
** Beryllium exposed to alpha particles produced a new form of radiation explained in terms of gamma rays. The alpha radiation was knocking neutral particles out of the beryllium nuclei, and these neutral particles were in turn knocing protons (hydrogen nuclei) out of the paraffin
* Max Planck (1858-1947)
** h is Planck's constant
* Albert Einstein (1879-1955)
** Found that electromagnetic radiation behaves as if it consisted of mutually independent energy quanta
** Light could be seen behaving either as a wave (the double-slit experiment) or as a stream of particles (the photoelectric effect). How could this be?
* Niels Bohr (1885-1962)
** The reason why atoms are stable is entirely thanks to quantum physics.
** Said that electrons had to stay in their orbits around the nucleus because they are not physically capable of continuously emitting radiation, as they would be if classical laws applied. An electron can only emit quanta of energy, one at a time, and this would correspond to it jumping down from one orbit to another.
** Each allowed orbit had room for only a certain number of electrons, and that electrons further out from the nucleus cannot jump inwards if the inner orbits are already full.
* Louis de Broglie (1892-1987):
** Just as electromagnetic waves could be described in terms of particles, all material particles, such as electrons, could be described in terms of waves.
** The momentum of a particle multiplied by its wavelength is equal to Planck's constant.
** Everything has dual wave-particle character, but the wave aspect scarcely matters at all above the molecular level (though it cannot entirely be ignored for whole atoms)
* Schrôdinger, Heisenberg, and Dirac:
** The uncertainty principle - we cannot know, as a matter of principle, the present in all its details. The size of the smallest electron orbit in an atom is as small as it can be without violating the uncertainty principle.
** Existence of a previously unknown particle, with the same mass as an electron but positive charge - the positron or antimatter.
** The strong nuclear force (or strong force) is 100x stronger than the electric force, which is why there are about a hundred protons in the largest stable nuclei; any more, and electric repulsion overcomes the strong force and blows the nucleus apart. But the strong force, unlike electric, magnetic, and gravitational forces, does not obey an inverse square rule. It is very strong indeed over an extremely limited range, and cannot essentially be felt at all beyond that range.
* Wolfgang Pauli and Enrico Fermi
** The weak nuclear force and the neutrino.
* Atoms are made of protons, neutrons, and electrons. The nucleus contains protons and neutrons, held together by the strong force, in which beta decay can take place as an effect of the weak force. The electrons are in a cloud outside the nucleus, held in place by electromagnetic forces but only allowed to occupy certain energy states by the rules of quantum physics. On large scales, gravity is important in holding bigger lumps of matter together.
* This gives us four particles (proton, neutron, electron, and neutrino plus their associated antiparticles) and four forces (electromagnetism, the strong and weak nuclear forces, and gravity. That is sufficient to explain everything that is detectable to our senses
* when two charged particles, such as two electrons, or an electron and proton, interact, they can be thought of as doing so by the exchange of photons. Two electrons, say, may move towards one another, exchange photons and be deflected on to new paths. It is this exchange of photons which produces the repulsion which shows up as an inverse square law, a law which emerges naturally from QED
* Protons and neutrons can be though of as composed on entities called quarks, held together by the exchange of entities analogous to photons, and that the strong nuclear force is just an outward manifestation of this deeper force at work.

== The Realm of Life ==
* We are the most complicated things that we know about in the entire universe. This is because, on the cosmic scale of things, we are middle-sized. Small objects, like atoms, are composed of a few simple entities obeying a few simple rules. The universe is so big that the subtleties of even objects as large as stars can be ignored, and the whole cosmos can be treated as a single object made up of a reasonably smooth distribution of mass-energy, again obeying a few very simple laws. But on the scales where atoms are able to join together to make molecules, the number of compounds possible - the number of different ways in which atoms can join together to make molecules - is so great that a huge variety of different things with complicated structures can exist and interact with one another in subtile ways.
* Life as we know it is a manifestation of this ability for atoms to form a complex variety of large molecules. This complexity starts on the next scale up from atoms, with simple molecules such as water and carbon dioxide; it ends where molecules begin to be crushed out of existence by gravity.
* Imagine starting out with a set of objects made up of 10 atoms, 100 atoms, 1000 atoms, and so on, with each lump containing ten times more atoms than the one before:
** The 24th object would be as big as a sugar cube
** The 27th - about the size of a large mammal
** The 39th - the size of a rock about a kilometer in diameter
** The 54th - the size of the planet Jupiter
** The 57th - about the size of the Sun, where even atoms are destroyed by gravity, leaving a mixture of nuclei and free electrons called a plasma.
* On this logarithmic scale, people are almost exactly halfway in size between atoms and stars. The realm of life forms like u,s investigated by Charles Darwin and his successors, is between the sizes of sugar lumps and large rocks
* The role of cells as the fundamental component of living things became clear at the end of the 1850s due to improving microscopic instruments and techniques.
* Matthias Shleiden (1804-1881), Theodor Schwann (1810-1882), John Goodsir (1814-1867), and Rudolf Virchow (1821-1902) developed the ideas of:
** All plant tissues are made of cells.
** All living things are made of cells.
** Cells arise only from other cells, by division.
** Every cell is derived from a preexisting cell and disease is no more than the response of a cell (or cells) to abnormal conditions, including tumors, which are derived from pre-existing cells in the the body;
* The microscopic techniques available at the time were more than adequate to show the structure of the cell as a bag of watery jelly with a central concentration of material, the nucleus.
* Walther Flemming (1843-1915) - discovered in 1879 that the nucleus contains thread-like structures which readily absorb colored dyes used by microscopists to stain cells and highlight their structure. These became known as chromosomes.
* August Weismann (1834-1914):
** Saw chromosomes as the carriers of hereditary information - « heredity is brought about by the transmission from one generation to another of a substance with a definite chemical and, above all, molecular constitution, »chromatin ».
** Spelled out two kinds of cell division:
*** For growth and development, all the chromosomes in a cell are duplicated before the cell divides, so each daughter cell obtains a copy of the original set of chromosomes
*** For production of egg or sperm cells, the amount of chromatin is halved, so that a full set of chromosomes is only restored when two such cells fused to create the potential for the development of a new individual.
** Showed that the cells responsible for reproduction are not involved with other processes going on in the body, and the cells that make up the rest of the body are not involved with the manufacture of reproductive cells, so that Darwin’s pangenesis and Lamarck’s ideas are both definitely wrong.
* In 1909, Wilhelm Johannsen, uses term « gene »
* William Bateson (1861-1926) - coined the term « genetics »
* Gregor Mendel (1822-1884) - Father of genetics
** In 1856, began an intensive study of the way heredity works in peas, working with 28, 000 plants, each pollinated by hand
** There is something in a plant that determines the properties of its overall form. These genes come in pairs, which can be the same, RR or SS, or different, RS. Only one of the genes in a pair, though, is expressed in the individual plant (the phenotype). If the R is ignored and the S expressed, then the S is said to be dominant and the R recessive.
** With this, Mendel showed that inheritance works not by blending characteristics, but by taking individual characteristics from each parent.
* Thomas Hunt Morgan (1866-1945)
** Wanted to disprove (or limit) Mendel’s findings
** Worked with Drosophila, fruit flies, where there is a new generation every two weeks, with each female laying hundreds of eggs at a time.
** Drosophila have only four pairs of chromosomes and one pair has a particular significance in all sexually reproducing species.
** Sex chromosomes are in one of two shapes, X and Y. Females always carry the XX pair, while males always have an XY combination.
** Different varieties of a particular gene are called alleles.
** Mendelian heredity and genetics came of age in 195, when he and his colleagues published « The Mechanism of Mendelian Heredity ».
** « The Theory of the Gene » (1926)
* The constant reshuffling of the genetic possibilities provided by the process of reproduction encourages diversity, which explains why it is so easy for sexually reproducing species to adapt to changing environmental conditions. Asexual species do evolve, but only much more slowly.
* In human beings, there are about 30k genes that determine the phenotype. Just over 93% are homozygous - the same on each chromosome of the relevant pair, in all human beings. Just under 7% are heterozygous, which means that there is a chance that there are different alleles for that particular gene on the paired chromosomes of an individual person chosen at random. With some 2000 pairs of genes which come in at least two varieties, no two people on Earth are genetically identical (except for twin who share the same genotype because they come from the same fertilized egg)
* Friedrich Miescher (1844-1895):
** Found that the composition of the nucleus was significantly different from that of protein. This substance, the nuclein, contains a lot of carbon, hydrogen, oxygen, and nitrogen, like other organic molecules, but he also found a significant amount of phosphorous, unlike any protein
** The sperm cell is almost all nucleus, with only a trace of cytoplasm.
* The building block which gives its name to DNA is ribose, a sugar whose central structure consistas of four carbon atoms linked with an oxygen atom in a pentagonal ring, with other atoms (notably hydrogen-oxygen pairs, OH) attached at the corners. These attachments can be replaced by other molecules, linking the ribose units to them
** The second building block, which attaches in this way, is a molecular group containing phosphorous, and is known as a phosphate group, acting as a link between ribose pentagons in an alternating chain.
** The third building block come in five varieties, called bases, known as guanine, adenine, cytosine, thymine, and uracil (G, A, C, T, and U); One base is attached to each of the sugar rings in the chain, sticking out at the side.
** The ribose pentagons gives the overall molecule its name, ribonucleic acid, or RNA
** DNA, Deoxyribonucleic acide is almost identical, with one less oxygen atom.
** RNA contains G, A, C, and U, while DNA contains G, A, C, and T.
** Covalent bonds - Carbon has six protons in its nucleus (and six neutrons, as it happens), plus six electrons in its cloud. Four bonds is the maximum any atom can make, and bonds are stronger for shells closer to the central nucleus
** Ionic bonds
** There is no arbitrariness in the arrangement of electrons in atoms and atoms in molecules - the arrangements which are most stable in the atoms and molecules are always the arrangements with the least energy.
* X-rays are a form of electromagnetic wave, like light but with shorter wavelengths
* In a substance like sodium chloride there are no individual molecules (NaCl), but an array of sodium ions and chlorine ions arranged in a geometric pattern.
* The structure of biomolecules, such as haemoglobin, insulin, and the muscle protein, myoglobin
* Hydrogen bonds - unlike all other chemically reactive atoms (helium is not chemically reactive), hydrogen has no other electrons in inner shells to help conceal the positive charge on its proton, so some of the positive charge is « visible » to any nearby atoms or molecules. This will attract any nearby atom which has a preponderance of negative charge - such as an oxygen atom in a water molecule, which has gained extra negative charge from its two hydrogen atoms.
* Astbury showed that globular protein molecules (such as haemoglobin and myoglobin) are made up of long-chain proteins (polypeptide chains) that are folded up to make balls.
* Pauling laid out in detail the chemical structure of hair, feathers, muscles, silk, horn, and other protein, as well as the alpha-helix structure, as it became known, of the fibres themselves.
* James Watson (1928-) and Francis Crick (1916-) where influenced by Schrôdinger’s « What is Life? » (1944), which noted that in a code similar to the Morse code but with three symbols, not just dot and dash, used in groups of ten, you could form 88,572 different « letters ».
* Griffith worked out from the shapes of the molecules that adenine and thymine could fit together, linking up through a pair of hydrogen bonds, while guanine and cytosine could also fit together, linking up through a set of three hydrogen bonds, but that the four bases could not pair up in any other way.
* The structure of DNA must involve pairs of long-chain molecules, linked together by AG and CT bridges
* The genetic code is actually written in triplets, with sets of three bases, such as CTA or GGC, representing each of the twenty or so individual amino acids used in the proteins that build and run the body. When proteins are being manufactured by the cell, the relevant part of the DNA helix containing the appropriate gene uncoils, and a string of three-letter codons is copied into a strand of RNA (which of RNA and DNA was first?); this messenger RNA, whose only essential difference to DNA is that it has uracil everywhere DNA has thymine, is then used as a template to assemble a string of amino acids corresponding to the codons, which are linked together to make the required protein. It keeps doing this until no more of that particular protein is required. The DNA has long since coiled up again, and after enough protein has been manufactured the RNA is disassembled and its components reused. Just how the cell knows when and where to do all this remains to be explained, but the principles of the process were clear by the mid 1960s
* During all the copying of DNA that goes on when cells divide, there must occasionally be mistakes. Bits of DNA get copied twice, or bits get left out, or one base (one letter in the genetic code) gets accidentally replaced by another. None of this matters much in the kind of cell division that produces growth, since all that happens is that a bit of DNA in a single cell (probably not even a bit of DNA that that particular cell uses) has been changed. But when reproductive cells are produced by the special process of division that halves the amount of DNA in the daughter cells, not only is there more scope for mistakes to occur.
* By the late 1990s, it had been established that human being share 98.4% of their genetic material with the chimpanzee and the gorilla making us, in popular terminology, only « 1% human »
* The human, chimp, and gorilla lines split from a common stock just 4m ya.
* Human beings have only about 30k genes, which are capable of making at least 250k proteins. This is only twice as many genes as the fruit fly, and just 4k more than a garden weed called thale cress. A few key genes are different in us, compared with our closest relatives, and these are affecting the way the other genes operate.
== Outer Space ==
* Units:
** au (Astronomical Unit) - approx 150m km - for distances within the Solar System - average distance between the Earth and the Sun
*** Earth is 1 au from the Sun (149.6m km).
*** Mars is 1.5 au from the Sun
*** Jupiter is 5.2 au from the Sun
*** Neptune is 30 au from the Sun
*** Sirius is 550 au, or 2.67 pc, away.
** ly (Light Year) - approx 9460b km or 63,240 au - the distance light travels in a vacuum in a year
*** Speed of light - 300,000km/s
*** The Milky Way is 75,000 ly (34kpc) in diameter
*** The Andromeda Galaxy is more than 2.5m ly (780 kpc) from Earth (closest galaxy to us)
*** Proxima Centauri is 4.22 ly (1.3 pc) from Earth (closest star to the Sun)
*** Sirius is 2.67 pc from us, and is brighter than the Sun
*** 61 Cygni is 11.2 ly or 3.4 pc away.
*** Orion Nebula is 1501 ly from Earth
** Parsec (pc) - 3.26 ly (206,265 au, 30.9t km). Also kiloparsec (kpc), megaparsec (Mpc), gigaparsec (Gpc)
*** The center of the Milky Way is more than 8kpc from the Earth
*** The nearest large galaxy cluster, the Virgo Cluster is about 16.5Mpc from the Earth
*** The galaxy RXJ1242-11, with a supermassive black hole core similar to the Milky Way’s is about 200Mpc from the Earth
*** The particle horizon (the boundary of the observable universe has a radius of approx 14Gpc
* Our understanding of the universe at large rests upon two foundations - being able to measure the distances to the stars, and being able to measure the compositions of the stars.
* The Moon, our nearest neighbor, is just 384,400km away
* The Sun is 149.6m km away.
* By the end of the 18th C, astronomers had a very good idea of the scale of the Solar System.
* Parallax effect - hold a finger out at arm’s length and close each of your eyes in turn, the position of the finger seems to move against the background of more distant objects.
* Astronomers define one parallax second of arc, or parsec, as the distance to a star which would show a displacement of one second of are on the sky from opposite ends of a baseline 1 AU (150m km) long.
* The brightness of an object is inversely proportional to the square of its distance.
* The nearest star to the Sun is 7000 times further away than Pluto
* By 1950, the distances to some 10,000 stars had been determined, and by 2000, some 120,000 stars had been measured.
* Modern astronomy, astrophysics, only began at the beginning of the 20th C because of the application of photographic techniques to preserve images of the stars
* The masses of stars
* The Doppler effect - produces a redshift, with the size of the shift indicating the relative speed of he object.
* Keppler’s laws
* The Hertzsprung- Russell diagram (HR or color-magnitude diagram) is as important to astronomy as the table of elements is to chemistry:
** Developed by Ejnar Hertzsprung (1873-) and Henry Norris Russell (1877-).
** The temperature of a star is closely related to its color.
** Blue and white stars are always intrinsically bright, while some orange and red stars are bright and some are faint.
** The color, precisely defined, can tell you the temperature of the surface emitting the light.
** The intrisic brightness of a star (its absolute magnitude), tells you how much energy the star is radiating overall, regardless of its temperature.
** Most stars lie on a band running diagonally across the diagram, with hot, massive stars about the same size (diameter) as the Sun at one end of the band, and cool, dim stars with less mass than the Sun at the other end.
** The Sun itself is an average star, roughly in the middle of this so-called main sequence.
** Red giants - large, cool but bright stars, lie above the main sequence
** White dwarfs - small but hot stars, lie below the main sequence
* Arthur Eddington (1882-):
** The first astrophysicist, popularized Einstein’s theories of relativity in English - « the man who proved Einstein was right »
** With the data from the HR diagram, showed that the brighter stars are the most massive. A main sequence star 25x the mass of the Sun, for example, is 4000x as bright as the Sun. A star holds itself up by the pressure it generates in its interior, counteracting the inward pull of gravity. The more massive it is, the more weight there is pressing inwards and the more pressure it has to generate. It can only do this by burning its fuel mor quickly, thereby generating more heat, which eventually escapes from the surface of the star as more light for us to see.
** The temperature at the heart of a star can be calculated from observations of its brightness, mass and size
** Eddington discovered that all main sequence stars have roughly the same central temperature, even though they cover a range in masses from tens of times the mass of the Sun down to a tenth the mass of the Sun. It seems as if stars have an inbuilt thermostat; as a ball of gas shrinks under its own weight and gets hotter inside as gravitational energy is converted into heat, nothing happens to halt this process until a critical temperature is reached, when the thermostat switches on an almost inexhaustible supply of energy.
** It was clear that « subatomic » energy must hold the key to the longevity of the Sun and stars: « If 5% of a star’s mass consists initially of hydrogen atoms, which are gradually being combined to form more complex elements, the total heat liberated will more than suffice for our demands, and we need look no further for the source of a star’s energy.
* The Mily Way is nothing special in the Universe.
* One class of pulsating stars, the Cepheids, all show a characteristic pattern of repeated brightening and dimming, but some have periods as short as a day or so, while others have periods of more than a hundred days.
* The Large and Small Magellanic Clouds are now known to be small satellite galaxies associated with the Milky Way. Hertzsprung’s calibration implied a distance to the Small Magellanic Clouds (SMC) of 30,000 ly (approx 10 kpc) - now we see these, taking account of reddening and extinction effects, as 170,000 ly (52 kpc)
* George Ellery Hale (1868-1938)
** Organized the construction of the 100-inch Hooker telescope, completed on Mount Wilson in 1918 and still in use today. It was the largest telescope of Earth for 30 years
* Edwin Hubble (1889-1953) and Milton Humason (1891-1972)
* The band of light on the night sky known as the Milky Way is a flattened, disc-shapes system containing vast numbers of stars, and the Sun is just one star among this multitude.** The Sun is not at the center of the Milky Way
* Exploding stars, supernovae, all have roughly the same absolute maximum brightness.
* There are hundreds of billions of galaxies in the visible Universe, which extends for billions of light years in all directions.
* Our galaxy is just average in size.
* There is a relationship between the distance to a galaxy and the redshift in the redshift in the spectrum of light from it.
* Einstein’s great insight was to appreciate that there is no distinction between acceleration and gravity.
* Bernhard Reimann (1826-1866) developed the mathematical tools to describe non-Euclidean geometry of curved surfaces, following on from the work of Karl Friedrich Gauss (1777-1855).
** In non-Euclidean geometry, parallel lines can cross one another
** Found a general mathematical treatment which was the footing for the whole of geometry, allowing a range of different mathematical descriptions of a range of different geometries, which are all equally valid and with the familiar Euclidean geometry of everyday life as just one example
** The best way to describe the Universe at large is in terms of curved space.
** Concentrations of matter, such as the Sun, are now seen as making little dimples in the spacetime of an otherwise flat Universe.
* The general theory of relativity describes the relationship between spacetime and matter, with gravity as the interaction that links the two. The presence of matter bends spacetime, and the way material objects (or even light) follow the bends in spacetime is what shows up to us as gravity: « Matter tells spacetime how to bend; spacetime tells matter how to move ».
* The equations that Einstein found had one bizarre and unexpected feature. In their original form, they did not allow for the possibility of a static universe. The equations insisted that space itself must either be stretching as time passed, or shrinking, but could not stand still. So he added another term, using the Greek letter lambda (λ) - the cosmological constant.
* You can choose different values for lambda, some of which would make the universe expand faster, at least one of which would hold it still, and some of which would make it shrink.
* The cosmological redshift is not caused by galaxies moving through space, and is not, therefore, a Doppler effect. It is cause by the space between the galaxies stretching as time passes, exactly in the way that Einstein’s equations described, but Einstein refused to believe, in 1917. If space stretches while light is en route to us from another galaxy, then the light itself will be stretched to longer wavelengths, which, for visible light, means moving it towards the red end of the spectrum. The existence of the observed redshift-distance relation (Hubble’s law) implies that the Universe was smaller in the past, not in the sense that galaxies were crammed together in a lump in a sea of empty space, but because there was not space either between the galaxies or “outside” them - there was no outside. This in turn implies a beginning to the Universe - the Big Bang model.
* The steady state model sees the Universe as eternal, always expanding, but always looking much the same as it does today because new matter, in the form of atoms of hydrogen, is continuously being created in the gaps left behind as galaxies move apart , at just the right rate to make new galaxies to fill the gaps. This was a sensible and viable alternative to the Big Band model right through the 1950s and into the 1960s - it is, after all, no more surprising that matter should be created steadily, one atom at a time, than it is to suggest that all the atoms in the Universe were created in one event, the Big Bang. But improving observations, including the new techniques of radio astronomy developed in the 2nd half of the 20th C, showed that galaxies far away across the Universe, which we see by light (or radio waves) which left them long ago, are different from nearby galaxies, proving that the Universe is changing as time passes and galaxies age.
* By the end of the 20th C the age of the Universe had been determined reasonably accurately as somewhere between 13bn and 16bn years. This is calculated from the general theory of relativity and deals with the laws of physics on the very large scale. The ages of stars are essentially calculated from the laws of quantum mechanics, physics on the very small scale. The ages of the Universe comes out to be just enough older than the ages of the oldest stars to allow the time required for the first stars to form after the Big Bang. Thus are agree physics on both the largest and smallest scales.
* The chemical elements we, and the rest of the visible Universe are made of have to come from somewhere, and Gamow guessed that the raw material for their manufacture was a hot fireball of neutrons.
* Although the raw material was assumed to be neutrons, neutrons themselves decay in this way to produce electrons and protons, which together make the first element, hydrogen. Adding a neutron to a hydrogen nucleus gives a nucleus of deuterium (heavy hydrogen), adding a further proton makes helium-3, and adding another neutron as well makes helium-4, which can also be made by the fusion of two helium-3 nuclei and the ejection of two protons, and so on. Nearly all the deuterium and helium-3 is converted into helium-4, one way or another. Alpher and Gamow looked at all of the available neutron-capture date for different elements and found that the nuclei formed most easily in this way turned out to be those of the most common elements, while nuclei that did not form readily in this way corresponded to rare elements.
* 1 April 1948 marks the beginning of Big Band cosmology as a quantitative science with the publication of the Alpher, Bethe, Gamow (alpha-beta-gamma) paper
* The cosmic microwave background radiation is the most powerful single piece of evidence that there really was a Big Bang, that the visible Universe experienced an extremely hot, dense phase about 13bn ya
* If you can only make hydrogen and helium (and tiny traces of lithium-7 and deuterium) in the Big Bang, then all the other elements must have been manufactured somewhere else. The somewhere is the inside of stars. In the 1920s and 1930s, we began to realize that the Sun and stars are not made of the same mixture of elements as the Earth.
* The composition of stellar atmospheres is dominated by hydrogen. There are a million times more hydrogen atoms present in the atmosphere of stars than there are atoms of everything else put together. Heavy elements are rare in stars and hydrogen and helium make up 99% of star stuff.
* Hans Bethe and Carl von Weizsäcker identified two processes:
** The proton-proton chain
** The carbon cycle, operates in a loop and requires the presence of a few nuclei of carbon, involvin protons tunnelling into these nuclei. Because it is a loop, these heavy nuclei emerge at the end of the cycle unchanged, effectively acting as catalysts. It outputs an alpha particle (a nucleus of helium-4 - the net effect is that four protons have been convered into a single nucleus of helium, with a couple of positrons and a lot of energy ejected along the way.
* Once you have carbon nuclei to work with, you can make heavier elements still by adding more alpha particles (going from carbon-12 to oxygen-16 to neon-20 and so on.
* The definitive account of how the elements are built up in this way inside stars is given in a paper in 1957 by BBFH, and this understanding of nuclear fusion processes inside stars explained how all the elements up to iron can be manufactured from hydrogen and helium. Even better, the proportions of the elements predicted to be produced match the proportions seen in the Universe at large.
* But it cannot explain the existence of elements heavier than iron, because iron nuclei represent the most stable form of everyday matter with the least energy. To make nuclei of even heavier elements - such as gold, uranium, or lead - energy has to be put in to force the nuclei to fuse together. This happens when stars rather more massive than the Sun reach the end of their lives and run out of nuclear fuel which can generate heat to hold them up. When their fuel runs out, such stars collapse dramatically in upon themselves and as they do so, enormous amounts of gravitational energy are released and converted into heat. One effect of this is to make the single star shine, for a few weeks, as brightly as a whole galaxy of ordinary stars, as it becomes a supernova; another is to provide the energy which fuses nuclei together to make the heaviest elements. And a third effect is to power a huge explosion in which most of the material of the star, including those heavy elements, is scattered through interstellar space, to form part of the raw material of new stars, planets and possibly people.
* In 1987, a supernova was seen to explode in our near neighbor, the Large Magellanic Cloud
* Apart from helium, which is an inert gas that does not take part in chemical reactions, the four most common elements in the Universe are hydrogen, carbon, oxygen and nitrogen, collectively known as CHON
* There is no evidence of a special life force, and all of life on Earth, including us, is based on chemical processes. And the four most common elements involved in the chemistry of life are hydrogen, carbon, oxygen and nitrogen. We are made out of exactly the raw materials which are most easily available in the Universe. Earth is not a special place, and life forms based on CHON are likely to be found across the Universe, not just in our Galaxy but in others.
* Four and a half centuries after the publication of De Revolutionibus, we are in the situation a that small child who has just learned the rules of the game. We are just beginning to make our first attempts to play the game, with developments such as genetic engineering and artificial intelligence.