Brain - Revision history

Rob: /* Brain Parts */

2025-04-21T10:03:01Z

Brain Parts

← Older revision		Revision as of 10:03, 21 April 2025
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	[[Evolution of the Brain]]		[[Evolution of the Brain]]

	== Brain ~~Parts~~ ==		== Brain Components ==
			Three main regions based on location:
	* [[~~Hypothalamus~~]]		* The Forebrain (Prosencephalon) - Front and upper regions, responsible for higher-level functions
	* [[~~Thalamus~~]]		** Cerebrum - Two hemispheres, each covered by the cerebral cortex, which is responsible for complex cognitive functions. Separated into four lobes from front to back:
	* [[~~Cerebellum~~]] - ~~major~~ role in motor control. ~~May also be involved~~ in ~~cognitive~~ functions, ~~such as attention~~ and ~~language as well as emotional control~~		*** 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		* [[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

193.16.224.14 at 17:36, 16 February 2025

2025-02-16T17:36:02Z

← Older revision		Revision as of 17:36, 16 February 2025
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	** Instrumental learning - allowing rewards and punishments to modify behavior		** Instrumental learning - allowing rewards and punishments to modify behavior
	** Motor learning - refining patterns of body movement by practicing or repetition		** Motor learning - refining patterns of body movement by practicing or repetition

			[[Category:Consciousness]]

Rob: /* Evolution of the Brain */

2025-01-26T17:27:04Z

Evolution of the Brain

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 == Evolution of the Brain ==
-===600m ya - Bilaterians and Steering  ===
+[[Evolution of the Brain]]
 == Brain Parts ==

2A01:CB00:4CA:C200:10:C3E1:2986:B6D3 at 17:25, 26 January 2025

2025-01-26T17:25:40Z

← Older revision		Revision as of 17:25, 26 January 2025
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	== Evolution of the Brain ==		== Evolution of the Brain ==
	=== Valence ===		===600m ya - Bilaterians and Steering ===

			==== Valence ====

	* Bilaterians are the only animals that have brains		* 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.		* Nematodes (legless wormlike creatures about the size of a grain of rice) emerge in the Edicaran period from 635 to 539m ya.
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	* 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.		* 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 ===		==== Emotions ====

	* Affect is the name for the unifying foundation of emotions		* Affect is the name for the unifying foundation of emotions
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	** Do I want to expend energy by moving?		** Do I want to expend energy by moving?
	** Do I want to stay here or leave?		** 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

Rob at 12:02, 26 January 2025

2025-01-26T12:02:56Z

← Older revision	Revision as of 12:02, 26 January 2025
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		== Evolution of the Brain ==
		=== 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?

Rob at 10:48, 14 April 2024

2024-04-14T10:48:42Z

← Older revision		Revision as of 10:48, 14 April 2024
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	** Hippocampus - involved with aspects of memory storage		** Hippocampus - involved with aspects of memory storage
	** Amygdala - coordinates autonomic and endocrine responses in the context of emotional states		** 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

Rob: Created page with " == Brain Parts == * Hypothalamus * Thalamus * Cerebellum - major role in motor control. May also be involved in cognitive functions, such as attention and language as well as emotional control * 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 ** Fr..."

2024-04-14T10:21:39Z

Created page with " == Brain Parts == * Hypothalamus * Thalamus * Cerebellum - major role in motor control. May also be involved in cognitive functions, such as attention and language as well as emotional control * 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 ** Fr..."

New page

== Brain Parts ==

* [[Hypothalamus]]
* [[Thalamus]]
* [[Cerebellum]] - major role in motor control. May also be involved in cognitive functions, such as attention and language as well as emotional control

* [[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