1. The Stuff of Dreams
- Two puzzles that have bedevilled thinkers for centuries:
- The mind/body problem - How the mind relates to the body, or how the brain gives rise to the mind.
- The problem of other minds - What can we tell about what happens in other people's minds.
- In the first half of the 20th C, behaviorism worked with classical conditioning and operant conditioning (the Law of Effect)
- In the second half, behavorism was gradually eclipsed by "cognitive" psychology, which formulates models of the information processing that goes on within minds. It suggests that the mind is a function rather than a structure. The software of the mind is implemented by the hardware of the brain and could be implemented elsewhere. Both brains and computers perform:
- Memory functions (they encode and store information)
- Perceptual functions (they classify patterns of incoming information by comparing them with stored information)
- Executive functions (they execute decisions about what to do in response to such information)
- In parallel with cognitive psychology developed "cognitive neuroscience", which focuses on the hardware of the mind.
- Paradoxical sleep, where the brain is physiologically aroused despite being fast asleep.
- The whole sleep/waking cycle - including REM sleep and dreams as well as the different stages of non-REM sleep - is orchestrated by a small number of brainstem nuclei interacting with each other.
2. Before and After Freud
- Freud argued that the erratic train of our conscious thoughts can be explained only if we assume implicit intervening links of which we are unaware. This gave rise to the notion of latent mental functions and, in turn, to Freud's famous conjecture of "unconscious" intentionality.
- He concluded that what ultimately underpinned feelings were bodily needs; that human mental life, no less that that of animals, was driven by the biological imperatives to survive and reproduce. These imperatives, for Freud, provided the link between the feeling mind and the physical body.
- Freud wanted to find metapsychological functional laws. Trying to skip over the functional level of analysis, jumping directly from psychology to physiology, is nowadays called the localisationist fallacy.
- Freud's "project" spoke of the forebrain as a sympathetic ganglion monitoring and regulating the needs of the body and of these needs as the driving force of mental life, "the mainspring of the psychical mechanism":
- Drive - the psychical representative of the stimuli originating from within the organism and reaching the mind, as a measure of the demand made upon the mind for work in consequence of its connection with the body. He described the causal mechanisms by which drives become intentional cognition as an "economics of nerve-force".
- "The Id, cut off from the external world, has a world of perception of its own. It detects with extraordinary acuteness certain changes in its interior, especially oscillations in the tension of its drive needs, and these changes become conscious as feelings in the pleasure-unpleasure series. It is hard to say, to be sure, by what means and with the help of what sensory terminal organs these perceptions come about. But it is an established fact that self-perceptions - coenaesthetic feelings and feelings of pleasure-unpleasure - govern the passage of events in the id with despotic force. The id obeys the inexorable pleasure principle."
- "What consciousness yields consists essentially of perceptions of excitations coming from the external world and of feelings of pleasure and unpleasure which can only arise from within the mental apparatus; it is therefore possible to assign to the system Pcpt-Consciousness a position in space. It must lie on the borderline between inside and outside; it must be turned towards the external world and must envelop the other psychical systems.
- For Freud, clearly, conscious feelings, no less than perceptions, are generated in the "ego" (the part of the mind that he identified with the cortex), not in the unconscious "id" - which I was now obliged to locate in the brainstem and hypothalmus. In short, it seemed that Freud got the functional relationship between the "id" (brainstem) and the "ego" (cortex) the wrong way round, at least insofar as feelings are concerned. He thought the perceiving ego was conscious and the feeling id was unconscious. Could he have got his model of the mind upside down?
3. The Cortical Fallacy
- Hydranencephalic children are born without a cortex.
- Decorticated mammals exhibit a remarkable persistence of coherent, goal-oriented behavior that is consistent with feelings and consciousness. In many respects, decorticate mammals are in fact more active, emotional and responsive than normal ones.
- Information from the sense organs is fed not only to the cortex but also to the superior colliculi of the brainstem, via a set of subcortical connections.
- Two principal meanings of the term consciousness:
- Consciousness as the waking state - A necessary condition for consciousness in the second sense
- Consciousness as experience
- The way in which ideas become conscious in response to an external stimulus was called apperception (which roughly means perceiving the present through the lens of past experience).
- Meynert in 1884 identified the mind with the totality of memory images of objects produced by projection of the sensory-motor periphery onto the cortex plus transcortical associations between them and those memory images that constituted abstract ideas.
- Penfield and Jasper concluded that cortical resections do not interrupt sentient being; they merely deprive patients of certain forms of information.
4. What is Experienced?
- The scientific evidence showing that we are unaware of most of what we perceive and learn is now overwhelming. Perception and memory are not inherently conscious brain functions.
- If the cortex is not connected directly with the body periphery, but rather via intermediate subcortical links, then the memory images deposited in the cortex cannot be literal projections of the world outside. They must be the end products of multi-stage information processing.
- It makes no sense, Freud argued, to draw an artificial line between the subcortical and cortical parts of the processing and claim that only the final product is "mental".
- Freud concluded that both conscious and unconscious memory images are formed in sympathy with the demands of the body - that we only perceptually represent and learn about the outside world because we must meet our biological needs there.
- Patients and research participants are conscious of their feelings; they are unconscious only of where the feelings came from. Apparently alone among mental functions, feeling is necessarily conscious.
- What turns up in consciousness? "Representations" of the outside world and feelings:
- About what is going on in the world, about our thoughts about that world, about ourselves, including feelings that seem to be reports on the conditions of our bodies.
- Free-floating feelings, the emotions and moods that qualify our experience of the world and shape our behavior within it. Sometimes they register as bodily sensations; still, many moods seem attributable neither to the condition of our bodies not to anything we can put our fingers on in the world outside. Isn't consciousness full of feelings like this? And yet, to an amazing degree, neuroscientists searching for an explanation of consciousness have ignored them.
- Feeding behavior is regulated by two interacting brain mechanisms: a "homeostatic" system, which regulates energy stores, and a "hedonic" system, which mediates appetite. And just as with bodily affects like hunger, might not the prohibition of emotional words like "sadness" and "fear" delay the development of antidepressant and anti-anxiety treatments?
- Feelings are real, and we know about them because they permeate our consciousness. They are, in fact, for the reasons I will now explain, the wellspring of sentient being - in a sense that seems to me barely metaphorical. From their origin in some of the most ancient strata of the brain, they irrigate the dead soil of unconscious representations and bring them to mental life
5. Feelings
6. The Source
7. The Free Energy Principle
8. A Predictive Hierarchy
9. Why and How Consciousness Arises
10. Back to the Cortex
11. The Hard Problem
12. Making a Mind
