Saturday, January 9, 2010

Gerald Edelman: Wider than the Sky

G. Edelman (2004) Wider than the Sky - The Phenomenal Gift of Consciousness (Yale University Press)
Google Books

This is probably one of the most important books that I have read in the last few years. It is an easy read and very thought-provoking. Highly recommended.

This is a synopsis and some notes and quotes from 'Wider than the Sky'.
Edelman's work on both researching and describing neuroanatomy has significantly changed the way we see how the brain works. It is not too difficult to follow and should be enough to rock subjects like psychology to the core as they seem happy to proceed on the delusion that there is some kind of metaphysical (i.e. non-physical) mind that bears no resemblance to the brain. With people such as Edelman and Maturana and Varela on the case, metaphysical approaches to the mind should soon be a thing of the past (wishful thinking!!)

Re-entry within the dynamic core of the brain allows for primary consciousness: mediation of value-category memory (originating in bodily experiences, and thru re-entry can be re-enacted with or without motor function at any time) and perceptual categorisation (the here and now of sorting perception into different objects).
Higher-Order consciousness = re-entrant circuits mediating between primary consciousness and semantic capability. Symbolic nature of semantic dissociation between symbol and meaning combined with the flexibility of manipulating these symbols thru syntax releases the consciousness from the “remembered present” and thru these re-entrant circuits enables remembered past, imagined past and future, and planned future.

“although the conscious process involves representation, the neural substrate of consciousness is non-representational” (104)

“mental images arise in a primary-consciousness scene largely by the same neural processes by which direct perceptual images arise. One relies on memory, the other on signals from without.” (105)
[it is thru re-entry that these processes are so similar]

This view rejects the notion of computation and the idea that there is a “language of thought.” Meaning is not identical to mental representation. Instead it arises as a result of the play between value systems, varying environmental cues, learning, and non-representational memory. (105)
[also Thibault Jnl of Prag.]

“…much of cognitive psychology is ill-founded. There are no functional states that can be uniquely equated with defined or coded computational states in individual brains and no process that can be equated with the execution of algorithms. Instead, there is an enormously rich set of selectional repertoires of neuronal groups whose degenerate responses can, by selection, accommodate the open-ended richness of environmental input, individual history and individual variation. Intentionality and will, in this view, both depend on local contexts in the environment, the body and the brain, but they can selectively arise only through such interactions and not as precisely defined computations.” (111)
[embodied and grounded!!]

Constructivist brain:
“Filling in of the blind spot, the phenomena of apparent motion, and gestalt phenomena can all be explained in terms of temporal synchrony in re-entrant circuits. The same is true of time, of succession and of duration. The re-entrant brain combines concepts and percepts with memory and new input to make a coherent picture at all costs.” (124)
e.g. saccades: eye movements are erratic, with the eye ‘jumping’ to a new point of focus, often as a result of peripheral vision, and then resting. Our experience of vision, however, is one of a smooth transition from one scene to the next.

”Given the continual sensorimotor signals arising from the body, subjectivity is a baseline event that is never extinguished in the normal life of conscious individuals. But there is no need for an inner observer or a “central I” – in James’s words, “the thoughts themselves are the thinker”.” (134)

Higher order consciousness may be considered as a trade-off of absolute precision for rich imaginative possibilities. (135)

The pervasive presence of degeneracy in biological systems is particularly noticeable in neural systems, and it exists to a high degree in the rentrant selective circuits of the conscious brain. In certain circumstances, natural languages gain as much strength from ambiguity as they do under other circumstances through the power of logical definition. Association and metaphor are powerful accompaniments of (135) conscious experience even at early stages, and they flower withy linguistic experience. (136)

…the study of consciousness must recognize the first-person, or subjective, point of view. (140)

Consciousness is a property of neural processes and cannot itself act causally in the world. (141)

Whether in the dreams of REM sleep, or in imagery, or even in perceptual categorization, a variety of sensory, motor, and higher-order conceptual processes are constantly in play… in visual imagery, the same reentrant circuits used in direct perception are reengaged but without the more precise constraints of signals from without. In REM sleep, the brain truly speaks to itself in a special conscious state – one constrained neither by outside sensory input nor by the tasks of motor output. (144)

I also posted this on my pages.

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