Friday, June 10, 2016

Explaining Consciousness

Fernando mentioned that as a child he used to think of himself as residing behind his eyes and issuing commands to his body. I think most of imagine our consciousness in a somewhat similar fashion - a sort of ghost in the machine, getting input from its senses and and issuing commands to its limbs. If we want to imagine a purely physical implementation, though, we seem faced by a kind of circularity. The nerves of the eye seem to project to a sort of television set in the head, or rather to several of them, which invites the question: Who watches it, and how? Many of our questions about consciousness bring in this sort of puzzle.

Descartes imagined a an independent watcher, a soul or a ghost in the machine, but neuroscience wants a more mechanical solution. The Cartesian solution, after all, just transfers the problem to some imagined astral plane.

If I understand correctly, it is puzzles of this sort that motivate the criticisms of Lee, WB and other clever people. I fear that one elderly, not very smart retired physicist will not solve them, but I do think that there is a solution, or at least an approach to a solution, that some clever people have propounded. Two books on the general topic are Consciousness Explained by Daniel Dennett ($0.44 via Amazon) and The Society of Mind by Marvin Minsky.

Imagine a very smart television that could interpret the images it displays. Those images are automatically classified and compared with others in its various data bases, and something like a narrative summary of the highlights is prepared. That seems to be one of the functions of consciousness in humans. Another is keeping track of the self and its relationships to the non-self in the environment.

We have the impression that consciousness and the self are unitary and indivisible, but neurobiology says otherwise, for example in the case of the split brain patients.

Of course these paragraphs aren't pretending to be an explanation consciousness. Dennett's book runs to 500 and some pages, and I doubt that anyone would consider it definitive. Some, of course, denounce it.

Pinker:

We have every reason to believe that consciousness and decision making arise from the electrochemical activity of neural networks in the brain. But how moving molecules should throw off subjective feelings (as opposed to mere intelligent computations) and how they bring about choices that we freely make (as opposed to behavior that is caused) remain deep enigmas to our Pleistocene psyches.

These puzzles have an infuriatingly holistic quality to them. Consciousness and free will seem to suffuse the neurobiological phenomena at every level, and cannot be pinpointed to any combination or interaction among parts. The best analyses from our combinatorial intellects provide no hooks on which we can hang these strange entities, and thinkers seem condemned either to denying their existence or to wallowing in mysticism. For better or worse, our world might always contain a wisp of mystery, and our descendants might endlessly ponder the age-old conundrums of religion and philosophy, which ultimately hinge on concepts of matter and mind. 61

Ambrose Bierce’s The Devil’s Dictionary contains the following entry:

Mind, n. A mysterious form of matter secreted by the brain. Its chief activity consists in the endeavor to ascertain its own nature, the futility of the attempt being due to the fact that it has nothing but itself to know itself with.

Pinker, Steven. The Blank Slate: The Modern Denial of Human Nature (p. 240). Penguin Publishing Group. Kindle Edition.