(Reconciling the Mysterians and the Reductionists in Conceptions about consciousness.)

In reporting on the Consciousness Conference at the University of Arizona (“Wow, it’s just like Woodstock”, one attender exclaimed), John Horgens (“Can Science Explain Consciousness”, article in “The Scientific Book on the Brain”, pp. 297-309) distinguishes two types of scientists: the “mysterians” who say that consciousness can never be explained from physical principles or neuron circuits in the brain, and the reductionists, who hope to explain consciousness precisely in that way. David Chalmers represents the mysterians: he says that it is easy to explain some neural correlates of consciousness, but the “hard problem” (how this gives rise to subjective experience) remains unsolved. Francis Crick represents the reductionists, along with his colleague Christof Koch. Chalmers and Koch met and argued at this conference, without resolving their differences. However, I would like to try. (Both Chalmers and Crick have articles in this book in the same section as Horgens.)

Chalmers claims that the new field of consciousness research, also called psychophysics (I have used that term too in a previous essay, claiming that it represents the fifth branching off from standard Newtonian physics (in addition to relativity theory, quantum theory, thermodynamics, and complexity theory) needs a new basic concept, as standard physics once did in its beginning. To my delight, he thinks that the new bridging concept between physics and consciousness is information, which happens to be the “third essence” in my “three (or four) essences” theory.

Information, Chalmers claims, comes in two varieties: physical (as described by Claude Shannon in his information theory as the opposite of entropy, a concept in thermodynamics), and mental, represented in the brain by sense data transcribed into neuronal firing patterns. What the two types of information have in common, in my opinion, is the presence of structure, a map of interactions. Structure does not depend on the substrate, i.e. the nodes or entities being interconnected or linked: e.g. a painter can work in oil paints or water colours or other media to represent a structure, a sculptor can use marble or bronze or whatever.

Therefore, it seems to me, physical structure in the outside world (its information content) can be directly translated into the same structure in the medium of neuronal circuits. Thus we gain an accurate knowledge of objects in the external world; not of their matter or energy, which are “things in themselves” beyond our grasp, but of the informational structure. The shadows on the walls of Plato’s cave are written in the language of information.

However, the mind adds MEANING to this “mere information”: e.g. “this object is good to eat, that one is poisonous”, “this animal threatens me, that one is harmless, the third is my own offspring, the fourth is a friend, the fifth I can kill and eat”. This kind of meaning plus the incoming information is essential for survival, for the satisfaction of needs, for seeking pleasure, and for avoiding pain.

Now Crick too, on p. 313 in the book, says that the brain carries out complex computations to interpret an ambiguous visual signal. This implies, according to Crick, “that the brain forms a symbolic representation of the visual world, with a mapping (in the mathematical sense) of certain aspects of that world into elements in the brain.” It seems to me that this is in agreement with what Chalmers is saying.

Crick also states, as William James originally said, that conscious action requires not only awareness and interpretation of sense information, but also attention (focusing the searchlight in the “room of the mind” on the information), and short-term memory (classified as either iconic memory lasting only a fraction of a second, or working memory which lasts for a few seconds, or longer if rehearsed). Also, the hippocampal system can slowly pass episodic memories into long-term memories. Note, as described in another essay (“Long-Term Potentiation”), that memories of all kinds are represented in the brain by a pattern (structure) of more or less strengthened or weakened Hebbian junctions between neurons.

Earlier I mentioned that introspection might be a method for exploring psychophysics. I no longer think so, because conscious introspection does not penetrate into the deep unconscious, where most mental events (by far) happen. Perhaps in the meditation state introspection can reach farther, but that is by no means established.