Tuesday, December 26, 2006

My perception is a part of me.

Although it surely fits the common sense, it is misleading to say that "I" perceive something that is "outside" me. From the point of the evolution of biological systems, it is fair to say that the function of the brain is first and foremost the reconstruction of the outside world so that one could catch food and avoid enemies, as argued by David Marr and others. From the phenomenological point of view, however, "my perception is part of me", as long as all that I consciously perceive depend on the activities of neurons in the brain alone. It may even be argued that in principle, what I perceive in my consciousness and what I get from outside as physical stimuli can be unrelated. The phenomenological qualities that are invoked in a subject's consciousness depends on, and are generated by, the neural firing in the subject's brain only, no matter what kind of sensory stimuli the subject might be receiving at the periphery.
It is misleading to think that the enigma of conscious color perception is explained away in terms of the wavelength composition of the incoming light. As long as we consider color in terms of the light spectrum, we can never grasp the essence of color as it appears in our consciousness. The nature of color perception is ultimately determined by the relation between the neural firing in the brain only, and has only an indirect connection with the spectrum of the incoming light.
The above argument has a flavor of a Zen catechism. Anyone who can grasp its meaning at first reading is awfully clever. Or, as may be the case, a practical scientist might just dismiss the argument with a swing of the hand. In any case, you would not expect that a philosophical thesis such as

my perception is a part of me

would lead to any scientifically meaningful conclusion. What is more, you would not think that thinking in this particular line would enrich an argument on the relation between the mind and the brain in any significant way.
Surprisingly, the above thesis turns out to be the most crucial constraint when we consider the relation between conscious perception and neural firing. Indeed, the thesis "my perception is part of me" is very much true. Most activities in the theoretical and experimental neuroscience at present ignore the full implications of this particular thesis. In what follows, I will describe some points of significance that the above thesis forces one to confront and contemplate in trying to come to an understanding of the origin of consciousness.

(Translated from the Japanese text of Ken Mogi's "Qualia and the Brain" (Nikkei Science, Tokyo, 1997) by the author)