Tuesday, January 09, 2007

The Dog and the violet

Let us take a specific example. Suppose I was watching a dog. I observe that the dog has white hair, that the ground below the dog is covered with violets, and that the dog's ears are triangular. Here, I presume that the dog, hair, violets, etc. are out there, and I am perceiving something that is outside me. I presume, that I perceive these things as a result of the causal connection that begins with the reflectance of sunlight from the surface of these objects, via the activation of photoreceptors in my retina, and finally the firing of the neurons in my brain.

In a sense the statement "I perceive something that is outside me" is true. But in another sense, this statement is misleading. Everything that I perceive, the dog, the white hair, the violets, are nothing but phenomenological "apparitions" caused by the neural firing in my brain. Thus, the bottom line is, the perceived image of the dog is not outside me, but "within" me. Everything I perceive, even the image of a star billions of light years away seen through a telescope, is nothing but the result of neural firing in my brain.

Even if there is a "dog" standing in a field of "violets", if the neurons in my brain do not fire in an appropriate way, I would not perceive the dog nor the violets. Conversely, even if the "dog" and "violets" were not there, if the neurons in my brain fired in an appropriate manner, I would have a perception of the dog and the violets. We thus come to a very important conclusion. The entities outside me, and my perception of these entities, are in principle separate things. It is only that in normal circumstances, a highly reliable correlation is expected between the external entities and my perception of them. (Otherwise there would be no survival value for perception!) In principle, my perception could be independent of the actual external objects that normally invoke it.

Here, it is important to note that we are not discussing merely a distinction between the real and the virtual. To be sure, if we remain in the domain of anecdotes and analogies we will be unable to deduce any scientifically meaningful conclusions. It is only when we begin to address the serious questions about the neural basis of perception that we realize how much is at stake. In the following argument, it will be shown that the thesis "my perception is a part of me" is something more than a harmless philosophical analogy. It has implications that cuts deep into the very foundations of neuropsychology as is understood today.

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


Blogger Peter Faber said...

I like this. I've been thinking about the nature of perception and how we express what we perceive. It's an abstraction I guess. "The map is not the territory" is what I'm getting at. Perhaps we should reassess our thoughts and perceptions of things, so we actually understand there's a difference between perception 'the map' and the 'territory.' It's probably a good step towards objective thinking.

1:12 AM  

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