>> Once again, a comparator does not recognize identity; it merely generates
>> a pulse (or some other output depending on the gate configuration) when
>> A - B = 0.
>Ahem. Wouldn't it be funny if neurons in your brain did that? And,
>indeed, wouldn't it be an awful shame if we had to go and say that your
>BRAIN doesn't know what red is?
Well, considering the fact that you can be essentially reduced to your cognitive hardware, if your brain doesn't know what red is, neither do you. Which would of course suggest that your brain *does* know, if not on the level of individual neurons firing. This isn't saying much, since it is doubtful your brain can be said to know "soft" or, more significantly, even "car" on the level of initial neural receptors.
Paul Churchland (via
http://www.geocities.com/Athens/Sparta/7551/silby014.html): "In the human visual cortex, there is a region known as V4. When an infant human first sees a colour, a neural pattern is set up within V4 and is reactivated when the infant is exposed to that colour again. Similar patterns are set up when the infant is exposed to other wavelengths of light. In abstract terminology, the V4 centre has partitioned itself into several labels. Each one
of these labels is a neural pattern which represents a different colour. Now, during the life of the individual, whenever a colour is experienced, the synaptic weight of the sensory input reactivates the colour's label in V4. Thus the visual cortex has identified and `labelled' the wavelength of light that is present in the visual field. The important point to note here is that these colour recognition labels must be set up at a very early age and require exposure to colour. Effectively, people have to learn how to see colours. "
It is arguable that the experience of "red" is merely brainese for "impulses triggered by a certain wavelength of light." The question remains, however, as to how the brain initially distinguishes wavelengths in the first place: where it draws lines, and why it would seem that the lines are uniformly drawn from person to person, when infant experience is doubtlessly not uniform.
Eileen Catherine Krasowski
POR, FDA, YPMB, SR, QWP, YAGS, ECY, NEXUS