Color perception arbitrary?

[Rayaan]

http://www.youtube.com/watch?v=l8_fZPHasdo

[Annik]

Visual light is determined by the wavelength of the light wave.


I suspect we get the specific color (such as red being longer, rather than getting green from a long wavelength) just from the ways our eyes absorb these waves.

[Angrboda]

I think TEGH is asking an additional question here, which someone else touched on, namely, why do the colors have the qualia or subjective experience associated with them that they do. That may or may not be biologically constrained, I don't know. It is akin to asking why, in our subjective world, "up" is perceived as "up," instead of the directions being reversed? Daniel Dennett has written an influential paper, which I sadly have not read yet, which suggests that if our qualia or subjective experience were changed, we would have no way to detect that change (or so I've heard it summarized; "Quining Qualia"). There is the classic experiment in which a person is fitted with spectacles which optically turn everything upside down. After a few days of wearing the device, the world rights itself again, mentally, so that even though up is down and down is up from the perspective of the eye itself, the brain has remapped itself to present us with the standard "up is up" perspective. So it would appear that, for the brain, certain subjective aspects may have "default values" which the brain will re-establish if it can. It's also worth noting experiments in which they create a rectangular array of tactical stimulators, and hook those up to the output of a camera with the same resolution; with practice wearing and using the device, subjects report that they "see" things through the device, much as they would see objects visually through the eyes (IIRC). So it would appear that not only do there appear to be default ways of organizing our internal world, those defaults can be adapted to stimulii which are far removed from the sense organs that the modality likely evolved to service. In Damasio's Self Comes To Mind, he suggests a model of memory and perception in which the circuits that serve perception are, in a sense, bi-directional, in that when an image is registered on the retina, theses circuits function to encode the image for storage; but when a memory is retrieved, a sort of reverse process occurs in which the memory activates the visual circuits normally used in processing perception. (To the best of my recollection/understanding.) We don't normally think about it, but it's somewhat amazing that we can "imagine" novel things and "picture" them in our mind; why do we see them as a visual representation? How is that possible? There are people with unique perceptual modalities; the sighted from the perspective of the blind; and the synesthetes who smell colors or see musical notes from the perspective of the rest of us. No matter how you try, it's nearly impossible to imagine experiencing a sensory modality that you don't possess. Is this a consequence of imagination, memory, and perception all sharing the same imaging hardware? I suspect it is, but I don't know what kind of support for such an idea there is. It seems to me, though, that it would explain many things. (A question related to this is why or how we experience the sounds of speech as "meaning" and "sense" rather than as just sounds? How did we adapt from creatures who experience language as sounds to one that can experience sights, writing, as language?)

[Rahul]

Visual light is determined by the wavelength of the light wave.

But not how your brain perceives it.

[FifthElement]

I scored a 23 on that test on a scale of 0 to 99, 0 being best. I'm hoping that's at least average. I have to wonder how valid such a test is on a computer screen. I know print is still able to reproduce finer gradations of color.

Scored 24, for someone who is 50 that's not that bad, i guess, lol