At 01:05 PM 11/21/02 -0600, Mark A. Freeze wrote:

... When my mind "see's" the color I have labeled "Blue", it "see's" basically the same as everyone else's mind does for that color. Now your name for the blue color may be "H214x", but our minds still perceive the color as the same regardless of the label, unless you have some damage to your eyes or brain that would cause a color-sensing defect. ...

I have always thought so, based on a mechanistic view of the systems involved. The "normal" human eye has three types of cones with peak sensitivities spaced on the visible spectrum to provide "optimal" human color vision. There are two main types of color blindness: dichromat and shifted trichromat. I don't know if there are many truly color blind (grey scale only) people, and most of these are probably related to brain defect/injury or albinism (complete lack of pigment). Dichromats have only two types of cones, so their internal reconstruction of colors is substantially less sensitive. Shifted trichromats have one or more types with peak sensitivities shifted so that two are closer together on the spectrum, and consequently provide less resolution in that part of the spectrum. (The cones are sensitive to bell-curve distributions rather than discrete wavelengths, which is how we perceive colors between and beyond the peaks.) Severity of degradation varies with the amount of frequency shift. I have a mild case of red/green color blindness, which means my low energy sensors are closer together than normal; but I have absolutely no trouble with anything other than the really subtle color test cards. I have done my share of resistor color code reading, have properly balanced photographic color prints, and am able to discern the difference between copper and gold. Since we are, by the nature of our 98+% shared DNA, wired basically identically, one can argue that our optico-neural wiring, and hence function, is basically the same. In mammals, certain functions such as clear stereographic vision and motion detection require sensory stimulation to train (rewire) the neural net in the visual area of the occipital lobe. But I see no reason to doubt that color vision is hard-wired from the start. Aloha, Bud ========== For a small collection of Fractint fractals, visit http://value.net/~mchris/fractals.htm Bud's Fractal Pages