http://en.wikipedia.org/wiki/Tetrachromacy

damn birds seein' up all the cool colours
















although apparently, you might be seeing these colours right now

Quote:

Possibility of human tetrachromats

Humans and closely related primates normally have three types of cone cells and are therefore trichromats (animals with three different cones). However, at low light intensities the rod cells may contribute to color vision, giving a small region of tetrachromacy in the color space.[5]

In humans, two cone cell pigment genes are located on the sex X chromosome, the classical type 2 opsin genes OPN1MW and OPN1MW2. It has been suggested that as women have two different X chromosomes in their cells, some of them could be carrying some variant cone cell pigments, thereby possibly being born as full tetrachromats and having four different simultaneously functioning kinds of cone cells, each type with a specific pattern of responsiveness to different wave lengths of light in the range of the visible spectrum.[6] One study suggested that 2–3% of the world's women might have the kind of fourth cone that lies between the standard red and green cones, giving, theoretically, a significant increase in color differentiation.[7] Another study suggests that as many as 50% of women and 8% of men may have four photopigments.[6]

Further studies will need to be conducted to verify tetrachromacy in humans. Two possible tetrachromats have been identified: "Mrs. M," an English social worker, was located in a study conducted in 1993,[8] and an unidentified female physician near Newcastle, England, was discovered in a study reported in 2006.[7] Neither case has been fully verified.

Variation in cone pigment genes is widespread in most human populations, but the most prevalent and pronounced tetrachromacy would derive from female carriers of major red-green pigment anomalies, usually classed as forms of "color blindness" (protanomaly or deuteranomaly). The biological basis for this phenomenon is X-inactivation of heterozygotic alleles for retinal pigment genes, which is the same mechanism that gives the majority of female new-world monkeys trichromatic vision.

In humans, preliminary visual processing occurs within the neurons of the retina. It is not known how these nerves would respond to a new color channel, if they could handle it separately or would just lump it in with an existing channel. Visual information leaves the eye by way of the optic nerve. It is not known if the optic nerve has the spare capacity to handle a new color channel. A variety of final image processing takes place in the brain. It is not known how the various areas of the brain would respond if presented with a new color channel.

Mice, which normally have only two cone pigments, can be engineered to express a third cone pigment, and appear to demonstrate increased chromatic discrimination,[9] arguing against some of these obstacles; however, the original publication's claims about plasticity in the optic nerve have also been disputed.[10] People with four photopigments have been shown to have increased chromatic discrimination in comparison to trichromats.[6] Each of the three cone types in a trichromatic human retina can pick up about 100 different gradations of color, and the brain can combine those variations so that the average human can distinguish about 1 million different colors; a true human tetrachromat would have another type of cone, and its 100 shades theoretically would allow them to see 100 million different colors

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think the 1,000,000 colours you see on DMT are cool? try 100,000,000

blewmeanie said:

What do you see?

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Damnit! Birds get to fly and see all sorts of -inducing colors? No fair!

mufasa said:

three circles containing smaller circles.
red, orange and green from left to right.

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