Color Vision In The Higher Primates

[Lundb...@adobeforums.com]

Interesting article in the latest Sci Am.
If you qualify.

It appears that a subset of human females are tetrachromatic. Ann?

[Ann_She...@adobeforums.com]

I have been reading it with great interest.

One thing that I have noticed many times is that a colour that I see as distinctly on the blue-side of turquoise will be described by a man as being "Green".

I have also recoiled from other peoples computer screens because they are far too blue while the owner doesn't appear to be able to see the problem! Come to think of it, those people have all been males too.

I don't know whether I see in the dark any better than others but I do know that I can see in a photographic darkroom perfectly clearly whereas a visitor is totally blinded.
I always assumed that that was just because I was used to working in those conditions.

[Roth...@adobeforums.com]

Where did you see the reference to tetrachromatism? I read that and missed it.

Fascinating article. Thanks for posting it.

[Lundb...@adobeforums.com]

It was in the article, but I don't recall exactly where. Bees are tetra in the UV and so are some other animals as mentioned in the article. I have seen images posted somewhere that show what a bee would see, i e flowers stand out sharply from background.
The article did not indicate where the fourth cone senses in some women, but presumably somewhere in the farther blue, as Ann may be indicating.
I have long suspected that Ann is a higher primate, much higher. Your unusual ability probably set your career choice the day you were born. Ann, you should try to contact the author to find out who is doing the tetra research that he mentioned. Might be some beer money there.
Or some blue beer that everyone else thinks is green.

Another item of interest in the article is the peak sensitivity of the L cone at the boundary of yellow, definitely not red, although the sensitivity does not drop appreciably into the red.
My reading of the literature indicates that the brain invents yellow. Tests show that only R G B activates or inhibits the central and ring sensors (or do they?). Land showed that color as we call it is the result of differential reflectivity sensed by the eye, and Von Kries wrote the equations to explain color constancy that enable digital cameras to remove color cast.

[Ann_She...@adobeforums.com]

A higher primate or just a different kind of Ape perhaps — but I don't have a prehensile tail!
:)

I found this reference to "tetrachromatic color vision" (which is a subject that I knew nothing about until you posted your Link):

The pigments present in the L and M cones are encoded on the X chromosome;
defective encoding of these leads to the two most common forms of color
blindness. The OPN1LW gene, which codes for the pigment that responds
to yellowish light, is highly polymorphic (a recent study by Verrelli
and Tishkoff found 85 variants in a sample of 236 men[8]), so up to ten
percent of women[9] have an extra type of color receptor, and thus a degree
of tetrachromatic color vision.[10] Variations in OPN1MW, which codes
for the bluish-green pigment, appear to be rare, and the observed variants
have no effect on spectral sensitivity.>

<http://en.wikipedia.org/wiki/Colour_vision>

What is fascinating to me is that tetrachromatic color vision is directly related to the perception of Colours "on the blue side of turquoise".

[Lundb...@adobeforums.com]

Overheard in the Shelbourne bedroom: You are NOT going out wearing THAT!

I don't see how a true tetra as in the doctor's article would have better blue if the extra sensor is between red and green. You must actually be a large bee.

[Ann_She...@adobeforums.com]

Bzzzzzzzzzz!

:)

[Phil...@adobeforums.com]

Ann is definitely a Homo Sapien ;^)

[Ann_She...@adobeforums.com]

I bow humbly in your direction … as I swing through the forest!

:)

[Lundb...@adobeforums.com]

If you in fact are a tetra from another planet, why should i believe you?
So let's say you have the extra ML sensor between red and green, I wonder if that moves your blue peak toward the violet, as well as allowing you to see 100 million colors. You say you see blues that others don't. sRGB is so limited that surprises me.
What about the real world, especially the lady in the article who saw all kinds of ML sensor colors, do you see those?

[Paul M Norman]

One of my uncles, who was completely color blind, was used as a spotter in WWII. He flew in a plane and was able to pick out targets far more easily than men with more normal vision. I suspect that color blindness may have evolved in men because it is more useful in hunter-gatherer societies. Evolution is a slow process and men may not have caught up yet.

I also wonder about gay men. They seem to more accurately discern colors.

I'm quite lucky in that I have very good color vision.

People seem to be better at seeing colors in the middle of the spectrum. This also may have something to do with basic survival instincts. Cats can see infrared easily because they are predators who hunt in dim light. They have to able to see heat given off by prey animals. We are not equipped with infrared vision because we hunt in daylight.

Just some pet theories.

[Ann_She...@adobeforums.com]

You say you see blues that others don't.

Not exactly.

But I have heard others (and it was only men) who describe a turquoise color as "Green" that I would call a "Blue".

As for the mid-range yellows/oranges, I have no idea if I see the same way as everyone else … or not!

It has never occurred to me to have my color vision tested … beyond passing those basic tests when you apply for a Driving Licence!

[Chri...@adobeforums.com]

Try <http://www.xrite.com/custom_page.aspx?PageID=77>

If you get the "pick a country" page, pick your country, then go back to the linked page.

The test does take some patience, and on a computer display it's not perfect.

[Chri...@adobeforums.com]

Oh, and some color names are pretty subjective, even without color vision problems.

[Ann_She...@adobeforums.com]

Intriguing!

I scored "4" which is not quite "perfect" but not too shabby either!

("Perfect" is rated as Zero).

The highest number (worst vision) for my age group and gender is apparently 1520!

However, I do enjoy a calibrated wide-gamut NEC 2690 monitor so probably have somewhat of an unfair advantage.

My 4 errors were all in the brownish-olive part of the spectrum

[Stephe...@adobeforums.com]

Woohoo.. thanks for the link!

My score is 0 or "perfect!"

Seeing (pun intended!) as I'll be 60 in two weeks and am a male, I guess my 3 year-old calibrated Apple Cinema HD Display is a good complement to my own "equipment."

[Paul M Norman]

Well, I got a 4. My color is a little off in the blue/green part of the spectrum. Veeery interesting. I guess that makes me a man ;-) I'm 61. I hear that, as one gets older, the cornea actually starts to yellow. My parents both have cataracts. I hope I'm not headed in that direction.

[Phil...@adobeforums.com]

I got a 4 too.. happy with that, but the report is flawed as it does not give any idea of how many people got what score. It would be see a full distribution graph.

[PSh...@adobeforums.com]

Color me a 4 as well.

-phil

[Lundb...@adobeforums.com]

One of the first signs of approaching cataract is yellowing. Looking through trees at a bright blue sky and alternating eyes is a good test.
I just had 250 laser shots to my left eye today to attempt to get my retina back to normal after cataract surgery. I asked the doc, when do we give up? He said , in a couple years (and another ten thousand bucks).
Other than that , Mrs Lincoln, how did you like the play?

[Lundb...@adobeforums.com]

I also noted in the article that the retina configures itself as a random mosaic. It's odd that you still see moire when looking through a screen door at certain things.

[Neil_...@adobeforums.com]

My result was 4 as well on my calibrated 23" HD Cinema Display. Color "Deficiency" (which might even be carelessness as I rushed through the test) was in the blue-green area.

Interesting test, though...

Neil

[Roth...@adobeforums.com]

I didn't do too well with a 16. But oddly enough the chart showed the errors where very evenly distributed over the whole spectrum. So I would like to think it is just my crappy monitor! :)