Mutant Tetrachromat Females Found

Hydrophobe writes "Red Herring reports that at least one living human female has four-color (tetrachromat) vision. Apparently, genetics dictates that all such tetrachromat mutants would be female. Compared to them, the rest of us are partly colorblind - they would be able to see colors beyond the standard three-axis RGB scale."

Comments

Re:Sound as subjective experience [O/T]

[Anonymous Coward]

There may be hues of color that are undetectable by a "normal" (trichromatic) human eye but that are quite jarring to a tetrachromatic eye - much in the same way that someone who detects very high or very low pitch may think differently about a piece of music, or a type of noise, than you or I might.

As someone who can hear a bit into the ultrasound range, I find that most music doesn't have noticeable components at such high frequencies; the main effect is that I can hear the presence of electronics, especially transformers, CRTs and malfunctioning speaker elements, to a significantly greater degree than most others.

Re:Pigeons & Pentachromats

[Anonymous Coward]

More combinatorics. Seems like the trichromatic's have a 7 color palate, while the tetrachromatics have a 15 color palate. Likewise, and penta would have a 31 color palate. Anyone see a pattern? Yep, it's good old n^2 - 1. So this women basically has twice the number of hues in her world as the rest of us motals.

There is also an interesting LandSat connection here. Measuring intensity along additonal frequency bands is what allows satellites to identify different types of terraign features such as types of rocks, kinds of crops, health of crops, etc. These secondary and tertiary combinations are enough to make the ID. If we could see with in these extra frequency bands, then we could look at the ground below from airplanes and make similar determinizations. Different terraign would appear as different hues.

As a side note, I love how we AC's never get modded up.

A simple request

[Anonymous Coward]

Should anyone meet a colour blind man, (and we're nearly all men) please, please, don't find this somehow amusing, and start doing stuff like "what colour's this then?", (especially not when pointing to a vivid yellow object for example). Colour blindness is a real disability. It bars you automatically from many kinds of work, even when it is not particularly severe, and can be on occasion dangerous to the sufferer. A colour-blind person is not an object of fun any more than anyone else with a disability. Being mocked because you make a mistake in colour identification is demeaning and upsetting. I'm sure there are many other colour-blind people out there who can identify with what I'm saying.

Also, a word to those working in GUI design, or using colour-coding for some reason. Please, please consider us. Some colour uses I've seen deployed are hard for people with good colour vision, let alone people like me. It's shades of colour that cause the most problems. For example, a pink, pale green and light brown row of buttons really will be difficult for people with RG colour blindness (the most common). A little thought can make all the difference here.

Anonymous yes, but in this case, no Coward.

Re:We already knew this

[Anonymous Coward]

This happens because certain personality types of girlfriend will buy you clothes that you don't look *quite* good enough in, so that other women won't be rabidly interested in you. Other kinds of girlfriend, however, will insist on having you look as good as possible in the eyes of other women, since that type of gf thrives on using you as a bragging point. Basically, it depends on how insecure your gf is, and how she handles the insecurity.

Re:The story reports only of the possibility

[hank]

You mean to tell me they're not red? I find that a little hard to believe. After all, seeing is believing...;)

Re:"mutant"

[volsung]

Say what? Do you have a source for this one?

Re:Well

[lordhades]

Yeah, since there's no way a woman could be that wealthy herself...

Re:We already knew this

[AxelBoldt]

Half her sons.

--

Re:Nit Pick Alert

[AxelBoldt]

If I recall right, R and G are actually rather similar spectrally, with somewhat broad humps in the long end of the spectrum, while the B dye has a very different spectrum with a sharp peak near the short end of blue.

True, and the reason is that R and G come originally from the same gene, while the B gene sits on a different chromosome altogether. Most mammals have only two dies (they were active mostly at night) but at some point there was a mutation which duplicated the R gene and modified it slightly to turn it into G.

--

Mutant technocrat females found

[embobo]

Mutant technocrat females found: that's how I read. I thought to myself: Bruce Perens has finally gone off the deep end. He is making an army of mutant females to further his politcal agenda. Or he would have, had his plot not been uncovered in time.

Re:"mutant"

[psychosis]

Although I think that X-Men is a kickass comic/movie, they really did put a downward spin on the word "mutant". (Yes, yes, them among others, but you know what I mean...)
Technically, a mutant is (per dictionary.com) "An individual, an organism, or a new genetic character arising or resulting from mutation." - basically anyone that is different based on non-normal genes. You could probably say that we are all mutants in some way...

Re:We already knew this

[jacoby]

My wife already knows what a loser I am.

Wife: Did you do foo?

Me: I left that for you, since you handle the money

Wife: Do you know what you'd do without me?

Me: Probably starve

Wife: You got that right.

I work, she takes care of the money, and I get to play guitar and buy occasional CDs and computer hardware. I'm not complaining.

Re:Between Red and Green!?!?!?

[Rift]

Your eye is already sensitive to UV light (very sensitive in fact), but the cornea blocks it. For those people who had the first rounds of artificial corneal transplants, they could see in low-light situations, some could even read in light that most people found themselves hitting walls in!

The difference is that the untreated plastic would allow the UV to pass. The UK and US (possibly more undocumented)both had a (Very) short stint where they would have agents in the intellegence business undergo this surgery to be able to operate at night.

The drawback to this amazing vision? premature loss of vision. Sure, the eye is sensitive to UV, as it destroys the retina and causes blindness. Hmm.. guess I'll stick to a flashlight.

Damnit... this is discrimination...

[vkulkarn]

I'm going to call my lawyer... maybe he'll be able to figure out who I should sue for this. I mean, just because I'm a guy, doesn't mean that I shouldn't be a Tetrachromat... That's so unfair... If I had found this out as a child, think of what it would have done to my self esteme... Think of the children... It's all about the children...

Ummm... yeh... time to call a lawyer now...

:)

Re:Klinefelter's Syndrome

[boinger]

No. Read the article. You need two Xs to be a tetrachromat. So, the Klinefelter Syndrome guy could (in theory) be a tetrachromat, but the XY kid could not.

Where are these other colors?

[James Manning]

What wavelength range (in angstroms, please) are these colors? I would imagine it is what we normally tag as ultraviolet... otherwise, most remote controls would be quite bizarre for these people :)

Re:Where are these other colors?

[James Manning]

nevermind... although "between red and green" doesn't help much

Re:Where are these other colors?

[general_re]

I don't think the idea is that tetrachromats see "other colors."

I think you're exactly right here. They don't see some color on a frequency that the rest of us are incapable of perceiving...although it would be extra-cool if they saw slightly into the near-IR or UV ranges. Since the average noncolorblind human perceives the colors in the visible spectrum just fine, there aren't mysterious "new" colors in that spectrum that only tetrachromats (new word of the day) can perceive. Instead, it seems that they would have a "richer" visual experience than the rest of us do, seeing subtle color differences that others don't.

I suppose that this would be akin to the effect that you see when comparing the same picture in 8 bit vs. 16 bit vs. 24 bit color, where the higher color depths seem richer and more lifelike - this would be the next step beyond...now that I think about it, the standard 24-bit color wheel would probably look rather "unsmooth" to them, as a 256 color wheel would to you or I.

Maybe the best way to imagine it would be to think of it as spending your life on some wonderfully mild psychoactive drug...;)

Re:Where are these other colors?

[ptbrown]

Actually, it helps a lot. Think about what color most people's skin is.

(ROYGBIV)

Re:Where are these other colors?

[itarget]

Since the human brain has about the same consistency as pudding, I daresay it's very malleable. =)
---
Where can the word be found, where can the word resound? Not here, there is not enough silence.

Re:Where are these other colors?

[Actinophrys]

Just something the other comment didn't mention: you can only show the color space in a 2-D plane if you treat it trichromatically. Then it is a 3-D space, defined either by the three primaries or the axes of the plane plus saturation.

To properly represent colors treated tetrachromatically, you would need three dimensions (plus saturation), since yellow could no longer be represented as a linear combination of red, green, and blue.

Re:Where are these other colors?

[NonSequor]

It's not ultraviolet or anything fancy like that. The extra color this woman has is between red and green. Now if you took the gene generating the "gred"-sensitive cone and played with it until you had an ultraviolet-sensitive cone, you could put it back in place of the "gred" cone. Or you could leave the "gred" cone in and have 5 colors.

On the subject of seeing infrared, I remember playing with the remote to a camcorder and seeing that the camcorder could pick up the signal. It showed up on the screen as a white flash. Apparently the camcorder was sensitive to the infrared spectrum and for whatever reason shifted it into the visible spectrum in the signal it sent to the TV. Although, I imagine that the video signal doesn't have any means of storing infrared stuff.

"Homo sum: humani nil a me alienum puto"
(I am a man: nothing human is alien to me)

Re:Where are these other colors?

[Logic Bomb]

I don't think the idea is that tetrachromats see "other colors." They have cells that are sensitive to a fourth frequency somewhere in what we know as the visible band of light, where most of us have cells sensitive to only three particular frequencies (which vary slightly among individuals, but are always supposed to be red, green, and blue). What this means is that when you look at two red shirts and think they're the same color, a tetrachromat might be able to see that they are in fact slightly different colors. It's kinda neat, but it doesn't give night-vision or anything like that. The real significance, like the article said, is that this could tell us something fundamental about the human brain and its malleability.

Re:Where are these other colors?

[mangu]

when you look at two red shirts and think they're the same color, a tetrachromat might be able to see that they are in fact slightly different colors

Maybe, and maybe not. Having a fourth color receptor will not necessarily be an advantage, since three receptors are enough to recognize all the colors between infrared and ultraviolet, where most of the Sun's light emission falls. The main advantage is in distinguishing between slightly different levels of saturation, not hues, and only for nearly 100% saturated colors different from red, green, or blue. As most colors found in nature are less than 50% saturated, there's no big advantage in tetrachromacity.

If there really was a great advantage at a small cost, this mutation would probably have spread through the whole human race by now.

Re:Where are these other colors?

[mangu]

the physical pigments and fibres that we mix for everything else to make hues as well, and wherever you acheive a hue by mixing colours, you risk it looking different to a tetrachromat

Why? We, trichromats, look at a CRT and see green as green, but the addition of green and red as yellow. Why should the addition of an extra primary color make any difference? Tetrachromats are still limited to the same basic model as us: seeing a continuous range of colors from a combination of a discrete number of primary colors.

The same problem occurs when we print colors. In a CRT we have one set of three primary colors: red, green, and blue; and in a printer we have to generate the same colors from a different set of primary colors: cyan, magenta, and yellow. This means that some colors in a CRT cannot be printed, and some colors in a printer cannot be shown in a CRT.

If you show the color space in a 2d plane, you'll see why: each set of primary colors describes a polygon, where distance from the center sets the saturation and angle from the vertical sets the hue. The tips of the primary colors are the most saturated colors, which can be reached only by a vector pointing in exactly that direction. The region near the center is where less saturated colors reside, that region can be reached by any combination of primary vectors. By adding more vectors to your polygon you are making it closer to a circle, and increasing its area. But the difference is near the tips of the vectors, the low-saturation region is covered by any combination of at least three primary vecotrs.

Re:Where are these other colors?

[-Harlequin-]

The main advantage is in distinguishing between slightly different levels of saturation, not hues,

Not entirely. I'd say the big advantage would be from compound coloured objects. Eg an orange shirt (that is actually woven from red and green fibres) will look orange to us and something completely different to a tetrachromat. It's not just RGB monitors that are geared to trichromats, but the physical pigments and fibres that we mix for everything else to make hues as well, and wherever you acheive a hue by mixing colours, you risk it looking different to a tetrachromat from a pigment or fibre that is genuinely that colour.

Re:Where are these other colors?

[-Harlequin-]

the physical pigments and fibres that we mix for everything else to make hues as well, and wherever you acheive a hue by mixing
colours, you risk it looking different to a tetrachromat

Why? We, trichromats, look at a CRT and see green as green, but the addition of green and red as yellow. Why should the addition of an extra primary color make any difference? Tetrachromats are still limited to the same basic model as us: seeing a continuous range of colors from a combination of a discrete number of primary colors.

A colour blind person also uses the same basic model, but more (or fewer) points of reference certainly makes a difference.
When we see yellow, obviously it means that there is a response from both the R and G cones (as both can see yellow). However, we can get the _same_ response from the right mix of red and green, thus an RGB monitor produces yellow. But a tetrachromat has a cone for yellow, and that cone is saying "there is nothing here" (it will pick up a little bit of red and a little bit of green at the extremes of its senstitivity, but nothing in its peak area), thus the tetrachromat can distinguish faked yellow created by mixed fibres or RGB, from true yellow as emitted, by say, an LED.

The point is that while we can all see yellow, some of the colours that our brain assumes are yellow actually contain no light in the wavelength of yellow, and the tetrachromat could distinguish the difference.

Or to put it another way, while we all use the same method as you say, many products of our 3-primary colour techniques won't withstand 4-primary scrutiney.

Re:Where are these other colors?

[dmatos]

Sorry, the article states that the extra photoreceptor cones are sensitive to a wavelength in between red and green, directly on the range of visible wavelengths. At the most extreme, they would be receptive to a yellow-orange colour, although most of them hover around slightly different shades of green or red. No UV vision for you. (PS - aren't most remotes IR nowadays? Less harmful if you aim it at your eye).

Sqant!

[QueenFrag]

the fourth color was found a while ago: check out www.negativland.com for more information on squant.
and, contrary to this report, anyone can see it with an appropriate monitor (and browser plugin)

Nice to hear...

[cluening]

...that after all these years of color blindness it may just be the whole population who is color blind. Now nobody can complain to me for not matching things up correctly!

Re:"mutant"

[ocie]

Yeah, I for instance have brown hair and blue eyes, something which neither of my parents has. This does not make me a mutant.

Re:Yes it is the exact term you would use.

[Mr Z]

Actually, depending on how the four colors are distributed, the male children may not be completely color blind, just differently sensitive to color. For instance, suppose the mother has "Green" and "Red1" on one X chromosome, and "Green" and "Red2" on the other. Suppose "Red1" and "Red2" are sufficiently far apart in their response curves that the mother is a tetrachromat. Any sons that she has will still be trichromats.

The reason the reasearchers looked specifically for mothers of colorblind men is that it narrows the search. It means that one X chromosome has both "Red1" and "Red2" on it (or perhaps "Green1" and "Green2"), rather than spread across the two X chromosomes. It makes the search easier, but I see no reason why a tetrachromat must have the two nearly identical colors on the same X chromosome.

With this in mind, I wonder if women just generally have better color perception then men, since they'll tend to actually have up to five chroma channel, since the reds and greens in both X chromasomes aren't going to be identical to each other. The differences might not be large enough to really affect their vision deeply, but it might add a subtle touch. Thoughts? Maybe that's why my fiancee and I always argue about what color something is...

--Joe
--
Program Intellivision!

Re:Argh! Read article first, then comment!

[Mr Z]

If the Males can't see the difference, though, how does this improve desireability (unless it becomes one of those unconsciously perceived bits...)?

Hey, maybe she's into other women, and they decide to have kids by visiting the local sperm bank. I guess that'd be a case of two tetrachromats hooking up and passing their unique genes on, eh? You never know in today's world.

(And if that is the case, I say more power to them! I'm all for a little diversity.)

--Joe
--
Program Intellivision!

Re:Yes it is the exact term you would use.

[Mr Z]

The poster a couple levels up talked only of letting this mutation spread into the populace, which implies simple reproduction, not genetic engineering. Animal husbandry and genetic engineering are two different things. If I pick a mate because I like some aspect of that mate and subsequently have offspring, is that wrong? Does it matter whether that critereon is "explicitly vital to the existance of the species"?

I find the concept of genetically engineered children to be repugnant. The thread I was on wasn't talking about that though. I didn't miss your point, but it was covered in a different thread that I just chose not to participate in.

--Joe
--
Program Intellivision!

Re:Just wondering

[Mr Z]

As you point out, it does no good in the framebuffer.

Actually, if your video card does real-time compositing with an external video source, that alpha channel is pretty darn handy.

--Joe
--
Program Intellivision!

Re:Clothes matching

[JanneM]

She has it backwards, I think. The question of wether something matches (for instance) is a subjective experience derived from sour sensory input, not an objective state of the world (there are no natural laws determining the color compatibility of various objects). For her, certain combinations of colors do not match, whereas the same combinations do match for trichromats.

Thing is, most people seeing that combination will be trichromats, so it's really their opinion (as well as the opinion of the wearer) that matters, not hers. Turn it right around and assume she perceives some combinations as matching when everybody else thinks it clashes horribly. Should we all wear clothes we think are horrible so that she sees them as matching (as her color vision is more acute), or should we try to match for the greatest number of people?

Per definition, she is the odd one out, not everybody else, so she would be a bad, rather than good, choice as color advisor.

I hope not: Franken-Kids, oh my

[PhilosopherKing]

As per the article, this mutation is from an X chromosome having either a double set of red or green and a lack of the other. So, without genetic manipulation, male children from these women would have approx. a 50/50 chance of being color blind. (Approx., since the egg X mix in the article can 'correct' the problem) I personally feel that's an immoral thing to do (intentionally introducing a gene that needs technology to "maintain" it)

But, as per you said, we would have the excuse of:
"But mom, you see 4 colors, so I can only see 2, it's not my fault i'm wearing red/green plaid pants with a pink shirt." (or perhaps you have the golfer gene)

And everybody knows what we should do with those!

[Pac]

Kill them all! Mutants are bad, they are a menace to the very human existence in planet Earth. We let the tetrachromats live now, the next thing we will know is that invisible mutants are hiding in our daughters bedrooms, telepath mutants are reading our dirty secrets out of our minds and little green man from Betelgeuse are cropping in the garden.

So I repeat, kill the mutants now while there is still time!

How to see the extra colors

[Eric Hillman]

Thanks to the forward-thinking folks at NewHew, many of us have been artificially tetrachromatic for some time now... The fourth, newly discovered primary color is called "Squant" and you can find out more about it at http://www.negativland.com/squant/index.html. Unfortunately the plugin is not available for Linux, yet.

Happy Squanting!

--
perl -e '$_="06fde129ae54c1b4c8152374c00";
s/(.)/printf "%c",(10,32,65,67,69,72,

Re:So why do women ask men, "Does this match that?

[DavidTC]

We do, in fact, have a name for the color that's in the infrared spectrum...it's 'infrared'. ;) We don't need to go around inventing more names if genetic engineering gives it to us. :)

-David T. C.

Re:Want to see if you're colorblind?

[Tycho]

On a similar topic this is what it would look like if you had various types of Colorblindness.
http://www.colorfield.com/FilterGallery1a.html

Re:propogating into the general population - doubt

[HeghmoH]

The basic idea is there, but, despite the simplicity of the principle, it can get complicated.

For example, there is a basic drive towards altruism, generosity, helping the fellowman, whatever you want to call it, in a lot of people. Taken from an individual viewpoint, this drive should not be there; using valuable time and resources to aid somebody else instead of yourself will hurt your chances of reproducing. However, taken from the view of the group, the drive is beneficial. When those with excess help those in need, everybody benefits in the long run. This fact counterbalances the individual detriment sufficiently that some level of generosity is very common in humans. The opposite is seen, too. There is some species of bird where, when the eggs hatch in the nest, the strongest of the young will kick the rest out of the nest, killing them from the fall or leaving them to starve or be eaten. These are not just anonymous strangers, but the baby bird's own kin! Of course, there being fewer mouths to feed, the individual does better, at the expense of his siblings.

Another example. Intelligence is obviously a survival trait when man is outside of civilization. All other things being equal, a smart man will have a much better chance of survival than a dumb man. The same would seem to go for nearly any creature, not just humans. So why isn't every animal as smart as we are? Why aren't we smarter than we are now? Because intelligence has a high cost associated with it. Smarter brains mean larger and more complex brains. While resting, the human brain uses on average one-quarter to one-third of the body's energy. Think of how much less food we could survive on if we didn't have to feed that mass of gray matter! Also the size of the human infant's head is the cause of many difficulties while giving birth.

As to the idea of current conditions favoring the stupid, it works from an individual viewpoint but I think not from a group viewpoint. For a group to survive, it needs some proportion of smarter people, and I think that still applies enough today to counter the possible individual selection towands less intelligence.

Re:Pigeons & Pentachromats

[kabrakan]

No i'm real and ALL OF YOU ARE ZOMBIES.
--

Re:Cool...

[grappler]

Well, if you want to be anal, you'll notice that I never technically called anybody a name. I was just venting.

I argue with them often, though, and it is they who start making personal attacks and spouting nonsense. I don't actually make statements like those to a person when I'm arguing with them.


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Re:Pigeons & Pentachromats

[grappler]

that was the starting idea in this thread. I shifted to the zombie thing, and then you brought it back to the color thing.

No big deal, tho


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Re:Cool...

[grappler]

not so much anymore :-)


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Re:Cool...

[grappler]

Well, the ones that I've argued with would have a hard time with this - they are fond of saying that no advantageous mutation has ever been observed, or could ever occur (despite overwhelming observational data to the contrary).

The fact that some X chromosomes could have an "off green" or "off red" gene sounds like a mutation to me. Whether it is an advantage is debatable. If it in fact allows a person a more acute perception of light, I think it would be an advantage.


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Re:Cool...

[grappler]

same thing they say to everything:

*duh*, *snort*...

"you know, the Second Law proves the Bible right..."

hic...

"Are you saying I came from a *shudder* ape?"

scratch...

"So I suppose we're all one big accident, huh?"

I hate those people with my very soul.


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Re:We already knew this

[Sloppy]

Considering the dozens of variations of this same joke, posted over and over in this discussion, I think Slashdot should address the redundancy. For stories such as this one, which suggest a very obvious type of joke or comment, I think that when the story is submitted to Slashdot, the submission should come with template joke threads preinstalled. Then everyone would know to put all the variations of the obvious joke all in one place.

---

Re:Pigeons & Pentachromats

[HiThere]

It's actually less important that it sounds, unless the actual range is extended. Within the range the ordinary cones already have an overlap in their sensory response (i.e. in between blue and green, both cones respond slightly), and the rods tell us how strong the signal is. Four primaries would provide another intermediate peak, but there seems no clear advanage in signal processing (despite other comments).

Unless it extends the range. But that seems unlikely. The design of the eye is optimized for a particular range of wavelengths. Above or below that range it tends to either be damaged, or just not process them. (I believe that infrared is absorbed quite quickly be the fluid that fills the eye, but don't remember precisely, and sure don't want to do the experiment). UV is damaging to the eyes (one reason that I wear glass glasses -- though I understand the modern plastics do just as good a job, but they scratch a lot easier, so I still haven't switched).

Caution: Now approaching the (technological) singularity.

Evolution: Well, actually...

[LordMyren]

well actually, if you look closely, evolution is supposed to happen because the bearers of certain traits seem to not make it to breed. While the entire issue of not being able to breed doesnt show up much anymore, there is one thing we have to note. The rich tend to breed with the rich, the poor tend to breed with the poor. Sure, there is a whole lot of mixing, but none-the-less, given a couple million years of our current state, we'd have a pretty stratified gene pool. Myren

+1, Funny

[weston]

Thank you. I needed the humor.

Re:Just wondering

[Mr. Piccolo]

So what?

There's no alpha channel in the framebuffer.

Re:Just wondering

[Mr. Piccolo]

At last we'd have a use for the extra 8 bits in 32-bit color modes than just padding to make things faster.

Re:Maybe

[Nightpaw]

Silly boy, chicks don't play computer games.

hmm

[FatSean]

Probably just the radiation from the LED spilling over into the near-visible spectrum combined with your sensitivity to red colors.

Re:hmm

[egm]

Thats a good point and it makes me think that I should try a pure IR source in order to verify that. Anybody with a good CO2 laser to do some tests? :-)

Re:Yes it is the exact term you would use.

[Tarnar]

If the 4 color vision is a good mutation, it will hopefully propogate into the general population eventually (well, half of it anyway :)


Oh yeah, really great.. Especially all those colorblind male children that come of it.. :)

There MAY be a evolutionary reason for this...

[ShieldWolf]

When I studied perception we discussed these theoretical individuals and why it would be that only women could genetically possess the gift. The hypothesis that the professor gave was that perhaps these women could perceive minute colour variations in there children's skin and thus notice if the were getting a fever or other illness.
BTW, to those of you who say there is NO way we would imagine what the world is like for these people, note that they simply have a slight differentation between two similar cones, and any preceive colour variation would likewise be slight. They would more likely than not simply be able to perceive greater variability among reds and greens, as opposed to being able to see a new colour Xeen or something. ;) Of course you CAN test this: show them various colours and ask them if they are perceptively as different ROYGBIV ;)

-ShieldWolf

Something that I have thought about for a while

[mog]

Vision has always fascinated me. The idea of looking through someone else's eyes likewise. I often, for fun, trick my brain into trying to prove to itself that how I perceive red is the same as other people perceive as the same. It could be that each person has a different calibration - that is, they perceive colors differently.
This idea in general is totally wild to me. The idea that what I perceive as the green of grass might be, to someone else, what I perceive as neon magenta. I realize there are issues with rods, and the brightness of light that a color reflects; but the point is still there. I don't know of any way to determine *perception* of colors.
I just find it perplexing and something fun to think about.

Re:Something that I have thought about for a while

[putzin]

Yeah, I have often wondered the same thing but to no avail. It would be like understanding what it would be like to see with 4 types of receptors instead of 3. There is no means of discovery on this one and therefore will remain a mystery of the universe much like the genious of the writers of the Simpsons.

Re:Something that I have thought about for a while

[Emma_Syncler]

In terms of practicality, measuring color by exact wavelength/frequency rather than names might be the way to go. The argument of "Is the green of my grass the same as yours?" is worn-out. We seem to have a societal agreement that grass IS green. One grass = one wavelength/frequency, a different grass = a slightly different wavelength/frequency. Just to make things even more interesting, there are some cultures that don't have color values for as many colors as we're using. I don't have my Sociolinguistic class material handy, perhaps someone out there has more specific info, but there is a tribe in Africa that has something like 'light' and 'dark' for colors. We would talk about orange, purple, indigo... they would call ALL of them 'dark.' And if I recall correctly, in the Russian language there are two different terms for 'blue' that we make no distinction between in America.

Guess it all comes down to measuring the length of wave/frequency etc that is being shown, and either the person sees it or they don't. I guess you could take it another step and ask them what color term they would use for it, just to see what social conditioning has done to their perception.

don't know if this made a lot of sense, but figured someone else might pick up the ball and run with it.

Re:Something that I have thought about for a while

[SEWilco]

"...looking through someone else's eyes..."

I believe a search here on Slashdot for "cat eye" will let you see through the eye of a cat.

a haiku

[mog]

trichromats seeing
as the mouse boxed in from light
tetrachromats laugh

Re:Graphic Designers

[MindStalker]

Not, nessesarly so, in the real world we design things for trichromats, and the dichromats have a hard time surfing our web. Luckly everything is currently designed for trichromats and the tetrachromats just get the oportunity of thinking that it looks that much better. Now imagine if something was designed by a tetrachromat that saw 2 colors as being diferent, and expected everyone else to see the same, but they didn't. You could easily have great confusion.

Makes up for...

[scooby-doo]

I guess God had to give women something men didn't have, since he already gave us the ability to pee standing up :)

Re:Makes up for...

[triticale]

http://www.restrooms.org/standing.html

Squant

[majcher]

Does this mean that we finally have people that can see squant without the special plugin now?

Re:Squant

[aenomie]

i don't think you get it ;)

GM user interfaces

[TimAllen]

I liked the suggestion that genetic engineering was the answer to poorly-designed web page interfaces. I wonder what other ui atrocities can be fixed by a snip of the gene shears...

Now my EYES are obsolete.

[slurry47]

36" TV < 16:9 HDTV

21" CRT < 22" LCD

me < tetrachromat

One more option to select when I get my bionic eye installed.

RGB +1, IR, thermal, zoom . . .

"That's nothing. He can HEAR pudding."

Re:Yes it is the exact term you would use.

[SEWilco]

That's why superheroes in the real world always wear those greenish uniforms? The normal humans can't see them flitting about, particularly at crime-fighting rush hour.

Ultraviolet sensitivity

[Polo]

A fascinating tidbit is that the human eye is also sensitive to ultraviolet light - but this is filtered out by the cornea and never reaches the retina.

During World War 2, they used people with replacement corneas to help coordinate nighttime paradrops. They had special markers that would be visible if you could see ultraviolet, but not to people with normal corneas.

So if you have cataract surgery when you get old, there might be a silver lining...

Re:Yeah, when she can see IR/UV, she'll be a mutan

[The Welcome Rain]

Unlikely. Glass reflects IR. That's why cars get hot so quickly in sunlight.

--

[OT] .sig question

[The Welcome Rain]

If whiskey is the water of life, what then is water?

--

Re:Yeah, when she can see IR/UV, she'll be a mutan

[The Welcome Rain]

No. Here's how it works.

A light photon gets through the glass, hits a surface, loses some of its energy and becomes an IR photon. It then hits the glass, which reflects it. Thus, IR photons build up inside the car. Thus, it gets hot.

Other evidence: Put an IR occupancy sensor next to a doorway with a window in front of it. People passing by in the hall will trip the sensor; their IR image is reflected off of the glass, which acts like an IR mirror.

--

Re:Photoreceptors... still don't get it...

[tommyk]

OK... I looked at the site... and got possibly more boggled, or maybe I understand.

One thing that puzzled me from the site... it seemed to imply these three different chemical receptors aren't actually three different receptors, but one has different sub-type receptors in it... why not just say there are four?

Nevermind...

Anyway, i read this, and it seemed partly clear how things work, the chemicals absorb light across different frequencies which "overlap" to some extent as you go up the frequency chart. So, the result is that each "color" we precieve has a unique reaction it creates in these three ( or four ) types of receptors. Great, neat...

But, they seem to cover a whole span...there are no blanks where a "color" would hide...

When you look at a rainbow, or the light through a prism, there aren't any blank spots.

So, I guess my question is: would having an extra receptor really help? It seems like it would just overlap anyway... it might make it a little easier to see that this color didn't match that, but... ummm... even with just three receptors, that color is going to have a unique three-part signature, it may be trickier to see a difference just like it's possibly more precise to have a four-way fix on your position than a three way... but the truth is, provided the position is in a unique part of the set, you can get away with two numbers covering the same area... or one, as long as it's unique to that part of the spectrum...

Suppose that you have a set XYZ... well, for the tri-chromes, X is zero starting ( it looks like ) the beginning of green anyway, Y is getting good recption and Z is just warming up... for any position in the spectrum, numbers for Y and Z will be unique, and X will be zero anyway...

I guess it depends on how accurate the data is... but the curves in the diagrams ( probably simplified ) looked damn smooth... no kinks where that shade of yellow would match this other one...

Is this other receptor just a help, or is it really giving them a "unique" color? Why don't we have "flat" parts of the spread spectrum that WE can percieve that "hey, you know... that shade is just like this one as far as I can tell, but there is a measurable distance between them, why the hell is that?"

Secret images for mutants and aliens

[AlpineR]

As some others have pointed out, the receptor is sensitive to a wavelength between red and green. But that might not be as boring as it sounds.

Recall how TV screens work. In nature, the light from an object spans a whole range of wavelengths. The profile of this light would be a complex curve (a spectrogram, like some telescopes measure) on which red, green, and blue are just individual points. But our eyes don't sense the entire curve, they just sample it at the red, green, and blue (RGB) wavelengths. A TV takes advantage of our 3-point sampling by producing light at only those points. It doesn't reproduce the whole spectrum, but we trichromats can't tell the difference.

Having a fourth color receptor provides another sampling point. That's bad news for TV manufacturers. A tetrachromat mutant or another species without our eye structure won't be fooled by the RGB image -- they'll sense a color missing just as we would if all the blue phosphors were out. Or, they could see color variation where we see none. A tetrachromat could read "invisible" ink which reflects only at the fourth wavelength. That'd be cool for richer color coding or secret messages.

Mutants of the world unite!

AlpineR

Re:"mutant"

[nastro]

Perhaps the use of the term is for the benefit of certain geno-geeks hoping for X-men type "Mutant Registration", thus getting themselves a list of conveniently female-only potentials. Practical!

Wow...

[Snowfox]

Just think - to them, the world must be a wash of mismatched colors and terrifying ugliness. It's like living in an early WIRED!

They can see more colors?

[lostguy]

Can they see octarine?

Superhero

[oni]

If I were her, I'd get some yellow tights and call myself Rain-Bow

Re:"mutant"

[Kenshin]

Technically anyone with blue eyes is also mutant, since they only came into existance a few hundred years ago. Guess I'm a mutant.

Re:Pigeons & Pentachromats

[thogard]

Not everyones red and green are at the same area. It seems that there are common variations that shift the red or green slightly one way.

One question is that if you have more color vision, is that at the expense of something else?

Most humans that live in cities today don't use their night vision at all. It take 1/2 hr after the last bright exposure for it even to work.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:Clothes matching

[divec]

And by "match" what does she mean? *Exact* same color? [...] Mrs. M. should shut up.

I think it is a bit excessive to criticise a human guinea pig who is merely recounting the experiences she's had during her lifetime. If you want to say "The researcher who works with Mrs M should shut up" then that's different.

your experiment is flawed

[tonylemesmer]

you must start with pure white light for that cloth test to be valid.

Re:Cool...

[paRcat]

yup, you showed 'em.

Typically, it's the less intelligent person who resorts to name-calling.


____

"mutant"

[British]

Is the word "mutant" appropriate here? It sounds like she's one of the characters from X-Men with some special power that the rest of us don't have.

Re:"mutant"

[aenomie]

righto...

according to the strict scientific definition, genetic mutation involves a physical change in DNA structure caused by some external (or possibly randomness) influence. For instance, if you have a bacteria with a genetic sequence of ATTG that gets exposed to UV radiation and is changed to ATTA, you've got a mutant. Just the fact that you have a physical manifestation of a genetic trait that neither of your parents do doesn't make you a mutant; that's just basic genetic dominance/recessiveness

Re:"mutant"

[aenomie]

Keep in mind, that the article stated that in order to find these women, they looked for mothers who's -children- were colorblind, not their fathers. If it was just a case of inheritance, then they should be able to trace these types of traits both ways (descendents and ancestors). A mutation, however, would only go one way (or at least until you hit the generation with the original mutation)

Re:"mutant"

[aenomie]

well, yes it is, because there is some genetic instruction there that triggers the suppression of the 6th digit. if a mutation disrupted that suppression signal, then you'd get your 6 digits. Determining whether something is mutant or not is a relative comparison to the population at large; if "normal" genetic code triggers the suppression of the 6th digit, then lack of that suppression would be considered mutant.

Re:"mutant"

[aenomie]

that's streching the technical definition of mutant a bit. yes, you could use it to say what you are trying to say, but keep in mind that use of the term "mutant" has to be made in reference to a given population. so if you said that you're population is every living organism that ever existed, then yes, we're all mutants, but you haven't really acclompished much by that statement...

Re:"mutant"

[phliar]

daughter has a 50/50 chance of being a pentachromat. ... daughters would be pentachromatic. Now, if we can mutate one blue cone, we can go for hexachromatic kids.

Before people get too carried away.... it's not just enough to alter those genes; the new genes should produce a photo-sensitive pigment that has the spectral response you're looking for. So if the blue-sensitive pigment has a peak sensitivity at 6000nm [just a guess, I don't really know the response of the B pigment] then we need to design a pigment with a peak at 6800nm and then mutate the B pigment gene to make that pigment; and also make sure that the neurological system - the optic nerves and the visual cortex - actually receives that information and can act on it.

Any genetic designers here?

Re:"mutant"

[rapett0]

This is incorrect. 6 fingers are not mutant, in fact 5 are. However during the development process the sixth digit is suppressed, and hence the majority have 5 digits.

Re:"mutant"

[the phantom]

Most mutations are "inferior" to the original species, in that they remove or surpress a capability.

Actually, most mutations are totally irrelevent. There is an average of one mutation in every one billion base pairs (according to my bio. anth. prof. -- this could be more or less) between the parent and offspring. With the huge numbers of base pairs in human DNA, just about every person in the world could be considered a mutant.

The thing is, changes in the genome (genetic information) do not mean changes in the physical appearance or abilities of the mutated individual. In fact, many of the proteins that DNA codes for can be created with multiple sequences of DNA. Thus, one change from A to T in the DNA of an individual may have no effect at all.

This doesn't mean that there are not mutations that have morphological or functional differences, just that most mutations have no effect at all. Thus, they are neither good nor bad -- just there.


----------

Re:"mutant"

[WowTIP]

And we'll hopefully keep on evolving. Very possibly, in 100,000 years or so, we'll all be tetrachromats (and not have appendixes anymore ;). It's natural selection really. If the (mutated) genetic trait of tetrachromats is proven to be superior, it will propagate throughout the human species, resulting in people with better vision.

Is there any natural selection at all in western civilization nowadays? Since most people live until they are at least 70 years old, isn't the natural selection completely shut down?

There isn't that many things that give you any better chance of survival/spreading your genes.

Maybe good looks and social competence. Then people will become more good looking and very nice. The future looks bright. :)

--

"I'm surfin the dead zone

Re:"mutant"

[Grahf666]

And we'll hopefully keep on evolving. Very possibly, in 100,000 years or so, we'll all be tetrachromats (and not have appendixes anymore ;). It's natural selection really. If the (mutated) genetic trait of tetrachromats is proven to be superior, it will propagate throughout the human species, resulting in people with better vision.

What would be fascinating would be to put one of these possible tetrochromats in front of a 32 bit image, and a 48 bit version of the same picture (48 bit or higher monitors do exist, right, we just don't have any need for them?), and see if she could notice the difference. Although, that may not make a difference.

32 bit color, RGBA =
8 bits red
8 bits green
8 bits blue
8 bits alpha

The trichromatic concept of 48 bit color would be, still RGBA =
12 bits red
12 bits green
12 bits blue
12 bits alpha

Although, as I understood it, tetrachromatics don't see more depth of color, they see an extra element of color. Thus it would be RGBA+unknown red/green combo color =
8 bits red
8 bits green
8 bits blue
8 bits alpha
8 bits new color

Wait that's only 40 bits. 12 bits per red, green, etc is 60... Maybe it doesn't work out that way anyway.

Re:"mutant"

[dr_eaerth]

Not as long as women keep dating Assholes it doesn't. We will start evolving into a more intelligent and nicer species aproximately one generation after women decide not to put up with stupid assholes just because they're good looking or have money.

I don't pretend to understand women's little quirks.
Just one thing I know for sure,
Chicks dig jerks.
-- Bill Hicks

--

Re:"mutant"

[pugugly]

Not as long as women keep dating Assholes it doesn't. We will start evolving into a more intelligent and nicer species aproximately one generation after women decide not to put up with stupid assholes just because they're good looking or have money. Until then the human race is doomed - sigh.

This has been a test of the Slashdot Broadcast Network . . .

Re:"mutant"

[pugugly]

I say this of course as someone who is neither goodlooking, nor do I have money - Grin

This has been a test of the Slashdot Broadcast Network . . .

Re:"mutant"

[Keighvin]

Not necessarily - remember that the tetrachromacy relies on X chromosome inactivation. Only if those 2 X chromosomes recombined exactly to pass on the trait would it be present in the daughter. The likeliness of this occurance drops steeply. With the colorblind father you're more likely to produce another tetrachromat, if at all. Too much unpredictability in the recombinance of the DNA to make statistics, though.

Re:"mutant"

[Rentar]

We can't define by colour? Reminds me of HG2G:

"Where are we?"
"Something green."
"What is this?"
"Something blue."
"Shapes, I need shapes!"

(One Geek-Point for anyone who knows the next line ;-)

Re:"mutant"

[Ratteau]

Technically, a mutant is an organism that has characteristics that neither of its parents had.

No, that is too based on the physical being, a mutated gene doesnt have to manifest itself into any visible difference. Nor does the fact that you have different color eyes from both your parents mean that you are a mutant. Recessive genes would be an example: to give you blue eyes, for example (to borrow from another post I just saw). Neither parent has blue eyes, but the way their DNA split and combined to form yours can give you a trait that neither of them have.

Re:"mutant"

[Kierthos]

Technically, a mutant is an organism that has characteristics that neither of its parents had. Only in Marvel comics does mutant = super-powers.

So if someone has tetrachromatic cones in their eyes, and that person's mother didn't have it (from the article, all tetrachromatics are female), then that person would be a mutant. If the mother was a tetrachromatic, then that person would not be a mutant.

Kierthos

Re:"mutant"

[HD Webdev]

Is there any natural selection at all in western civilization nowadays? Since most people live until they are at least 70 years old, isn't the natural selection completely shut down

Not by much at all.

What does matter is how many children you have that live long enough to have their own, how many children they have, and how early they start breeding.

For example, intelligent people tend to have less children per couple than the rest of the population. Not only that, their generations tend to be spread farther apart.

Re:"mutant"

[The Blackrat]

Webster.com's definition.... "a relatively permanent change in hereditary material involving either a physical change in chromosome relations or a biochemical change in the codons that make up genes"

Re:"mutant"

[Jedi Alec]

Depends on how you define "mutant". Basically we're all mutants, considering the amount of evolution the human race has gone through. We evoluate all the time. But in the more popular term of the word mutant, yes she is one. It's a little less spectacualr than the X-Men though...

Re:"mutant"

[Chuck Chunder]

So if someone has tetrachromatic cones in their eyes, and that person's mother didn't have it (from the article, all tetrachromatics are female), then that person would be a mutant. If the mother was a tetrachromatic, then that person would not be a mutant.

Surely it comes down to genetics, not whether a particular attribute physically manifests itself in her parents.

If her genetic sequence is directly derived from her parents then she isn't a mutant, even though she exhibits an attribute that neither of her parents had as individuals.

For someone to be a mutant, their genetic make up must be somehow altered from what we would expect it to be.

Probably

Re:"mutant"

[remande]

Yes, the word "mutant" makes sense, in both the real and Marvel senses of the world.

In the Real World, a mutant is someone or something with a mutation, which is nothing more than accidental gene-tampering. People with XXY as their 23rd chromosome are mutants. People with six fingers on one hand("my name is Inigo Montoya...") are mutants.

Most mutations are "inferior" to the original species, in that they remove or surpress a capability. This woman is an exception; her mutation appears to give her a superhuman ability: a peculiar type of vision. In the comics, mutants are always the superior variety, with superhuman capabilities. While I don't imagine she is qualified to put on a silly costume and slam evil, she does have a special power.

Re:"mutant"

[jovlinger]

The article didn't mention this, but does this mean she's losing resolution to gain color, or does the resoltion stay the same?

As a visualisation aid, imagine an LCD with 3 subpixels. Assuming that the pixels didn't shrink, if we went and added a 4th subpixel, we would have to sacrifice resolution when doing so.

Re:"mutant"

[fiziko]

If the mother was a tetrachromatic, then that person would not be a mutant.

Unless the child is a pentachromat. Picture this: mother is a tetra chromat, say, with one normal X chromosome and one with genes for two slightly different red cones. If the father is colorblind with two slightly different green cones, the daughter has a 50/50 chance of being a pentachromat. Find a (rare) colour-blind mother with two slightly different red chromosomes on each X chromosome, and you can (almost) guarantee all daughters would be pentachromatic. Now, if we can mutate one blue cone, we can go for hexachromatic kids.

Re:"mutant"

[-Harlequin-]

but does this mean she's losing resolution to gain color, or does the resoltion stay the same?

No, the resolution is really the department of the rods - that's where you get most of the image defintiion, the extra cones just means the colours are painted into that image with a cruder brush, which, if you've mess around with image channels, you'll find makes virtually no perceptual difference. (It's quite weird actually - we can't define by colour to save our lives :)

An example that is probably due to the same phenomina - put green text on a red background, and adjust the tone such that there is no tone-difference between the colours (ie your rods see a flat grey - no text at all) then try to read the text using just your cones. You can do it, but your eyes will totally bug out :-)

Maybe

[omarius]

If 3dFX had built that into voodoo5 instead of that stupid antialiasing crap they'd still be in business full force... ;)

-Omar

Re:Maybe

[pugugly]

Well of course they don't - The Graphics are all screwed up - [G]

This has been a test of the Slashdot Broadcast Network . . .

Re:well.........really

[the italian]

i am going to rape your mother.

Re:Clothes matching

[aenomie]

Better yet, shine a red light in one eye but not the other for a minute then look at the same object one eye at a time. Is that object simultaneously 2 shades of the same color?

that's not subjectiveness, that's just fucking with the optical mechanisms that make you're eyeballs work...

Re:Another blow to the male eog

[gotan]

But then at least we have a good excuse :-)

Re:Photoreceptors... still don't get it...

[Cuthalion]

Let's reduce this to a simpler case for purposes of example.

You have two sensors, one of which detects 100 hz signals, the other of which detects 200 hz signals. If you have a signal between the two (say, 141.2 hz) you will see some reaction from each of the two sensors. The ratio of these will allow you to guess what frequency it is. However what if the signal is NOT actually 141.2 hz, but the sum of a 100 hz signal and a 200 hz signal? You can't tell the difference, without adding another sensor.

If you are colorblind, you won't see holes in the spectrum, the levels that your brain DOES recieve will be continuous, and not 'flat', but you will lose some detail of the true nature of the signal.

Re:Still no hope for drivers....

[VFVTHUNTER]

Huh? I may be completely stoned or something, but I thought the SUN produced ultraviolet. So at night, there's not much of it around. That's why night vision goggles use infrared, at the other end of the visible spectrum, which is produced when things give off heat. Since UV heats during the day, and they cool at different rates at night, you can see the infrared given off, particularly the edges between different-cooling objects. I must really suck at electromagnetics or something.

By the way, if I had mod points, I would mod you way down. The sexist comment about women driving is probably the main reason chicks don't frequent /.

A new color

[StrawberryFrog]

> An extra photopigment wouldn't invent new colors

Actually it would. The primary colours Red, Green and Blue are artifacts of the standard human pereceptual system. All the exists phyically is intesities and wavelengths. A fourth photopigment impies a fourth primary colour. This means a whole bunch of new secondary colours.

> it would just more of the spectrum perceptible

Correct, it would make more of the spectrum perceptible, in the same way that a normally sighted person has "more of the spectrum perceptible" than, for instance, my father, who couldn't find red golf tees on a green lawn.

Re:A new color

[StrawberryFrog]

> But it wouldnt be a "new" color. The color has always been there, we just haven't been able to detect it.

What makes you think that colours are "there" at all? We can 'detect' the wavelength and intenstity of light accurately using our electronic equipment. The concept of seeing a fourth primary colour, is however, new to most of us.

> like scientists discovering neutrons and protons and claiming they were new. Not new, but simply detected.

Not a valid analogy. It's not a discovery of any new colour or kind of light. Just a discovery of new human perceptual ability.

We can measure light intensities and wavelengths with great accuracy. Looking at numbers or even a graph and realising that they represent light, that when seen by the human eye, appears to be a particular shade of green, does not give you the *experience* of green. That's all that 'green' is - an experience. The electomagentic spectrum, leaving aside quantum affects, is continious. Part of it causes us to experience green.

Now the tetrachomat human(or a bird, which are tetrachomats) gets the same light as the rest of us, but *experiences* it in a different, more complex way.

Perhaps I should have said "that - which - we - have - no-concept - and - therefor - no - word" but "new" was shorter.

Re:A new color

[StrawberryFrog]

> But it wouldnt be a "new" color

Ooops, my first responsie is incomplete.

If there are tetrachromats now, then there have most likely have been a few of them, a low and constant percentage of the female population, throughout history, and indeed through recent human evolution (and perhaps not-so-recent). Who knows, maybe there are colour blind(Dichromat) and tetrachomat chimps.

So in this sense it's not a few colour at all - some people could see it all along.

Re:A new color

[Nutt]

But it wouldnt be a "new" color. The color has always been there, we just haven't been able to detect it. It's like scientists discovering neutrons and protons and claiming they were new. Not new, but simply detected.

Colour Blind

[rossz]

I'm colour blind, properly known as Colour Deficiency Syndrome. I always make sure I had a woman with me when I shopped for clothes. I learned this the hard way after been told exactly how much my clothes clashed.

But it really sucked to be in my twenties and shopping for clothes with my mom! I'm married now, so my wife picks out my clothes. I do suspect, however, that she is purposely dressing me like a geek so that I won't attract other women.

Re:We already knew this

[warpSpeed]

This could spawn a whole new sociologic phenomenon, women will be able to gage mens' "availiability" by the "matchingness" of his cloths.

Not-matching (single)
Very-Matching (has girlfirend)
Semi-Matching (married, but insists on wearing same flannel shirt over and over again)

~Sean (yeah, the color blind one)

Re:Between Red and Green!?!?!?

[warpSpeed]

Seeing InfraRed would be more useful...

~Sean

Re:We already knew this

[alprazolam]

with brand names and stuff, it would be a hip new line of dkny or something, uglier clothes would become more expensive than better looking stuff.

Re:So why do women ask men, "Does this match that?

[alprazolam]

is infrared a color or just a wavelength?

Re:So why do women ask men, "Does this match that?

[alprazolam]

you make two opposing statements. if it's a wavelength we can't see, is it still a color? i don't think it is, according to dictionaries.

Re:We already knew this

[alprazolam]

no it's a color too. like camel is a color.

mass media nonsense science

[andyschm]

yet again mass media mangles science beyond comprehension.

thanks for an article that basically said nothing. Not only was the headline an incorrect assumption (kind of like 'bush is president') but it also failed to really explain what tetracolor really is - whatever it really is, its definately not an 'extra primary color'.

Re:Color as subjective experience

[CConkle]

I'm the same way. Bad TVs, speakers, random electronics, a bunch of stuff like that. Bugs the hell out of me. I appear to obsessively turn off TVs... when people, for instance, turn the VCR and then walk off (CRT is still active!) the little noise, even on new TVs, bugs all hell out of me. It'd be interesting to find out the frequencies involved, etc.

Re:The story reports only of the possibility

[Dr.Doom]

When is slashdot going get a science editor?

Doctor Doom

Guys can have tetrachromat vision!

[Bacteriophage]

The scientists are wrong in saying that only women can have tetrachromat vision. This is because some males have two X chromosomes and one Y chromosome (genotype XXY), a condition known as Kleinfelter Syndrome. Saying that tetrachromat vision is only possible in females is thus simply wrong considering their explanation.

"There are no shortcuts to any place worth going."

gnarlier qualia

[townmouse]

(Warning: this post contains 3 puns in decreasing order of wit.)

>...we can never truly know that the actual experience of that colour is the same for another person. We just have to assume...

Different people claim to regard the same colour as pleasant or distasteful; why disbelieve them? Why assume Senator McCarthy had the same experience as Josef Stalin on seeing the colour red? Surely their experiences were coloured by their convictions. I expect McCarthy saw red when he saw red.

Do you have the same experience when you see a red tomato, a red banana, a red traffic light, a pool of blood? I don't. Even if a colour recurs in exactly the same context (say the dull blue-green of the default Windows desktop), you'll feel differently about it. However much you first liked or disliked that colour, after continued exposure you will begin to feel jaded.

In languages with only three colour words, these invariably denote what we call black, white and red. Differences arise when others are added, but people are perfectly aware these are only terminological. Someone who considers turquoise to be blue and jade to be green is well aware that they are very similar, much more similar than indigo and lime.

Re:IR and UV in other creatures

[townmouse]

>The weirdest one was an undersea critter equipped with a rotating polarising filter and a sweeping rainbow colour filter over each eye.

That was a mantis shrimp (can't remember the formal name). They're also notable for their weaponry - very fast mantislike spearing or bashing appendages.

Re:Pigeons & Pentachromats

[townmouse]

The latest common ancestor of all bony vertebrates must have had at least 4 photosensitive pigments. Most vertebrates have 4 pigments sensitive to bright light. Most mammals have 2, but primates have 3 (plus a rod pigment for dim light).

Mickey Rowe, an expert on the evolution of colour vision, wrote this post to his dinosaur mailing list and this talk.origins post on the subject. The latter includes this interesting observation:

It should also be noted that many humans carry more than one copy of the middle wavelength-sensitive cone opsin. As this is grist for the evolution of color vision mill, we're literally ripe for the addition of a fourth cone class. (This probably won't happen, though, because people with a fourth cone class will be constantly trying to readjust the color on television sets. As a result of that such people will be highly selected against in bars the world over :-)

This means that engineering tetrachromatism would be easier than expected.

Re:New colors in vision

[townmouse]

It would have to be far-red (close to the longest frequencies we can see already). Longer millimetre waves would be much more informative, because warm objects like mammals emit them, and they pass through substances like masonry while being blocked by metal. Unfortunately, if you had mm-sensitive cones, your own emissions would blind you to anything else.

I believe glass blocks far-red, as well as ultraviolet.

Octave?

[townmouse]

Octave? Surely it would be more appropriate to use a chromatic scale?

Re:Is this why...

[John_Prophet]

Is this why my girlfriend always asks incredulously, "You're not wearing THAT, are you?" when we go out on a date?

Not at all. You're confusing tetrachromats with bad taste. Nobody needs an extra color sense (well, besides you) to know that plaid and polka dots do not a sophisticate make.


-The Reverend (I am not a Nazi nor a Troll)

Re:Clothes matching

[wljones]

I have known for a long time that I cannot distinguish yellow and blue very well. It is not a handicap in daily living, just a nuisance. Other people distinguish color differences better than I do, and those that work for commercial sewing thread distributors are awesome. It is not a reason to tell them to shut up, or to belittle them, which merely marks the speaker as a loser, and a handicapped one at that. As for four-color vision, tell your local sewing thread distributor about it. The distributor will actively search out these women, and do whatever is necessary to add them to the staff.

Re:Pigeons & Pentachromats

[TwistedGreen]

I've wondered this as well. Questions that cannot be answered are always fun.

If everything is merely created by oneself and if all just a wild fantasy, why am I writing this? To whom am I replying? What if I get a response? Will this response be of my own creation, or will another concious being actually respond? What the hell is going on?

I'd like to point you to this related The Parking Lot is Full comic strip, originally created March 18, 2000:

http://www.plif.com/archive/wc221.gif

...but there have to be SOME constants in my universe! Or maybe these constants are defined by me. Hmm...

...ow.

----

I thought the thirties...

[kevin805]

Every movie I've seen from before the 30s, everyone had grey eyes. Blue eyes seemed to pop up shortly after that.

I doubt a few hundred years. I don't think that's long enough to spread. Since blue eyes are common in scandinavia, ireland, and some places in eastern europe, I would guess at least a few thousand years. It seems to be correlated with skin tone also, so I doubt it's a separate mutation. I don't think you'd call someone who's a child of a mutant a mutant themself. Doesn't mutant generally mean first of the line?

On a related note, my eyes are different colors: my left is blue, my right half a slightly darker blue, half brown. I doubt it's genetic, probably just developmental effect (my genes are probably for light brown eyes, but lots of babies are born with blue eyes that change).

Re:I thought the thirties...

[mangu]

Every movie I've seen from before the 30s, everyone had grey eyes. Blue eyes seemed to pop up shortly after that

No, it was something to do with chemical pollution. You see, early photographic film released an extremely toxic by-product in its manufacture, so everything seemed to be colored in different shades of gray at the time, including human eyes. Later, they perfected the process by filtering out the color-destroying chemicals and colors came back to the world. If you look at paintings from before the invention of photographic film, you'll see that they had colors then.

Re:Yes it is the exact term you would use.

[Amokscience]

I wouldn't call it a 'good' mutation. It would seemingly result in more color blind males.

Re:Inheriting desirable traits

[phliar]

Just think how handy it would be to have a tail, when you're trying to solder something. One hand for soldering iron, one hand for solder, one tail to hold it all steady. Youch! But not likely a reproductive advantage. Just because it's handy doesn't make it necessarily a reproductive advantage.

Remember, natural selection is not the only shaping force! The other big one is sexual selection. If the opposite sex find prehensile tails more desirable, this trait will spread in the population. Just like peacocks' tails.

Unfortunately I don't think it's going to happen.

Re:Even cooler.

[iso]

Seeing letters as being different colors may not be the most exciting thing, but there seem to be so many others, "seeing" sounds, "hearing" textures, and the like, that seem like they'd enrich the world.

this is already possible today with DMT.

- j

Re:Klinefelter's Syndrome

[twjordan]

I doubt you meant it to, but your comment sure sounds a lot like "some other great artist" has to be a man.

What? Men can't see these extra colors? Damn, too bad there aren't any women capable of doing anything out there!

Tony

not trying to be an asshole but you gotta start changing perceptions somewhere.

Re:Just wondering

[lcs-150]

More like special monitors, and video cards to match. Normal pixels are only capable of red green and blue, thus the extra colors aren't represented.

Not fscking fair.

[VC]

Am i the only one who thinks that men are getting stiffed on this deal?

How a tetrachromat can see additional colors

[Ryu2]

The observation that a tetrachromat has the ability to differentiate between colors that, to us, seem matching is well taken.

Specifically, "color" is simply a mapping of a spectral power distribution (SPD) of all the continuous wavelengths across the visible spectrum range. Since there are an infinite number of SPDs, it follows that there are colors which have different SPDs which appear to our trichromatic eyes to have identical colors when they're not. These colors are known as "metamers". The tetrachromatic person would be able to distinguish some metamers -- she would see that they are indeed different.

Mathematically, the color that we (trichromats) perceive can be described with threee values: the integral of the SPD multipled by three different weighing functions to describe the three different types of cones/rods in our eyes. Each is most sensitive at some particular wavelength int he vis. light spectrum.

As an analogy, someone with monochromatic vision can only see luminance -- mathematically speaking, the integral of the SPD (multiplied by some appropriate weighing function), which is just a single scalar value. They wouldn't be able to tell whether say, a color was bright blue (on the upper end of the wavelength spectrum) or darker yellow, since they're all the same "value".

More information can be found here: http://www.cs.brown.edu/exploratory/research/apple ts/appletDescriptions/metamers/home.html

Re:Tetrachromat poetry

[AndyL]

Yes, but "blue" does not rhyme with "hues".

IR and UV in other creatures

[chainsaw1]

Technically, I believe the answer is Yes-No to both. Snakes (though not all) are the obvious choice for IR vision with their heat pits under their eyes (commonly mistaken for nostrils). Deer can see in the UV spectrum above what humans can percieve, but not "true" X-rays. I don't think anything can percieve a true x-ray wavelength due to the damage such high energy photons cause living tissue. Many hunting vests use low UV reflective dyes. I think this is why those bright orange vests don't attract attention to game. They are out the game's color wavelength range and are tuned to stay that way while still being bright to other humans for saftey reasons.

Re:IR and UV in other creatures

[Blancmange]

chainsaw1:

Snakes (though not all) are the obvious choice for IR vision with their heat pits under their eyes (commonly mistaken for nostrils). Deer can see in the UV spectrum above what humans can percieve...

An excellent BBC TV programme, Supersenses featured a goldfish. Goldfish can see IR, UV and the wavelengths in between, though I don't recall any mention of the number of kinds of photopigments goldfish eyes have. The implication that the goldfish was more suited to the role of security than the human security guard presented was a bit of a giggle.

The programme also featured creatures with many other kinds of vision systems. The weirdest one was an undersea critter equipped with a rotating polarising filter and a sweeping rainbow colour filter over each eye.

Re:IR and UV in other creatures

[cronik]

You would have the same effect as can be supplied with ir-vis-uv goggles. that is, you just crunch the middle and add the extra bits in. uv becomes v v becomes b, so on and so forth. It would be strange the things that you would suddenly be able to see. But that is no diffrent then strapping on a pair of IR goggles.

Re:IR and UV in other creatures

[sconeu]

I've often wondered about IR and UV vision since my days as a D&D'er 20 years ago... If you could see IR and/or UV, how would you perceive them? Would you see "heat trails", or would you simply see extra (undescribable to normal humans) colors?

Re:Pigeons & Pentachromats

[Rogain]

I use my night vision, but then again I am a burglar.

even more...

[systmc]

My babysitter actually *did* have a whole extra eye in the back of her head. Talk about freaky!

Re:Between Red and Green!?!?!?

[erinelf]

People who have had cataract surgery haven't had their corneas removed, but their lenses. There is increased sensitivity to UV if you've had the lenses removed, but that just means you need to be extra careful to wear sunglasses, not that you have super-perceptive vision.

Maybe she can see the Invisible Boy?

[Cable]

Maybe the invisible Boy turns into that fourth color that most of us can't see? :)

But she would get her *** kicked by "The Spleen". ;)

Don't assume that DNA would dictate

[Jart]

I mean, the social meme might easily override the genetic one. Like imposing right handedness on lefties. One might be omnicient but not-omnicognizant. Blinded by thoughts. How do you know how blind/unblind you are?

A Dose of Critical Thought

[superyooser]

I can't believe everybody here is buying into this Darwinism philosophy. What ever happened to critical thinking? This whole thread is based on absurd premises, yet no one is even questioning the veracity of biological macroevolution (evolution from one species to another).

Firstly, the implicit foundation of evolution is spontaneous generation, which was disproven by Louis Pasteur in the 1880s and has been disproven by many scientists since. Secondly, evolutionism violates the Second Law of Thermodynamics. Thirdly, there are zero fossils of transitional (between species) organisms.

The Piltdown Man was a hoax played by a student on his professor. (Of course, the Darwinist faction of scientists were convinced of its authenticity and erroneously announced to the world that it was real. They were all putty in the prankster's hands.) All the other sub-human "species" are concoctions assembled by eager Darwinist disciples ready to believe anything that fits the evolutionist template. These zealots find a couple of teeth here, an ape jawbone there, and claim to have discovered a whole damn species! They are forcing together a few pieces from similar jigsaw puzzles and: 1) declaring that they belong to the same puzzle, and then 2) extrapolating the remaining 99% of the puzzle based on preconceived beliefs about what it's supposed to look like.

Evolutionism has NO foundation whatsoever. Technically speaking, evolution does not even qualify to be considered a "scientific theory" because:

nobody has been able to produce life from non-living matter under any circumstances in the laboratory, and

nobody has ever observed or been able to induce macroevolution

It exists solely as a way to escape moral responsibility. Darwinism enabled Hitler to justify the torture and slaughter of 6 million Jews (+ 5 million others)... because Jews are just mutated protozoa, right? If you doubt Darwin's influence, read Hitler's Mein Kampf. Also, Josef Stalin killed over 50 million people under the influence of Darwinism and Marxism.

People, THINK about the logically ridiculous and ethically horrific philosophy you are accepting.

Re:New colors in vision

[frogstomper]

I wonder how much longer before someone tries to engineer extra infra-red cones.

ISTR reading that IR eyes based on the same general technology as human eyes, with the same "refresh rate" and "resoulution" even as our night vision, would require eyes about the size of our heads.

Re:Tetrachromat poetry

[frogstomper]

That doesn't even rhyme.

It does... of you have tetrachromatic hearing.

Re:How to perceive

[scotch]

And the alien was invisible (with cloaking device) - hand your believability hat on that.

I Could've Told You This

[Cheshire Cat]

I've always known that women were mutants! :)

Re:Between Red and Green!?!?!?

[Ser\/o]

Hmmm...I've never had cat surgery, but I can read by black light. I used to have a b.l. over my computer, and would often sit reading, even after the monitor powered down. I never knew this was unusual. Or is it?

Re:Pigeons & Pentachromats

[mbadolato]

>> Perhaps the way I perceive blue in my mind looks just like the red that you perceive in your mind

This theory would help explain the clothing old men wear when golfing. =)

Re:Nit Pick Alert

[311Stylee]

yeah, this article seemed slightly hokey... the author confused the terms trichromat and tetrachromat at least once....

and, what happens if, say you have a receptor type for each integer wavelength?

and what is this shite about color blind people having a hard time surfing the web? many people with fully working color vision can't even figure it out... try buying tickets from ticketmaster.com if you don't believe me!


C:\>ls
bad command or file name
C:\>uptime

Re:far red vision

[311Stylee]

hey, neat! i can see it too... extremely faint though. using averted vision worked the best, that is not looking directly at the led, as your rods (which are grouped more around the edges than in the center of your eye) are more efficient at picking up light.

yeah, i agree that this light is probably spillover from the intended electromagnetic output.




C:\>ls
bad command or file name
C:\>uptime

Re:We already knew this

[SmokeSerpent]

Oh no, you should try shopping with my wife.

"Here's a black one..."
"No, that's a different black."
"Wha...?"
"Just get your credit cards ready and let me handle this."

You can already change your color vision

[NearlyHeadless]

If you wear a filter in front of one eye, you can detect more colors. Color blind men can already get contact lenses that allow them to see red.

There's no reason why us trichromats couldn't do the same thing to see four colors.

did you see this documentary?

[SethJohnson]

Pimps Up, Ho's Down!

Same as you, but you got a female pimp.

Seth

Why we don't see UV

[john@iastate.edu]

UV is filtered by the cornea and lens.

In smaller animals (smaller eyes), this effect is less pronounced (e.g. bees see UV).

I suppose it would be possible to see UV with an artifical cornea/lens designed not to filter UV -- since the range of the blue cones extends will into the UV wavelengths -- but who knows what your brain would do with the info...

Re:Why we don't see UV

[Kaki Nix Sain]

I seem to recall reading that some people with plastic corneas have been sensitive to the UV part of the spectrum. But I can't think of where i read this or if it was trustworthy. Furthermore, a lazy search or two on google turned up nothing along this line. So I recommend a grain of salt with my fuzzy memory. But if anyone has heard something similar I'd love to know.

How do you explain sight to the blind man?

[wunderhorn1]

This whole thing reminds me of Flatland, by Edwin Abbot©

It absolutely blows my mind how there are ideas/qualities completely beyond comprehension© Like higher dimensions, ultrasonic/subsonic sounds, ultraviolet/infrared vision©
We can experience sounds beyond our hearing and colors beyond our vision by shifting them back into the human-accessable spectral range, so maybe there is a way to "dither" ¥? a tetrachromatic image down to an average-joe trichromatic one©

But it would never be the same as actually being able to experience it©


-the wunderhorn
#define OH_YES_INDEED 1

Well

[Galvatron]

Presumably if they can engineer female children to se tetrachromatically, it should be equally easy to engineer male children to not be color blind.

She just has to make sure to marry a man rich enough to afford the engineering...

Squant

[loosenut]

Scientists are already developing new monitors for tetrachromats.

Re:Just wondering

[ebh]

For that matter, would we each perceive better graphics if we could get monitors whose phosphors exactly matched the colors of our retinas (and then tweaked standard RGB signals to match)?

As they imply in the article, you're not going to have a significantly larger color space if the fourth color you see is close to one of the other three.

What I want is an Epson Stylus Photo Eye that has six colors...

Better yet, how about user-definable pigments? Tired of everything looking red under that neon in the club? Ever wanted to help Grandma make green and purple polyester go together?

Potential Soldiers?

[LordSaxman]

Would an improved ability to discern color make these women better hunters or soldiers? Seems like a possibility to me if tracking is involved.

Re:propogating into the general population - doubt

[The Red One]

If I understand genetics correctly, genes become more common if the people who possess the genes have more children. Thus, evolution in humans will now favour whoever produces the most offspring.

Considering that anecdotal evidence suggests less-educated people generally have more offspring than more-educated professionals (who are busy with their career), evolution will progress to produce less intelligent humans. NOTE: This is of course a gross generalisation, education has more to do with socio-economic conditions than genetic intelligence - and there is also the fact that we do not know if intelligence is affected by genetics at all.

Another observation is that the genes that produce good programmers will die out completely, as everybody knows that hackers have a hard time finding female companions ;-)

Re:Pigeons & Pentachromats

[spiro_killglance]

Actually Quantum Mechanic only has discrete posible wavelength for bound systems. Light is a free wave and can have any wavelength in a continum of values.

Squant

[Rev. DOG.]

Well, I already KNEW about the fourth color, Squant... how about some NEW news?
---

Pigeons have Red, Green, Blue /and/ Violet

[mtDNA]

In addition to pigments similar to the Red, Green, and Blue that people have, birds have a Violet absorbing pigment. Some birds can even see in the UV range.

In addition, the pigments have evolved this state in the long term, and the four pigments are very different from one another. The article about tetrochromat women says that their vision is probably the same as the rest of us except in extremely rare cases because the fourth pigment is almost identical to either the blue or the red pigment they already have.

Re:Pigeons & Pentachromats

[nojomofo]

Color is just a function of wavelength, and there is obviously an infinite number of discreet wavelengths within the visible color spectrum.

I could be wrong (and I'm sure somebody will let me know if I am), but Quantum Mechanics dictates that there are a finite number of discrete wavelengths within the visible spectrum, thus a finite (though very very large) number of colors within it.

exactly right.

[enmity.]

most night photography books tell you to treat moonlight as if it were sunlight, because it is; it's just sunlight bouncing off a big gray rock. the only correction you usually have to make is to bump the lens down a stop or two to make up for the fact that the moon doesn't light the whole sky.

enmity

I found the DIMPLED CHAD finder

[lordmage]

This woman can be used by the people to find the intent of the voter. Of course it would take 6 years to go through all the ballots!! By that time Clinton would have finally grown tired of it.

Re:Websafe colors?

[Tuzanor]

nya...ever see a chick type in ICQ? text ain't just black and white anymore :-/

Re:Pigeons & Pentachromats

[Chromium_One]

I could be wrong (and I'm sure somebody will let me know if I am), but Quantum Mechanics dictates that there are a finite number of discrete wavelengths within the visible spectrum, thus a finite (though very very large) number of colors within it.

You are correct sir nojomofo. But recall that (as said in a previous post) there is a complex waveform to light reflected, covering many frequencies. We get a sampling of this. Get enough variation in the sampling, combined with the fact that the granularity in changes of frequency (stepping space between quanta) is pretty small... number of possible colors might as well be infinite.

Re:Cool...

[beat.bolli]

Well, I'm no longer a young Creationist, but anyway:
I think what's described in the article is *not* a mutation, since the possibility to be a tetrachromat is latent in every female. They all have two X chromosomes with potentially non-matching green and red color genes, after all. In fact, even pentachromats would not be mutants (one slightly off green plus one slightly off red...)

RGBA??

[MrScience]

So, like, she can see transparencies everywhere? Heck, not even IE can do that.

Re:Klinefelter's Syndrome

[Leven Valera]

So, if a female tetrachromat passes the gene to a Klinefelter child, and that man fathers a son, could the son be a "normal" tetrachromat male?

No, he would be the Kwisach Haderach! (sp)

Re:We already knew this

[mrfiddlehead]

I suspect that the forth colour axis must be necessary to see dust and that all xx's are mutated in this manner.

That would explain the monthly dusting fit that mrsfiddlehead throws.

Re:We already knew this

[kd5biv]

HER: No, that's burgundy. Forget it. Just give me my cream sweater instead.

She doesn't want ecru, or eggshell, or putty? ;-) At least it isn't titanium white ..

Re:The story reports only of the possibility

[anotherone]

Read the story again: only women can be tetrachromatic. Slashdot isn't exactly a chick magnet, ya know..

-------

Re:Even cooler.

[anotherone]

I remember see something about that in an article, I think the vis plugin was Geiss
-------

Re:We already knew this

[rgmoore]

But this claim is just silly. If they can hack people's genes that well, it should be no problem to add an extra photoreceptor or three onto the X chromosome so that men could be tetra-, penta-, hexa-, or whatevera- chromic, too. The author of the quote just lacks sufficient, err, vision.

Dead Ringers

[BadBlood]

Reminds me of the line in Dead Ringers from Jeromy Iron's character. He describes over the phone the peculiar gynecological findings of his love interest Claire (3 ovaries or something like that) to someone he thinks is having an affair w/her and claims at the end, "Basically, what this means is that you're faahhKING A MUTANT!"

Re:Dead Ringers

[mistah_monkey]

She had 3 cervices.... Weird. That was a bizarre movie.
------------------------------------------ ---------------
I bent my wookie

Retina Configuration

[StaticEngine]

Most people are trichromats, with retinas having three kinds of color sensors, called cone photopigments -- those for red, green, and blue.

Isn't this incorrect? I thought that the retina contained two different types of Cones, one of which senses Red/Green and the other of which senses Blue/Yellow, in addition to Rods, which sense brightness. Our retinas are not configured like CRTs, with RGB elements. This is why people suffer from Red/Green color blindness (most common) or Blue/Yellow color blindness (less common) - a defect in that particular type of Cone...

-pjf

Re:Retina Configuration

[Captain Tenille]

Red/Green colorblindness is the genetic one (I should know, as a colorblind individual), and blue/yellow is caused by a disease of some sort. This tetrachromacy is very interesting and all, but I have a hard enough time understanding how normal people see, and swear up and down that my grey shirt is really lime green, or that there was a stop sign behind those branches back there, that I'll never really get this.

Color vision always seemed overrated anyway. I just wear lots of blacks, whites, and blues and have someone come with me when I buy clothes so I don't make any tragic fashion decisions. It can be funny, though, when I go clothes shopping with one of my four colorblind friends (aka, the ColorBlind Posse!)...

-----------------

Re:Even cooler.

[Lispy]

Back in the Sixties they had some substance that tied all your senses together at the same time. It was called LSD! Didnt prove to be very useful, though! Most people got rather confused...;-) It seems filtering some information is important to the human brain to survive in this universe so i consider these mutations as rather dangerous... Lispy

Re:Has Darwinian genetics already ruled against th

[mikeee]

It seems likely to me that tetrachromats would have poorer low-light vision than trichromats, or at least would require more light to see in color as opposed to black-and-white. Anybody understand the physiology well enough to clarify?

Re:Pigeons & Pentachromats

[The-Bus]

Well, consider the fact that there's no way to describe a color without using other colors... That is to say, one can't describe what the color blue looks like to a blind person. By the same token, if everyone had shifted color wheels, there would be no way to prove it. Imagine a conversation between a regular trichromat and a shifted trichromat.

Regular: So, you like Slashdot's colors? (thinking it's a type of green)
Shifted: It's beautiful! A green similar to that you'd find in a pond! (in reality his "green" is an orange... that is, even a pond looks orange to him)

This of course leades to philosophical questions such as "Do we really all see in the same colors?"

Cool...

[Electric Angst]

Hrm... I wonder what a young earth Creationist would say to this...
Someone whould send this link to Jack Chick.
--

missing the point

[jbischof]

You guys are all missing the whole point of our conversation.

We know a lot about how the frequencies we percieve set off certain neurons and receptors but my question had to do with is "my" yellow the same as your "yellow"

How do we know that a colorblind person doesnt see the entire color spectrum, but only at the frequencies that they have receptors for. Understand??? They see a smaller frequency set but maybe they see all the colors we do, within that frequency.

Re:Still no hope for drivers....

[jbischof]

Enhanced night vision with ultraviolet perception would be very beneficial when it's dark and would greatly counteract a woman's inability to drive during the day...

This is exactly the reason why its unheard of, in birds or humans, because it would interfere with our daily vision and therefore be an unwanted quality and genetically eliminated via natural selection.

Re:Has Darwinian genetics already ruled against th

[John Napkintosh]

The amount of light pouring into their eyes is the same; they just have extra reception within the eye. I don't think theother cones would receive less light in the presence of these other recptors.

Perhaps someone with a better understanding of the subject can clarify this.

Re:Wonder if Nitrozac could use this...

[Snaggy]

Heh... alumshubby, you will not believe just how close you are with that!

I mean, if they all survive the Tube Torture Trap that is. :-)

Because she want's your opinion, you dumb oaf

[Snaller]

After all, you are her little honeypie,eh? :)

--

Hm..spy outfits

[Snaller]

I wonder if a pentachromat designer could come up with an outwit that the rest of us couldn't see :)

--

Re:Trying to visualize

[Srin Tuar]

yes, the first color would have a subtly higher saturation, which she would be able to percieve and we would not.

So our yellow would be a much duller yellow to her, and the pure yellow would be somewhat brighter.

yes

[Srin Tuar]

You are very close to correct- however the new colors are probably not that unexpected- we can approximate them by mixing colors that we can see. Imagine that the set of colors is a circle- and the set of colors we can see is an equilateral triangle inside it. There are some points near the outer edge of the circle that we cannot truly see- but we can apporximate them. A person who could see the entire circle would simply have a sharper experiance of color- but would not truly see colors that we cannot imagine.

Re:yes

[Srin Tuar]

what this with greenish red? Its called yellow already. And this new color youre imagining- its like a perception of saturation. Some colors we see are duller than they would - thats all there is to it. compare RGB(255,0,0) to RGB(255,25,25). The first appears sharper to you- you can tell the difference. Thats all it is.

Re:yes

[Kryffpi]

Well no - there must (in a true tetrachromat) be a perception of something that we (trichromats) cannot see.

We could look at a field of what we see as solid color - the tetrachromat could distinguish between different colors that we see as the same.

Therefore they see colors we can't (distinguish from, say a greenish red :)

.Chris

--

Re:Trying to visualize

[Srin Tuar]

not quite. it would definitly be a color you would recognize- just clearer and brighter.

Try to imagine that the set of distinct colors is a circle. The set of mixed colors are the points inside the circle. Our trichromat vision is a triangle of 3 roughly evenly spaced points on this circle. The tetrachrmatic woman has a forth point very close to the green point. The set of exact colors she can see is only a tiny bit more than we can, and the colors she knows are the same as ours. The only difference is that certain yellowish colors to her are clearer/ more dicernable.

Perceiving new 'colors'

[PurpleFloyd]

What I find most interesting about this article is the (possible) idea that humans could learn to see colors not dictated by their genetic code. If this is true, than humans might be able to accomodate some sort of enhanced vision device inside their eyes, once nanotechnology becomes more advanced. Think of the advantages to people in a nuclear power plant, for example, who could detect gamma rays through some sort of miniscule nano-Geiger counter implanted in their eyes and tied into the optic nerve, perhaps. Or for firefighters, say, who could percieve heat as another 'color', and identify the base of a flame. If we really can learn to percieve new colors, this really raises the bar for biomachine enhancements.

But why does it matter?

[PlotFive]

...apart from the biology, which is fascinating. I thought the whole point of the three photo-whatsits was that they respond to the three primary colours, from which ALL other colours can be created. So if your three photo-whatsits are all working properly - ie you're not colour-blind in the normally-accepted sense - then you will be able to see ALL possible colours. This is an analogue system, remember, not digital, so discussions about 32, 48, 64-bit colour depths etc are all off the topic. So what is it that the fourth receptor is supposed to enable, exactly? The ability to see something - a colour ordinary people can't see - that doesn't actually exist because ordindary people can see all possible colours anyway? Duh? Can someone point out what I'm missing here?

Hmmm

[pugugly]

In the range of things that someone will undoubtably call an urban legend, I *have* known of someone whose vision extended past the violet range. A friend of mine knew the gentleman from chemistry (For those counting at home - My friend knew the man personally. Not a friend of a friend that heard of a guy . . . With none of the other indulgences of urban legends, I choose to believe him - Grin) he never knew he was different from anyone else until he was assigned to jot the lines for a spectrascopy (If my terminology is correct) graph - his teacher informed him he was cheating because he jotted down two other lines in the near ultraviolet. After a couple more tests of it, the teacher was forced to conclude that either his vision extended quite a bit into the UV range, or he was better at cheating than he was at catching it - . I only bring this up because (A) I thought this was what this originally referred to before reading the article, and since it's not, (B) does anyone know the term for this mutation? Pug

This has been a test of the Slashdot Broadcast Network . . .

Extra primary color in science fiction

[cbogart]

There's a H. P. Lovecraft story about a meteorite that is a fourth primary color, "The Color Out of Space", printed in Sept '27 Amazing Stories.

"The colour, which resembled some of the bands in the meteor's strange spectrum, was almost impossible to describe; and it was only by analogy that they called it a colour at all."

Mutant female found...

[cheekymonkey_68]

...on slashdot

Proof that enhanced colour vision leads to trolling on /.

Misleading info.

[karlm]

Male Tetrachromats
It's not actually true that males can't be tetrachromats. If a normal X chromosome carries the information for 3 types of cones, and a woman has a mutation in one of the cone genes on one of her X chromosomes, she'll get 4 types of cones.

However, it is also possible for a gene to get duplicated on a chromosome durring miosis. Thus, a male could cary informormation for 4 cones, two of which would be identical. If however, there was then a mutation in one of those, he could be a tetrachromat. This is, however, much less likely than a female tetrachromat.

Infrared Cones
Many posters have brought up the coolness of infrared cones. However, I think they're dreaming of bodyheat-sensitive cones. This would be like trying to look through a glow stick! Your vitreous humor and aqueous humor are at body temperature! Granted their black-body emissivity is probably pretty low, but the inide walls of your eyes probably have fairly high emissivities. (Look up black-body radiation). The isides of your eyes would be very bright.

Karl

I'm a slacker? You're the one who waited until now to just sit arround.

Useless super powers

[jayhawk88]

This kind of reminds me of a Top10 list I saw on some Usenet group way back in the day, Top10 Most Useless Super Powers. Among the list...

The ability to breath hot soup
The ability to tame excited squirrles

Forgot the rest. Anyway, the ability of Enhanced Color Depth Vision seems to fit. I wonder what her secret identity would be? Magenta? Rainbora? Mistress Spectrum?

Re:Color as subjective experience

[mlong]

>low pitch may think differently about a piece of music, or a type of noise, than you or I might.

This reminds me of something. When monitors start to go bad, they get this really high pitched squeal. I can hear it just fine and it irritates the hell out of me. But many other people around me can't hear it. Kindof interesting to see who can and who can't.

Re:Pigeons & Pentachromats

[imagineer_bob]

What I'd like is IR and X-Ray vision!

While X-Ray is pushing it a bit, do any animals have IR vision? After all most photosensitive chemcicals and substances I know of (film, CCDs, etc) have no trouble with IR (and film does quite well with X-Rays).

Re:Lie Detection By Color

[imagineer_bob]

But if there are tetrachromats, or even other kinds of better vision, maybe they CAN see things like this....

And of course we all know that Moms (and teachers) do have eyes in the backs of their heads!

Consider the following...

[cr@ckwhore]

I was very intrigued by this article! I read the entire thing in amazement and it instantly started me thinking about human evolution. I believe that we may be witness to the actual process of evolution, where genetic irregularities prove to be superior to genetic non-irregularities. Such occurances are extremely rare and we are lucky to be in an era where we understand genetics!

An interesting part of the article near the end eluded to the possibilites of utilitzing our genetic technology to control and create tetrachromats. Should tetrachromacy move into society on a larger scale, then we'll have a mixture of superior and less superior human beings existing in society. Such a society could noteably be the first where the species itself is in control of it's evolution! There's a lot to think about, but I think control of our own evolutionary steps would be a marvelous thing, but dangerous too. If only we could evolve the non-physical aspects of human beings, read responsibility and morality, so that we can use such tools successfully without destruction.

We as humans have mastered the building of complex machines. We're beginning to master the complexities of biological machines. I believe that in the future, the possibilities exist for human beings to create extraordinarily complex biological machines, or life itself, which brings the ideas of a "higher being" (god) full circle. After all, we ourselves are complex biological machines.

--cr@ckwhore

UV vision for all!

[Keighvin]

Do you have any links to this information?

Re:So why do women ask men, "Does this match that?

[Valar]

The reason you can't see a lot of colors when it is dark doesn't have to do with the light/dark modifiers, it has to do with the amount of light that must be reflected into the eye in order for certain parts of the eye to work. I can't remember if it was rods or cones that see colors, but whichever it was, that type of cell takes more light to become active than the cells that just see light or dark. Thus, in dim light, things appear to lose color.
+===========================+
|http://mere.2y.net/scoop/ |
|Tome=SCOOP+COOL_CONTENT; |

Exhonerated tailors?

[ziegast]

Perhaps those tailors for the Emperor's new clothes were innocent after all. Our ancestors of lowly tri-color ability couldn't see the fourth color in his wardrobe.

Jump on the stocks now! The Nokia faceplate, Crayola crayon, M&M candy, VW Beetle, and Apple iMac can now come out with another limited edition color for their produts. Sales will soar! Only those with distinguishing taste will be able to figure out it's not greenish red.

Females and their diferences

[howman]

Calico cats are always female too.

funny

[magnum32]

So I guess women are mocking us men when they ask our opinion on how their outfit looks.

Re:Clothes matching

[natenate]

Perhaps you're partially color-blind and they're merely trichromatic?

Re:So why do women ask men, "Does this match that?

[sqlrob]

Not necessarily. That's the way humans work, but that doesn't make it true.

What about some (hypothetical) creature that has nanometer or better resolution, all the way from near 0 to several meters? That's a hell of a lot of colors.

Re:Yes it is the exact term you would use.

[sqlrob]

That's not a mutant.

That's a mosaic (two or more sets of genetically different cells). It's abnormal (statistically. I am not making judgements here) and is not a mutation, except potentially in the mother for the fact that her systems allowed it to happen.

Just when I've cured my inferiority complex...

[ocelotbob]

I'm sending you my shrink bills, Malda!

Just when I've gotten reasonably acceptant of the fact that color schemes that look all right to me offend over half the population, someone discovers people with super-human color vision, who more than likely would spontaneously combust when they come across my lack of color choice.

Although I'd love to have color vision in the infrared spectrum. Mmmm...heat signatures.

Re:Just when I've cured my inferiority complex...

[modified soy protein]

MMMMMM.....sun beam.

We can remake all films/photoes/DVDs

[Yudit]

If mutants will predominate in the future, will they look at our films and phtoes as we look at old black-and-white ones?

I always thought that three color space is a hack. We should really encode the whole color spectrum just like the the audio spectrum for audio. But it needs a little bandwith than audio.

Re:Yes it is the exact term you would use.

[whizzard]

If the 4 color vision is a good mutation, it will hopefully propogate into the general population eventually (well, half of it anyway :)

I'm curious... when this has propogated to a measurable percentage of the female population, will their male offspring have a higher change of being colorblind?

--mdr

Re:Old news...

[talesout]

Well, well you just fi....

Ah hell, never mind. It isn't worth the effort.

Re:Old news...

[talesout]

That wasn't me, if I was going to belittle you I would do it with my account. After all, it's not as if it would be difficult to tear you apart. But I'm not that bored today, and I'm getting ready to start a new project.

If the above AC would have got your name right though, that might have been funny. Personally, I think he or she could have done better though.

Re:Old news...

[talesout]

Thank you for setting me straight. As always, your insightful comments have left me wishing that I could be even remotely as cool as you. Please forgive my lame attempts to aspire to your greatness. Your anger and hostility towards me are obviously justified as I am but a poor, stupid and idiotic person. This should be made obvious by the fact that I post to slashdot at all.

Re:Old news...

[talesout]

Yet your brilliant comment makes it seem as though you also fall prey to the belief that Star Trek (and all of its offspring) are simply documentaries that somehow wandered backwards through time to become 20th century entertainment.

Sorry, gotta go, there's a re-run of Voyager with seven-of-nine running down a corridor*drool*.

Mutants

[Archangel Michael]

They are here, they are dangerous. We must register all mutants. I have even heard of a girl that can pass through walls. What is to keep her from walking into a bank vault and taking the money? Xmen live!

Re:Pigeons & Pentachromats

[SubtleNuance]

Ive often indulged myself in several whims of fancy similar to your zombie idea:

Ive thought that it would be possible that the whole of my perceived world is a construct to give me 'consciences ness'. The planet, the universe, the people around me, everything I 'perceive' could be artificial - that I alone possess conscience and that nothing I 'do' actually has any affect on the world around me (ala matrix i suppose.. but I swear I have been thinking/talking about this before I saw the movie.. really..). Ive often thought that I could very well be a computer program, running in some alien CompSci lab somewhere - how would I know the difference? How does my present existence differ from what we all imagine will be the 'life' of future AI written by humans? This has often been the topic of my giving myself a 'think headache' (Ive also called them brain orgasms...)

Re:Pigeons & Pentachromats

[SubtleNuance]

I love that comic!

What the hell is going on?

I dont know man - I dont know.. its all kinda strange isnt it...

Re:Old news...

[Gondola]

Well, technically, he hasn't done it yet... Wasn't he/won't he be in the 24th century?

not a new color

[Sebastopol]

First off, lots of discussion about this "new color" doesn't sound like what the author intended. An extra photopigment wouldn't invent new colors, it would just more of the spectrum perceptible. For example, I can barely tell the difference between lapis lazuli and indigo, but a woman I used to date could easily. It's not a new color, and it's not a brain bender to conceive of it, it just means that more of the spectrum stands out.

I suspect it would be a similar effect as looking at a bunch of red green squiggles through red lenses, but not needing the lenses. The point is, more data could be encoded using an extended palette. But then again, MS Windows excessive use of color in icons has pretty much thrown that theory out the window.

On another note, the only two examples the author could come up with were: knowing when I child is flushed, and an enhanced accessory matching ability. That ruffled me a bit, but I guess child-rearing and accessorizing are fair female distinguishers.


---

Re:not a new color

[Chris Johnson]

It's the same as any skilled perception, really. The article was _really_ stupid in many ways.

If I wanted to make optimal use of a tetrachromat, I would have her color calibrate my monitor or proof printed stuff, or choose between photographic paper. That sort of thing. Looking at the real world and then looking at some poorer copies of it and deciding which was most accurate.

I wonder if these clever article writers have ever heard of LAB color- or Edwin Land's brilliant experiments synthesising full color from polarized white light and _red_ light? Color is a hell of a lot more mysterious than these people think.

As for the poor wretched colorblind websurfers- *ROFL* yeah, like there's any color-specific interface consistency on the web in the first place! Riiiiight.

Red (?) Herring

[omay]

Is the publication really Red Herring or can't we accurately see its true color? Perhaps it the color "bleen" between blue and green.

Re:Color as subjective experience

[sulli]

Speaking of high pitched squeals, I used to have a Mac "exploding" Powerbook 5300; it squealed whenever you charged the battery. Many people didn't notice it, but I sure did! Similar thing.

Re:plack's quantum principle

[Blancmange]

s0ma:

doesn't this mean that there are finite colors?

You could produce a practically unlimited number of colours even though the number of possible wavelengths is finite (though quite large). Consider each wavelength as a primary colour and mix the rate of which photons of each wavelength are produced to varying degrees.

Cones in human eyes have a finite range of levels they can distinguish, something like 480. I suspect humans can see 110 million colours, nonlinearly spaced.

Re:New colors in vision

[Blancmange]

N man:

IR vision, cool! A few cones for X-ray, like Superman? Wow!!! Why not add radio wavelenghts and UHF so we can listen to radio and TV broadcasts without needing any gadgets? All 5 gazillion cable channels at the same time! Cool! Oh, oh... sensory overload! I can't think anymore... I've turned into an antenna...

You should see The Man With the X-Ray Eyes. He didn't enjoy it very much at all towards the end. He was most upset lying in bed at night, seeing through his closed eyelids, through the upper floors of the building the brilliant stars.

Re:Websafe colors?

[Blancmange]

toolie:

Does this mean that the web safe palette drops from 22 to 2? Just black and white now...

White is hardly safe when monitors come preset with 6500K, 9300K or even 5500K as the colour temperature used to define 'white'.

Inheriting desirable traits

[sbjornda]

If the 4 color vision is a good mutation, it will hopefully propogate into the general population eventually (well, half of it anyway :)

Only if it confers a clear reproductive advantage, so that those with the trait end up having more babies living to reproductive adulthood than those without the trait. I.e., the trait makes them more attractive mates, helps them to hunt for food better, or avoid more fatal risks before reproducing.

Semi-related: Just think how handy it would be to have a tail, when you're trying to solder something. One hand for soldering iron, one hand for solder, one tail to hold it all steady. Youch! But not likely a reproductive advantage. Just because it's handy doesn't make it necessarily a reproductive advantage.

Re:propogating into the general population - doubt

[sbjornda]

This hardly rates a "Troll". Who in their right mind would waste a moderator point that way?

Re:Photoreceptors... still don't get it...

[tricorn]

Look at the slide shows. They show one slide with the spectrum as seen by a dichromat. There are no gaps in it, just yellow at one end and blue at the other

The problem with Red/Green colorblindness is that you have a large area of the spectrum with only one receptor able to sense it. Once it is beyond the range of the blue receptors, you can't tell what shade it is. The slide is marked as yellow on one end, but could just as well have been marked red or green. Depending on which receptor is missing, a constant-level spectrum would look brighter around one particular frequency, but otherwise look the same hue.

A tetrachromat would see the extra primary color between yellow and red or between yellow and green. The other colors would be better defined. So what most of us see as an indistinct shade of greenish yellow, the tetrachromat would see as a distinct shade

A single-frequency light source would look the same to either. What the tetrachromat would be able to do is distinguish between combinations that look the same to a trichromat. In your example, a mixture of red and green (with a bit more of green than red) would look different from something that was actually greenish-yellow (i.e. with a frequency between red and green) that looks to a trichromat exactly the same.

In particular, color prints and color monitors showing real-world images, being tuned for our RGB eyes, would look different for someone with RYGB eyes. What looks very natural to us would look unnatural to them, since the world is made up of many more frequencies than just RGB. The same thing would happen with someone who had a color shift in their sensors, e.g. RYB, but I don't know how common that might be. From the article, it sounds as if offspring of a tetrachromat might be something like that. I've always wanted to see if having a monitor with 5 colors (Red/Yellow/Green/Cyan/Blue) would look more natural to at least some people (I imagine that a continuous-spectrum monitor would be rather difficult to make).

Re:Still no hope for drivers....

[SomeoneGotMyNick]

OK, I copied and pasted the wrong word....

Tetrachromats, not trichromats

Re:Still no hope for drivers....

[SomeoneGotMyNick]

UV light, being a short wavelength, should bend a bit more through the atmosphere and around the earth's curvature. UV in some degree would be present in the post sunset hour(s). Ever look at a 'neon colored' object just after dusk? It still seems to 'glow' in the twilight sky with no visible sun. Also, light gets reflected off the moon at night. UV light may have a higher intensity than the visible light given off by the sun and reflected to earth via the moon

By the way, if I had mod points, I would mod you way down. The sexist comment about women driving is probably the main reason chicks don't frequent /.

(Score: -1, Clueless)
You picked the wrong place to find chicks on the net.

Graphic Designers

[BrightIce]

I guess webpages or color displays designed by tetrachromats would seem perfect to trichromats as the first ones can find error the others can not. This must apply to everything that has to do with colors.

Secret messages!

[maddogsparky]

Just think of the possibilities for messages in backgrounds! I can just picture it-a harassment lawsuit dismissed because nobody but the woman defendant can see the message in the company literature denouncing her sex/race/religion! Secret marketing campaigns!

How about the emperor's new clothes, modern style? Someone buys the latest, greatest, 4-color garment, only nobody but the tetra-colors can see that it is only three colors!

I guess a better question is, how long till we see the first law/lawsuite involving 4-color vision?

How to perceive

[maddogsparky]

In the movie Predator, the alien's point of view was shown in a red-only picture, signifying infrared. If someone could see infrared as a fourth color channel, wouldn't they be unable to see it seperately from normal color vision? I can't consciencely only see blue, for example.

On another note, how about seeing ultra-violet? Lots of insects have it. A lot of flowers that appear very dark or black are brilliant in UV.

Well, that explains things...

[Hacker Cracker]

And here I thought Negativland was pulling my leg with this so-called discovery of the color squant.

Boy, is my face sqaunt!

-- Shamus

This space for rent

Re:Well, that explains things...

[vanillicat]

Is it really a "new" color if trichromats can see it? The way I understood the tetrachromat article, they are able to distinguish between some wavelengths of light that trichromats can't. I don't see how this "new" color is really new at all if trichromats, as well as tetrachromats, are also able to distinguish it as being a different wavelength.

Re:This is interesting to /bots...

[cjhoworth]

Depends on the Linux user . . .

Re:Woman can pee standing up

[pmw57]

Don't worry. Here's the link.
Somehow it has ingrained itself upon my memory, even after many many months.

A Woman's Guide on How to Pee Standing Up
http://www.restrooms.org/standing.html

Re:New colors in vision

[the N man]

IR vision, cool! A few cones for X-ray, like Superman? Wow!!! Why not add radio wavelenghts and UHF so we can listen to radio and TV broadcasts without needing any gadgets? All 5 gazillion cable channels at the same time! Cool! Oh, oh... sensory overload! I can't think anymore... I've turned into an antenna...

--

Re:Cones see Colour

[Kiffer]

If one has an increased number of cones giving better colour vision. does this decrease the number of rods?, and would'nt this make ones night vision less useful? I've heard that birds have much better colour vision than us but that their night vision is very poor. also do men who are colour blind have better night vision or is it just that they have defective cones not less ... ? what about those people with true colour blindness... I wonder do they have good night vision ...

Re:We already knew this

[david duncan scott]

Too bad you're wrong:

khaki \"ka-ke, "ka-\ n [Hindi khaki dust-colored, fr. khak dust, fr. Per] 1 : a light yellowish brown color 2 : a khaki-colored cloth; also : a military uniform of this cloth (c)2000 Zane Publishing, Inc. and Merriam-Webster, Incorporated. All rights reserved.

You're probably thinking of twill.

Re:What happened to the old color model?

[PhunkySchtuff]

Well, there are two basic models for describing colour. for the purpose of this discussion, we'll be ignoring models like YUV and CIELab and the like, and concentrate on the basics.
Colour is no more than light of various wavelengths being picked up by your eyes.
there are two methods we have to get "coloured" light into your eye... either have it reflected off an object, or transmitted through an object.
when dealing with transmitted light, we use the RGB (Red, Green, Blue) colour model. forget everything you learned in school about Red, Yellow and Blue being the primaries, they're wrong.
when dealing with reflected light, we have to use the complimentary colours for Red, Green and Blue... namely Cyan, Magenta and Yellow (and for printing purposes, to decrease ink coverages and improve contrast we add Black [K] to this mix) giving us the CMYK colour model.
human eyes have four types of light sensitive cells in them. one set that are sensitive to Red light, one set sensitive to Green light, one set that react to Blue light [Cone Cells] and one set that are not as sensitive to colour as they are to the presence or absence of light [Rod Cells].
Now, as for RGB not modelling the tange of human colour vision, RGB _monitors_ can't display every colour we can see, however a perfect RGB space can reproduce any colour we can see, bearing in mind that some surfaces _interfere_ with light, such as the wings of a butterfly and appear to be a colour that they are not.
Back to RGB and CMY - When mixing pigments to produce colour, instead of mixing pure light, it's a subtractive colour model. we use, say, cyan pigment to subtract red light from the picture, magenta subtracts green light and yellow subtracts blue light. when mixing light, we use the additive colour model, adding various amounts of red, green or blue light.
the human eye is most sensitive to light in the green areas of the spectrum, and red/green colour blindness is caused by varying ratios of red to green sensitive cone cells. total colour blindness is caused by no cone cells, only rod cells in the eyse, giving this person superior night vision =)
anyway, that's enough, for more info, browse some of the links that have been posted here
-- kai

resolution

[Confound]

you know you're spending too much time in front of a monitor when you start talking about organic vision in terms of resolution. (last summer i caught myself doing it. . . "gee, those leaves are really high res. . . umm... uh, i'm outside. whoops.) confound

Interesting...

[Xardion]

My girlfriend's mother has a rare form of monochromatic color blindness. She can't distinguish any color from another, apart from light or darkness, except for red. It also causes her to go 'snow-blind' during the day, so she wears red-tinted glasses when she goes out.

I hereby patent the bicolor lawsuit

[RedLaggedTeut]

Imagine: someone who is red/green colorblind sues the rest over using 3 colors.

I bet this is possibly in USA.

far red vision

[egm]

Does someone knows about studies about human vision in the far red range? (maybe near infrared range?) Long time ago I discovered that I was able to "see" the LEDs of some remote control devices under very dark conditions and I'm very courious to know if that is common or it's a sort of mutation.

Re:far red vision

[JatTDB]

Not all LEDs give off pure light (all of one wavelength). Especially with cheaper LEDs with not-quite-so-pure stuff used in the construction, it's possible to have other wavelengths coming out.

What a pity!

[BlowCat]

Too bad she is 57. If she were 27 I would marry her :-(((

An additional color channel?

[Cardhore]

So does she need a DVD player with four composite outs?

Re:Color as subjective experience

[BlueJay465]

Turn this around for a second. If a tetrachromat defines a color as being white, like all R+G+B+Q values equalling 100%. If this were the case, what would the rest of us trichromats see?

Re:Klinefelter's Syndrome

[update()]

To clarify this: all individuals with more than one X chromosome undergo inactivation to bring the number of active X chromosomes down to 1 per cell. Normally, women (XX) inactivate 1 chromosome; men (XY) inactivate none. (I assume this is what the "X inactivation is only possible in women" refers to.) However, a Klinefelter (XXY) male also has an inactivated X.

plack's quantum principle

[s0ma]

plack's quantum principle states that any classical wave (light, for example) can only be emitted or absorbed in discrete quanta. a quanta is the indivisible unit of a classical wave.

doesn't this mean that there are finite colors?


#physics i0n

Re:The story reports only of the possibility

[retinaburn]

There have been very few attempts to find Madam Tetrachromat. The one that turned up Mrs. M in England, in 1993, was led by Gabriele Jordan, then at Cambridge University and now at the University of Newcastle. i think she'd be pissed to find out she doesnt exist.

How did this get moderated up

[retinaburn]

The comment is incorrect and can be found to be false in the first paragraph or so. Dr. Jordan hasn't found a tetrachromat but others have ...HURRAY /.

Re:Old news...

[minusthink]

Congratulations cybrog_monkey --

Re:Old news...

[minusthink]

(sorry for the broken post) -- I don't think it is much of a stretch to say that you are the most stupid, ignorant person on these boards. shouldn't you be wanting your MTV? You completely lack tact, wit, and character. Your profanities reflect your empty head and your double digit I.Q. Perhaps you should stop talking now.

Re:Pigeons & Pentachromats

[Actinophrys]

People don't perceive colors in the same way if you consider finer details. That is to say, if you look at the neural pathways activated by a given color, they will be different. That's why the same color can remind different people of different things.

On the other hand, people do perceive colors in the same way if you consider only the grosser details - namely, what color would they call it.

Basically, depending on how you define "perceive the same way", either everyone trivially does or everyone trivially doesn't. The question is ill-defined.

Re:Yes it is the exact term you would use.

[Daath]

Im sure if you looked closely enough, most of us have some sort of genetic mutation in our DNA

I would say that's a pretty safe bet. Human beings, well actually all life on earth, is what it is because of genetic mutation. Genes are pretty "unstable" - This is good and bad, this is why we have things like cancer, but this is also the reason that we are humans. If genes were stable, ie didn't mutate, we would still be amoeba or whatever the basic stuff would be.

We're all mutants, some more so than others! ;-)

Dr. Charles Xavier ...erh, Daath I mean

/me is Confused

[Fatal0E]

So does that mean that these people would or would not be able to read those alleged graphs and tables from that memory guide?
"Me Ted"

Is this why...

[dmatos]

... my girlfriend always asks incredulously, "You're not wearing THAT, are you?" when we go out on a date?

Re:Pigeons & Pentachromats

[corvi42]

This is the famous problemn in philosophy around qualia. We can test the visible spectrum of light in terms of the wavelength and measure any individuals perception of it, but we can never truly know that the actual experience of that colour is the same for another person. We just have to assume based on the fact that we communicate consistently and experience for ourselves consistently that another person has the same experience, but we can never truly know.

The issue is further complicated by cultural definitions of what makes a colour. Not all cultures divide the spectrum into colour groups the way we do. This has nothing to do with any physiological difference or any actual difference in the way that those colours are "experienced", but is a difference in where groups of colours begin and end. We have groupings of red, green, blue, yellow, etc. that we decided as a culture are meaningful groupings for colours - they begin and end at specific points in the spectrum. Some other cultures not only give different names to these groupings, but actually have the borders of them in quite different places. For example two colours that we might think of as different shades of green ( say lime green, and a very blue turquoise colour ) a person from another culture may say are actually two very different colours - as different as red and green are for us. And colours we consider to be very different - purple and red, they might say are very much the same. So how one is brought up in a culture also has a big impact on what you end up thinking about colours, even if the qualia ( the "experience" ) of the colour is the same, and the segment of spectrum is the same.

The issue of the qualia though - what one truly senses and experiences, is made even clearer when you try to imagine what must be experienced by animals who have sense totally other than our own. For example dolphins and bats have the sense of echo-location. We can test their abilities with this, but we simply don't have the neural hardware to process these types of signals and we can't possibly imagine what it must be like. Is it like a sense of hearing? Is it like a sense of sight? Is it like a strong intuition? We really have no way of knowing.

There have been interesting experiments done with people who are blind not because of a failing in their eyes or optical nerves as is normally the case, but because the optical center of their brains is significantly damaged for whatever reason. A blind person cannot see, but they knows that they cannot see. These people are interesting because they don't know that they cannot see - they simply have no concept of what seeing is like - because they don't have any working optical centre to their brain which might give them even the slightest intuition about what sight is like. Very often they will maintain that they can see despite huge evidence that they cannot - that evidence is meaningless to them, because they have no way of correlating it to what we consider to be sight. For example they might tell you you are wearing a green tie, but you are not wearing a tie at all - and they furiously maintain that they know you are, they can see it. Perhaps its all just imagination on their part, but because they don't have the optical hardware to understand the rudiments of sight, they don't realize that there is any difference between such an imaginated "image" ( if the word can even be applied to them ) and what we consider to be factual seeing.

So the issue becomes much more complexe than simply adding a few cones and guessing what the result is.

Genetically engineering my children

[corvi42]

"within a couple of decades, gene therapy will make tetrachromacy just another option that wealthy parents could check off on the list when they are designing their daughters"

Forget tetrachromacy, I want to have daughters with 6 arms like a shiva... that would be cool =)

Re:Pigeons & Pentachromats

[corvi42]

I'm sorry, but now you're mixing your colour wheels. Mixin blue and yellow only gives you green in a subtractive colour system like with paint. In an additive colour system, like visible light ( which is what our photoreceptors use ) you can't mix anything to make green, because green is a primary - hence we use red green and blue pixels in a computer monitor, not red, yellow and blue.

for every question answered, ten more are asked

[RainMan496]

Trichromatic theory is just that, a theory. It states that colors are viewed as a combination of other pure colors. Soon after it was proposed in the nineteenth century, Ewald Hering noted some unexplained phenomenon. For example, yellow is seen as a mixing of red and green light, yet some who cannot perceive red or green light can still see yellow. Also, why does yellow appear to be a pure color, rather than a mixing of red and green, as purple does of blue and red? He then proposed the idea of opponent processing, based on the occurence of afterimages. For instance, if a red squared is stared at for long enough, and then a white sheet of paper is viewed, a red square will be seen; red is the opponent color of green. This was confirmed through research more than a century later. Some neurons in the thalamus are turned "on" by red and "off" by green. If one color is detected by the retina at a certain point, the opposing color cannot be simultaneously detected at the same point, which is why there is no such thing as a reddish green or a greenish red. All this considered, it is probable that both trichromatic and opposite processing theory are used in the perception of visual images. If these tetrachromats perceive a color between red and green, that totally blows opposite process theory, since it would be like a state between true and false. So if opposite processing theory is not true, then, how does yellow fit into all this? Further research will most likely concentrate on such questions.

you are mistaken

[RainMan496]

Actually, black is not so much a color as it is the absense of all color. There are two physical characteristics of light that determine how we perceive it: wavelength, which determines its hue, and amplitude, which determines its brightness. As rods, which detect black, white, and shades of gray, are not color receptors, black is not technically a part of this group of colors, as are red, green, and blue, or yellow, cyan, and magenta.

you are mistaken

[RainMan496]

Tetrachromats would not see color in a fourth dimension; they see color as being the product of four other colors, rather than three. The difference is great. Color itself in general has three dimensions. It is merely the way that our eyes perceive light. Hue describes the frequency; saturation describes the amplitude; and brightness describes the intensity. There would not be some sort of fourth aspect of light waves to be interpretted. Therefore, tetrachromatic vision does not add a fourth dimension to the perception of color, it merely adds another possible color of perception.

Re:Clothes matching

[Throw Away Account]

In fact, I'll bet men tend to be "slightly" color-blind more often than women. If a man has a 99-01 red/green "red" gene and a 10-90 red/green "green" gene on his sole X will have less acute color vision than a woman with a 99-01/10-90 pair on her first X and a 98-02/03-97 pair on the other.

Re:Pigeons & Pentachromats

[SlippyToad]

Most importantly, how do the First Posters really know that actual conversation exists on SlashDot? Since they're incapable of reading beyond the first five or six comments on a story, they probably have no concept that other conversation takes place, and is actually relevant to the story in question.

Bleen is a Grue Herring

[NetWurkGuy]

The color "Bleen" is not a color between blue and green, (that would be blue-green). Bleen was invented as a partner to "Grue" as part of a logical conundrum. As I recall, (this may not be exact), an object is bleen if it is blue until some arbitrary future date, say Jan 1 2001, and green thereafter. An object is Grue if it is green until that date and blue thereafter.

Re:Anonymous Corrective Poetry

[Trevlig]

Roses are red,
violets are blue,
trichromats can see
that violets aint blue.


THEY ARE VIOLET!!!

Distinguish combinations of frequencies

[Erik from Breda]

I have not yet seen a clear explanation of how a new color in your retina improves color vision. I am no expert in this field, but I have the following hypothesis. Perhaps somebody can verify if this is true.

Trichromats interpret all colors as a point in three-dimensional color space (RGB, which can be translated into Hue, Saturation, Brightness). Tetrachromats interpret all colors as a point in a four-dimensional space (RGG'B, which can be translated into H + S + B + ??).

Most light sources are not of a single frequency, but a combination of frequencies. That is why you can combine two "colors" to make another. I imagine that if you have a fourth dimension, you could distinguish two combinations of frequencies that are indistinguishable for trichromats.

Trichromats are used to Hue/Saturation/Brightness, but a tetrachromat should have some other dimension, but what is it? If we call this "X", then there are (infinite) combinations of frequencies that produce the same HSB (or RGB) sensation, but a different HSBX sensation.

So tetrachromats cannot see colors in a wider spectrum (i.e. they do not have a wider range for the hue), but they can distinguish different light sources with the same hue, saturation and brightness.

*Erik.

TV still works?

[Erik from Breda]

Does this means that tetrachromats will think that colors on TV do not match the real colors of things? Since tetrachromats should be able to distinguish different RGB combinations (having a fourth dimension in which the same RGB combinations may differ), a reproduced color (combination of three colors) can be very different from the original (which produced light of different frequencies but the same RGB sensation).

If more people would be tetrachromats, RGB would not suffice for color TV...

*Erik.

Re:Pigeons & Pentachromats

[Abstinent Whore]

could this be a reason why some people really like some colors, and others really hate the same colors (matching), that they appear completely different. If they were to perceive the same color (see red, see red, when they actually: look at blue, look at green) that would be a difference that makes us think someone likes a certain color over another, when it's kinda the same color. I'm not sure about any of this, for I have been awake for almost 3 days straight, but it makes sense to me.

Re:Nit Pick Alert

[edboas]

As laser pointing becomes more accurate, we ought to be able to stimulate directly our individual cones -- one day somone could perceive "superred" by directly stimulating only the red cones in his fovea. I wonder how different it would look than the more common red?

I have wondered the same thing, and wrote an essay about how this might turn out.

Incidentally, here's a PC World article about a device that can "paint" color images directly onto your retina.

Re:Clothes matching

[swagr]

Actually that comment by Mrs. M. makes no sense at all.

Color is a subjective experience. My experience of a specific "blue" next to a specific "green" might be completely different from everyone else's. In fact, it probably is.
And by "match" what does she mean? *Exact* same color? Look at solid color surface in the room you are sitting in and find 2 seperate spots that are illuminated differently. "Same" color?!?!

Better yet, shine a red light in one eye but not the other for a minute then look at the same object one eye at a time. Is that object simultaneously 2 shades of the same color?

Mrs. M. should shut up.

Re:Even cooler.

[Interrobang]

Naah. It happens to me all the time (usually it's seeing music as colours, but not always), and it gets quite prosaic after awhile.

The only real "effect" I ever had from it was when using an old version of visualization for WinAmp (don't remember the name--ARGHH!), and got mildly irritated a few times because they were the "wrong colours." Then I just picked music to go with the colours and it was GROOVY!

Gee, I didn't realize that most people couldn't do that...

Between Red and Green!?!?!?

[SanLouBlues]

Who cares if their extra colo is part of the already visible spectrum? I wanna see ultraviolet!

Re:Between Red and Green!?!?!?

[Foogle]

Most black lights don't give off *only* UV light. If you can see a glow from them, then they're giving off regular light as well. Or, alternatively, a light could be giving off only UV, but normal light could be produced from nearby objects (like your shirt).

Re:Between Red and Green!?!?!?

[fiziko]

This may or may not be normal. If the black light is a cheap one, it will produce visible light as well, which is the trivial case. It's also possible that a molecule in the page can absorb a photon of UV light, and then emit the energy as one visible photon and one infra-red (or lower energy) photon. Again, it is visible light that reaches your eye.

Re:Between Red and Green!?!?!?

[CausticPuppy]

Anybody can read by a blacklight, at least on most paper. Chances are the paper will flouresce slightly, basically turning invisible UV into visible light. Some paper will flouresce more than others-- depends on how it was made, depending on the brand, etc.
What you see coming from a blacklight (violet) is only a fraction of what's actually there because it's mostly in the invisible part of the spectrum.

Now maybe our corneas also filter out some violet light that we would otherwise be able to see, but I don't know anything about that.

Incidentally, in a dark room with a blacklight on, you can see every single spot on the carpet where your cat has ever barfed, pissed, crapped or where somebody spilled something-- no matter how clean the carpet looks in normal light!
It's quite a hideous sight, although pretty useful for determining where you're supposed to pour the cleaning fluid.

Re:Between Red and Green!?!?!?

[Captain Tenille]

Get cataract surgery, and you'll be able to see UV light. Apparently, it's been noticed that people who've had their corneas removed can read by a black light. I'm not sure what the practicle applications of this would be, but I suppose you could read War and Peace at a rave.

-----------------

who cares...

[DiviN]

if you are smarter? we are in charge.
and we happily give up any type of dominance in exchange for good sex. so what is the problem?
be nice to us, ensure a steady supply of sex and we gladly turn over control to females.
isn't us 'getting some' what we are all about?
isn't that why we start wars, work our backsides off and follow trends to be 'in' and to 'get some'?

the male of the species is so easily manipulated. but then, all we'd have to do to get control back is saying that we love you... ;-))).

Re:Even cooler.

[nurikochan]

Where can I download this? Moreover, how would I compile it for my brain?

First, I'll need to make sure that there is a gcc port for human neuro-structure. I'll also need to make sure I have at least libEYE.so.4.3 and libEAR.so.2.7 installed, along with the appropriate header files.

It'd probably be simple to write something like this, if the hardware existed. put some filter in between, cat /dev/ear > gtk-synaesthesia > /dev/eye.

I have to say it!

[dasunt]

Teenage Mutant Tetrachromat Females!

Now just imagine if we had a beowulf cluster of these? We could analyze all the pictures of Natalie Portman (petrified, of course), in their true tetrachromatic glory! I already have a name for it: Project Hotgrits.

Re:are you color blind?

[Captain Tenille]

Just colorblind. My grandfather figured out a way to cheat on the colorblindness test during WWII somehow, though, so maybe I *am* stupid. :-/

-----------------

Re:It's possible for men, too

[Captain Tenille]

Yeah, but the problems you'd have if you were XXY (Kleinfelter's Syndrome) would more than balance out any benefits of being tetrachromatic. shudder

-----------------

Re:are you color blind?

[Captain Tenille]

I've heard about them, but since I've never not been colorblind, I'd probably get really confused, or something. Could be interesting, though.

-----------------

Want to see if you're colorblind?

[Captain Tenille]

Check here . I didn't do very well at all...
P.S. I swear it isn't a traumatizing link.

-----------------

Re:Want to see if you're colorblind?

[ANONYMOUSE HERO]

Looks like they also sell aphotoshop plug-in. it allows you to do the same simulation on your designs, web pages and photos. Oh, and by they way, I work for 'em.

My friend Zane was blind from birth

[perdida]

and can tell you very well that the brain does adapt to cope with limitations. This proves plasticity up to the "accepted" human limit but not necessarily beyond that limit.

This adaptation often includes finer perceptions developed in other sensory areas; Zane is an audiophile, a musician, and a radio journalist, and sets the levels in the recording studio with little assistance from dial and LED-reading friends.

The question is -- and I will put this to Zane, too -- could someone learn to use prosthetic augmentations -- "Bionic Eyes," robotic prostheses that require a higher reaction time than normally found in humans -- if trained at an early age in a way that encourages neurological adaptation?

Sounds like QuadVision...

[teaserX]

...and the colors on that "synaesthesia" page taste like crap...

Birds

[arcmay]

IIRC from my Sensation & Perception courses, birds are tetrachromats. The more vivid perception of colors makes it easier for them to fly through leafy branches and find their nests.

This is really cool that it has been found in humans, although we trichromats aren't missing out too much. Anything outside of nature that would take advantage of this ability would have to be specially manufactured. TV's, CRT's, photographs, color printers, etc. are not designed to produce colors that would be visible to a tetrachromat but not a trichromat. Instead of RGB color schemes you'd need something with 4 primaries.

-

Re:We already knew this

[Saan]

Great, now all you male IT people know for sure that all this time, your wives see how ugly you guys are. Chill out, atleast she still living with you...after all, with her great eyes...she saw something worth living with.

Re:well.........really

[modified soy protein]

And how

Re:Pigeons & Pentachromats

[BEHiker57W]

In fact, we know that we percieve colors the same way because we have matching colors, fashion, graphic design, pretty flowers, and other color preferences and combinational preferences.

The fact the people (women, anyway) can agree on what is beautiful and visually pleasing without a previously agreed standard proves that humans percieve colors in some similar way. -Brian

Size does matter?

[Kibo]

A brilliant red is something like 6600 A. I would assume something like a shift of 100 A off normal, but, I'm not a molecular biologist. If normal Red is 6.6k A, then 6.5k A for the "off-Red", and Green should be something like 5.2k A IIRC so may be a 5.1k or 5.3k A for "off-green". Ultraviolet would be something like 3.8k A for UVA. All of this is without a textbook, so kids don't try this at home.

Terms and terminology for $100 Alex

[Kibo]

I'm 5 by 5 on the whole call a mutant a spade thing. But is noticeable the right word for the job? I mean, obvious, I can get on that bus. But noticeable? Natural selection tends to be subtle, and without a girlfriend to dress me, I might well never propigate my line. Another fashion victim. Maybe in a world of 10 billion people the only ones who can survive the battle of trendy plumage will be tetrachromates and their color blind boyfriends & sons.

I think I smell SciFi Spice Girls movie in the making, at least it will be better than Starship Troopers.

Yo Momma's so tetrachromatic.....

[Kibo]

when she dresses you, even your girl says your clothes match.

she killed herself in 1972

you came up with the Buccs original colors.

Odd twist, perhaps suburban lore.

[Kibo]

I remember in one of my classes, it somehow came up that during preperation for operations in WWII Americans were field testing night fighting equipment that used the UVA spectrum. Most of the observers couldn't see the trial unaided, but some of them were of Germanic descent and could. This played a large role in the decision for the US armed forces to develop more infared and lowlight optics instead. Or so the story went anyway....

Look through my non-tetrachromatic eyes

[packphour]

"People will think things match, but I can see they don't." What you wouldn't give to see the world through her deep blue-gray eyes, if only for five minutes...

The only person I can see caring about looking through her eyes is Martha Stewart, that way she can have one more way to be anal about wearing the proper colors for the proper season *blah*. Granted, seeing life through the eyes of someone else is interesting- but not for the simple fact that you could tell once and for all if the color accompanying yellow in McDonald's arches is Orange or Red.

"...perhaps the most remarkable human mutant ever identified."

Is it just me or have I been spoiled by X-Men? Whatever, I thought the kid at my elementary school with a sixth finger was cooler than this.

"...genetics dictates that tetrachromats would all be female."

Three words. Horney Heterosexual Scientists.

"Because of a well-known biological phenomenon called X inactivation..."

I was just about to ask if this involved X inactivation, although after they mentioned the green photopigments I wasn't sure.

Just as someone with normal three-color vision surfs rings around a dichromat on the Internet, a tetrachromat, looking at a special computer screen based on four primary colors rather than the standard three, could theoretically dump data into her head faster than the rest of us.

Yeah, well she still can't stand 4 feet from the toilet and pee in it.

(p.s. This was posted in black & white out of consideration for the dichromat audience.)

Re:New colors in vision (new vocabulary?)

[servasius_jr]

"If we ever moved that way, though, would we have to come up with new color words -- words that most of the population couldn't understand?"

Humanity is pretty good at getting by without good linguistic handles for sensory experiences. At the very least, our descriptions tend to be circular, that is, use terminology borrowed from other senses.

I don't think I'm stating this very clearly, so here's an example: the sound of a nice old jazz guitar could be described as warm, ruddy, full, mellow, dark, smoldering, et cetera. Almost any description you come up with refers or likens to another sense. And we seem to get by alright; so no, I don't think our terminology would need to evolve much, even if an entirely new sense was discovered. And by way of corrolary, your average non-mutant would have a fairly good idea of what you were talking about, just because your vocabulary would tend to draw on senses he's familiar with.

Just wondering

[Jedi Alec]

Will we be needing special 64-bit colour graphics for these ladies?

Re:Just wondering

[MouseR]

FYI

Mac OS X uses this extra 8-bits as an Alpha channel for transparency, just like any decent graphics program and video editing tool.


Karma karma karma karma karmeleon: it comes and goes, it comes and goes.

Re:Just wondering

[Trinition]

Yes, perhaps so. Since the tetrachromats can see an additional color between red and green (i.e. yellow?), they can distinguish finer variations of colors in the spectrum. The higher the bit-depth, the finer the differences between colors. What looks like a smooth 32-bit gradient to you might look pathcy to a tetrachromat.

Re:Just wondering

[DickBreath]

I don't think you see the value of having an alpha channel, or transparency channel.

As you point out, it does no good in the framebuffer.

But just think of all the many, many places ahead of the framebuffer where graphics are manipulated? If non-Mac software would universally support alpha channels in graphics formats then think of now naturally graphics would appear to work to end users?

You paste two pictures into your word processor. The two pictures partly overlap. The degree of transparency of each picture (indeed each pixel) is determined by data within the picture itself. Both pictures might be partially transparent so that you could still see the text underneath the two pictures. Bring one of the graphics into the GIMP, crank the alpha channel to fully opaque, now copy&paste the pic back to the word processor, and it obscures everything behind it.

By the time it gets to the framebuffer all you care about is RGB, no alpha.

Another cool thing about this is that you no longer tend to think of pictures as "rectangular". Pictures are arbitrary shaped. Of course, they're rectangular, but just some of the pixels are fully transparent.

Re:We already knew this

[Jedi Alec]

Seems you're handling this kind of situation completely wrong...

HER: Honey, can you find my red shirt for me?
Him, no, I'm busy.

Re:all of my girlfriends?

[Jedi Alec]

Must be a convert geek, or a woman...

Re:New colors in vision

[tallrook]

They've sort of tried this already. In WWII, the U.S Navy experimented with sailors on a diet high in an altered form of beta-carotine. This beta-carotine was more sensitive to infra-red light than natural beta-carotine. The Navy hoped to create people who could see some of the infra-red spectrum-- these sailors would be able to receive infra-red messages sent between ships. They were just starting to get some positive results, when mechanical infra-red sensers were invented. The program was then dropped.

Re:Another blow to the male ego

[NateKilroy]

Can you imagine how those genetically-engineered children will feel? "Mom and dad love me for my genes, not for myself." "If I hadn't been what they wanted genetically, they wouldn't have had me--or would have aborted me." I can see a lot of kids hating their parents over this.

What happens when a tetrachromat gets stoned?

[Anonymous Coward]

Woah! The colors the colors! Just think how much more satisfying the hallucinations would be!

Old news...

[Anonymous Coward]

Geordi from Star Trek TNG could do this ages ago.

Re:We already knew this

[sjames]

So none of the guys' clothes will match in the eyes of women--great. If we don't get female assistance, every woman around will know what losers we are. We'll have to hire women to help us shop, so we can pretend we had girlfriends sometime in the recent past.

Just hack the color scanner used to match paint to do RGBY and attach to PC. Then scan your clothes and discreetly lable them with their RGBY values. OTOH, men will drive women crazy by having no problem with cheap RGB monitors vs the expensive RGBY model.

Re:Photoreceptors... still don't get it...

[sjames]

But, they seem to cover a whole span...there are no blanks where a "color" would hide... When you look at a rainbow, or the light through a prism, there aren't any blank spots.

Look at the slide shows. They show one slide with the spectrum as seen by a dichromat. There are no gaps in it, just yellow at one end and blue at the other (smoothly blending in-between).

A tetrachromat would see the extra primary color between yellow and red or between yellow and green. The other colors would be better defined. So what most of us see as an indistinct shade of greenish yellow, the tetrachromat would see as a distinct shade of [other]

Re:Has Darwinian genetics already ruled against th

[sjames]

It seems likely to me that tetrachromats would have poorer low-light vision than trichromats, or at least would require more light to see in color as opposed to black-and-white. Anybody understand the physiology well enough to clarify?

They probably have a lower threshold for seeing color (greater liklihood that the dim light is near the peak sensitivity of one group of cones). On the other hand, they probably have poorer resolution that trichromats since they either have more cones (and less room for rods), or the same number of cones, but less of each color.

the "scream" test

[hawk]

> So none of the guys' clothes will match in the eyes of women--great.

And this would be different than the current situation *how*?

I've resorted to the "scream test" to get dressed. I come downstairs, and if my wife doesn't scream in horror, I'm ok for the day.

I've given up. We can't agree on which pants are grey and green, and which are blue and black. And she still won't admit that the plaid shirt matched the tasteful and subdued plaid suit . . .

The day I really worried was the time I came out of the shower and found clothes laid out on hte bed. I had to check with a female friend to make sure I hadn't been committing even worse crimes against fashion than usual . . .

hawk

Re:Argh! Read article first, then comment!

[sql*kitten]

If the Males can't see the difference, though, how does this improve desireability (unless it becomes one of those unconsciously perceived bits...)?

Let me give you an example. There are lots of ads on the TV for cosmetic products to be used on eyelashes. Thick, curled lashes are said to be very important. Now, I've never looked at a girl and thought <austin powers>"nice eyelashes, baby, yeah"</austin powers>. But if females are willing to spend $ on products to improve their eyelashes, then it stands to reason that they must have an effect on males that (at least some) males are unable to perceive consciously.

Re:Pigeons & Pentachromats

[jafac]

or, find a willing test subject, who would volunteer to have artificial cone cells sensitive to say 800nm light, implanted in his retina, and connected to nerve fibers newly grown in his optic nerve, then figure out how to train his brain to perceive the signals.

Seems safer to me, than messing with my chromosomes. (presuming that the surgical and biotechnical techniques necessary for such a procedure means that techniques for undoing or repairing damage would also necessarily exist).

Re:The story reports only of the possibility

[AxelBoldt]

Maybe these greenish Slashdot separator bars should contain a tetrachromat-visible message in order to help Dr. Jordan in the search... Not possible to specify a tetrachromat-only visible message in HTML, GIF, PNG etc nor to display such a message on a common color monitor since all of these are based on the RGB system for trichromats.

--

Re:We already knew this

[Mars Saxman]

Goths don't have this problem.

-Mars

UV light considered harmful?

[Pseudonymus Bosch]

Is staying in an environment with ultraviolet light harmful? Like discos and trendy bars?

I know that UV radiation form the Sun and tanning machines is dangerous for the eyes and increases the risk of skin cancer. Are the doses or the range of the decorative UV lamps dangerous?
__

Interesting applications of near-infrared vision

[Pseudonymus Bosch]

Somebody who could see in the near infrared would have capabilities similar to that of the Sony Nightvision cameras that were sold in Japan. If you set the night vision option on at daylight, the camera would be sensible to the infrared and the visible spectrum. One of the amusing results is that you could see through some clothes that happen to be quite transparent on the infrared.

When Sony found this, they rearranged the camera so that infrared detection is not available under normal light.

Or am I wrong?

I can't tell what are the Darwinian consequences of being able to see through the clothes of your potential mates.
__

Re:Interesting applications of near-infrared visio

[Pseudonymus Bosch]

There is a website about "X-Ray" cameras.
__

propogating into the general population - doubtful

[Tumbleweed]

Unfortunately, it almost certainly won't spred into the general population unless it's done on purpose. Tetrachromat vision doesn't give any measurable survival advantage in the modern world, therefore it won't be in a majority of the 'surviving' population.

But, I think we all know that strict Darwinian evolution isn't in force as much in the modern world, anyway. If it's part nature and part nurture, someone having a personality that allows them to succeed in the modern industrial world would only be partly genetic, and thus only partly subject to Darwinian principles of evolution.

But then again - who knows what this _could_ lead to? I'm all for deliberate monkeying with our genetic code - once we understand it. (all hail the Human Genome Project!) There are any number of things we could do to improve our species once we have the knowledge to do so. I even came up with a list last week as I was pondering just such a subject:

• hibernation ability
  
• ability to stealth one's heart signal
  
• rapid healing
  
• photographic memory
  
• distributed brain & heart
  
• improved skeletal system
  
• stronger muscles
  
• faster thought
  
• more networked neurons
  
• retractable male genetalia
  
• second set of eyelids
  
• sharpened eyesight
  
• enhanced visual spectrum detection (Tetrachromat vision)
  
• selectively enhanced hearing
  
• retractable claws
  
• selectively enhanced smell
  
• selective control over body colouring & hair growth (change eye colour, skin colour, hair colour, etc.) Colour should be fast enough for camouflage purposes.
  
• hardened inner ear components
  
• increased vocal range & control
  
• enhanced reflexes & finer motor control
  
• improved, adaptive autoimmune system
  
• improved method of storing oxygen - should be able to hold breath for much longer (see also hibernation ability mentioned above)
  
• gills for breathing underwater or in toxic environments?
  
• toxin-resistance (naval, epidermal, ingested, etc.)
  
• resistance to low & high atmospheric pressure
  
• resistance to temperature extremes
  
• conscious control over adrenaline & glucose levels
  
• conscious control over tastebud sensitivity
  
• high tolerance for pain (or conscious control over shutting off physical sensations in certain areas)
  
• more efficient oxygen transport mechanism to allow slower heart rate
  

And, if we ever figure these things out:

• telepathy
  
• telekinesis
  
• teleportation
  
• clairvoyange
  
• precognition
  
• pyrokinesis
  
• healing of others
  

Why not? We've circumvented Darwinian evolution to a large extent, though, what with the holes in the ozone layer and pollution and all, we might well wind up with a lot more mutants, at least this way it would be controlled.

Even cooler.

[leoc]

I once met a girl who had a condition known as "synaesthesia". It's the kind of condition geeks dream about and design computers to simulate (ie: the visualization plugins on xmms and winamp...)

Re:Even cooler.

[Saige]

Between synaesthesia and this, I really get the feeling that I'm just not experiencing the world as well as I could. Seeing letters as being different colors may not be the most exciting thing, but there seem to be so many others, "seeing" sounds, "hearing" textures, and the like, that seem like they'd enrich the world.

I honestly really feel left out - and get awfully jealous when reading about things like this.
---

Re:We already knew this

[GeorgeH]

You forgot this link.
--

Wonder if Nitrozac could use this...

[alumshubby]

Maybe the TTBs will turn out to be tetrachromats in addition to their other considerable gifts.

Television

[Ed Avis]

The problem with being able to distinguish more frequency ranges than just R, G, B is that normal colour televisions are no longer adequate. Things wouldn't look quite the same on screen as in real life.

(Well, they don't anyway, but it would be worse)

Become a bee, see UV rays as they melt your skin

[Pac]

Bees actually have UV photoreceptors in their eyes. That answers for a part of their ability to guide themselves by the sun. If I remember well, a bee eye has receptor for red, blue and ultra-violet.

Re:Websafe colors?

[PD]

Text. Good old black and white text.

Re:propogating into the general population - doubt

[HeghmoH]

We've circumvented Darwinian evolution to a large extent, though, what with the holes in the ozone layer and pollution and all, we might well wind up with a lot more mutants, at least this way it would be controlled.

Everybody seems to have this perception of evolution as a force that can be gotten around. Evolution is really more of a principle, that because children tend to have traits similar to those of their parents, traits that enable more children, or children who have more children, or anything like that, will tend to become more common.

We haven't gotten rid of human evolution. We've simply changed the traits that get passed on or not. Evolution makes no claim about traits being "good" or "bad", there are simply those that become common and those that don't.

Re:We already knew this

[Xerithane]

So it would be precisely how it is now then? :)
I learned that if I want good clothes you ask a friend (make sure it is a friend) of the female gender to go shopping with you. Most females love to shop, especially if for someone else (I do not understand this phenomenon). The reason it has to be a friend, is if you bring your girlfriend they will buy clothes that they like you in, which would more than likely not be what you like (Another strange phenomenon). I did this and it worked, I met the girl who is going to be my wife next month :)

Re:We already knew this

[mutende]

gene therapy will make tetrachromacy just another option

So none of the guys' clothes will match in the eyes of women

And should the genetically engineered tetra-chromatic woman find herself a husband, all of their sons will be fscking colourblind. How's that for an option?

// Klaus
--

Re:New colors in vision

[Silver A]

Squant

Re:Pigeons & Pentachromats

[grappler]

boggles the mind.

At this point though, you're walking a fine line between science and philosophy. By the same token, how do I know that everyone else is not a zombie? In other words, I can (or think I can) excercise free will and consciousness and explore my thoughts. But perhaps all these people around me are automations that are physically identical to me but don't have that extra "stuff" that makes you a conscious being.

Hurts just thinking about it :-)


-------

Darwin's rulings should be ignored

[Sloppy]

It's possible that it would confuse, add little, and otherwise mess up our ability to see the world.

Or require additional energy or brains.

The thing is, Darwin is finished with us. Or rather, we're finished with him. The relationship between genetic makeup and genetic success has been severely weakened by technology. Humankind's economic power is vastly greater than what it was only ten thousand years ago. Someone who has additional sensory hardware and needs to eat 2% more food might have been at a disadvantage when homo sapiens was first getting off the ground, and his genes would have been selected against. Nowdays, such considerations are irrelevant, so what used to be a bad tradeoff is now a good one.

Just because Darwin selected against something in the past, doesn't mean it's a bad idea. I expect a lot of human hacking to occur in the next thousand years.

---

Re:propogating into the general population - doubt

[Sloppy]

We haven't gotten rid of human evolution. We've simply changed the traits that get passed on or not.

I'm not so sure about that. With the exception of very nasty genetic diseases, I think we have nearly severed the link between the manifestation of traits, and the spread of those traits. Nature does not have technology, political wars, welfare states, etc. A human's fate is more tied to his memetic buildup and environment/chance than his genetic buildup these days. For example, just about anyone who starves to death in the modern world, suffers not from a lack of ability to hunt and gather fod due to genetic weakness. They suffer from living under a bad political system, or from having a religeon that forbids birth control, or something like that.

Hmmm... are you suggesting that the deciding genes that may lead to a new level of natural selection, would be genes that have extremely abstract manifestations, such as a "gene for overthrowing tyranny?" Hmm...

---

What happened to the old color model?

[seebs]

When I learned about color, people saw on two color axes; there's red/green and blue/yellow. This is why some people are "red/green" colorblind; they don't distinguish properly between red and green.

That's *two* axes. RGB is not the way *vision* works, it's the way *DISPLAYS* work; it's additive light. Just like RGY is not the way *vision* works, it's the way *pigments* work.

I can't even begin to find a frame of reference for evaluating this claim, because it contradicts the rest of what we have about color models. We've known for a long time that RGB didn't model, correctly, the whole range of human color vision anyway.

Re:Hey Cool!

[Dr. Zymotic]

You can get the same effect with a B&W QuickCam by removing the infrared filter. Just hook it up to a laptop with an HMD and you're good to go. Instructions for modifying the QuickCam are here:

http://wearables.blu.org/quickcamir.html

The resoltion isn't that great, but the price can't be beat.

Re:Argh! Read article first, then comment!

[weston]

So, Tetrachromatics have an increased chance of catching diseases in their children (improving offspring's chance of survival),

Maybe.

can match outfits better (improving attractiveness and desirability),

If the Males can't see the difference, though,
how does this improve desireability (unless it
becomes one of those unconsciously perceived
bits...)?

Goodbye alpha channel at 32bpp

[Straker Skunk]

64-bit pixels would make sense for four-chromed, alpha-channeled graphics. Anything less than eight bits per channel makes shade variations coarse enough to be visibly noticed, so here's what I would venture:

struct {
int red : 12;
int NEW_COLOR : 12;
int green : 12;
int blue : 12;
int alpha : 16;
} pixel;

Which would probably not work well with today's generation of (32-bit) systems, but should kick ass with the next. And it gives us ordinary trichromats 36-bit RGB color resolution (very cool for GIMP and film work) *and* an ultra-fine alpha channel! Me likes!

[OT] Synaesthesia and the WWW

[Kimble]

If you go back about 5 years or so, the World Wide Web Consortium's logo consisted of three stacked green W's in what looks like the Optima font. They were green because Robert Cailliau, some guy at CERN, is synaesthetic as well -- he sees different colors for different letters, and all his W's are green. He's even got a full-color alphabet there.
--

Re:Pigeons & Pentachromats

[ywwg]

I had a teacher who saw colors "wrong". He wasn't colorblind, but the colors he saw were different from what everyone else saw. He had problems distinguishing odd colors that we would think are very different.

Has Darwinian genetics already ruled against this?

[Benjamin Shniper]

Many animals have the ability to see Ultraviolet and Infrared light. Humans don't. Why is it that species before us like apes, monkeys, and orangatangs never got this super-sight ability?

Maybe it just isn't as useful as we think it is. After the millions of years of evolution we have undergone, we've got pretty groovy bodies and senses as it is. Perhaps Tetrachromatic vision was just an also-ran in the procession of senses that made it to the current draft.

It's possible that it would confuse, add little, and otherwise mess up our ability to see the world. Sure Infrared would kick ass for seeing though solid objects and at night, but there is also a possibility it would be too much of a good thing. Maybe hearing or smell was just more useful than these abilities. The brain cannot efficiently listen on all channels of reality. It has 3 or so channels for hearing and sight, 4 for taste and smell, and maybe 4 channels for touch. (a total of 21) Maybe another channel fed into the brain would overload it in many circumstances and therefore make a person less functional than, say, a trichromat who really used those senses well. Perhaps if we could shut off any new senses more selectively...

-Ben

Re:The story reports only of the possibility

[SEWilco]

Maybe these greenish Slashdot separator bars should contain a tetrachromat-visible message in order to help Dr. Jordan in the search...

Re:Pigeons & Pentachromats

[powerlord]

I don't think the classic Colour wheel can really be used as an indication that we are seeing the same thing, rather it just means that the colors we are percieving react the same way (if we each mix something we perceive and have tagged 'yellow' with something that have perceived and tagged 'blue' we get something that we perceive and have been taught to tag 'green').

Can you see in color?

[SpinyNorman]

Any object is going to absorb/reflect a whole range of different wavelengths of light, not just a single one. To really be able to detect the true color (i.e. light reflective properties) of an object we'd have to have seperate wavelength sensors tuned to each possible wavelength of light! Instead normal people have three color sensors each with different response curves (peaks at red, green and blue) that let us differentiate a broad selection of sets of wavelengths of light...someone with additional sensors with different response curves is going to be able to differentiate (i.e. "see") more sets of wavelengths ("colors") than we do.

Just as someone who's red-green color blind can't see red or green, only "red-green", a trichomat is partially colorblind compared to a tetrachromat. Two objects that appear the same "yellow" color to us may in fact appear as colors "yel" and "low" to the tetrachromat - colors that are as meaningless to us as "red" and "green" are to the red-green colorblind person.

It's possible for men, too

[tbo]

A man with XXY could be a tetrachromat. This is similar to calico cats--normally, only female cats can be calico, but the occasional rare XXY male can also be calico.

Re:Can these abilities be used against Magnito?

[cowboy junkie]

Or at the very least the Mystery Men...

I'm insulted

[QuantumG]

man.. this is the biggest load of shit I have read in a long time. Obviously not a single member of their research team is colour blind. I am colour blind (very much so, I wear pink shirts to work) and I find their claims about using the Internet to be utterly false and insulting. I think their testing conditions must have sucked (if they did any testing) or the sites they visit are a lot different to the ones I visit.

Re:Klinefelter's Syndrome

[nano-second]

No. According to the article:
"Here it gets interesting. Suppose a woman inherits one X chromosome with two slightly different green photopigment genes. And let's say her other X chromosome has the normal complement of red and green photopigment genes. Because of a well-known biological phenomenon called X inactivation -- which causes some cells to rely on one X chromosome and others to rely on the other -- that woman's retinas would have four different types of photopigments: blue, red, green, and the slightly shifted green. (It would also be possible, through a different genetic sequence, to produce blue, green, red, and a shifted red.) X inactivation is only possible in women, so there has never been, and probably never will be, a male tetrachromat."

So you see, it doesn't matter which parent has the tetrachromacy, a "normal XY" male child will not have the opportunity for tetrachromatic vision, because he will only have one X chromosome.
---

And even worse ...

[gotan]

You could make signs only a tetrachromat can read ... Hows that for paranoia and the age old conspiracy theme?

Color is much more than a wavelenght

[Gorimek]

A better question might be "Can living beings perceive an infinite amount of colors?" Color is just a function of wavelength, and there is obviously an infinite number of discreet wavelengths within the visible color spectrum.

This is, or at least touches on, a common misconception. I'll try to explain.

There is vastly more color information in what we see than we percieve. Yes, monochromatic green light has only one frequence, and is percieved as green. But simultaneous blue and yellow light contain two different frequencies, and is percieved as the exact same green color. And it doesn't even contain any green light!

Almost any light we see is made up of a huge number of frequencies, which our eyes and brains, using 3 measuring points, somehow averages out to one single color that it presents to us as what we "see". But there is much more in the light than the small summary we see.

One application of this is cameras that "see" in different frequencies that are used for air surveilance. A camouflage that may look like it melts in perfectly to the human eye, may be made up of completely different frequencies, and be easily detectable this way.

Re:Color is much more than a wavelenght

[cr@ckwhore]

This may be a great description of how a tetrachromat sees color! To us lowly trichromats, our best understanding is that perhaps it provides the ability to distinguish green waves from mixed blue and yellow waves. (I think yellow is technically a "green wave".)

Fascinating stuff!

What about our sense of smell?

[wowbagger]

According to an article in Science News (sorry, the article itself isn't online, but here's the references for the article), about 70% of the genes that code for chemoreceptors in our olfactory bulbs are faulty (in the average person. For some people it's worse). For dogs, the number of genes is roughly the same as humans, but all of theirs work.

The question is, what would happen if you modified a human embryo to correct this? ( patch -d1 <good_genes.diff) Would you get a human with a dog's level of scent-awareness? Would some other sense suffer (less visual acutity/worse hearing/???) Remember that even in humans, the olfactory bulb is wired in pretty fundamentally (down in the reptile part of our brain.) Consider how smells can trigger memories. What then?

Also, most folks here have been talking about having infrared. Sorry, but you aren't going to be able to see thermal IR: your own body heat would jam it. At best, you could see "optical" IR like your remote control puts out. Unless you are trying to break into a security area that uses IR detectors, or you like watching your Palm talk to your Furby (get your minds out of the gutter, you trolls, and into the sewer with the rest of us) this would be of little use.

my reception vs your reception

[Speare]

How do you know that we both perceive colors the same way? Perhaps the way I perceive blue in my mind looks just like the red that you perceive in your mind.

I used to consider this a problem, but really, it is moot. If I can say "red" and you know what I mean, and if you can say "blue" and I know what you mean, then it's all hunky dorey. We all perceive some color approximately n nm wavelength as a given name for a hue, and that is all that matters.

Now, if we took my eyeball or optic nerve and transplated it in you, maybe something would register with different synaptic signals. You'd see a solarized (hue shifted or mangled) signal. You might not even be able to interpret my brightness signals. However, your brain would, if given some time, retrain itself to the new inputs.

Hey Cool!

[Greyfox]

I've been wanting to hack up a wearable partially because I want to be able to see into Infra-red. It's kind of neat to hear about humans with extra senses without the hardware. Though it'd be handy to be able to turn something like that on or off at will.

Maybe by the time I have kids, I'll be able to engineer their gene code to include this ability and others like it...

Re:Squant!

[glacial23]

Actually, here's the link. The plug-in works great, once you get it installed...

We're bought and sold for corporate gold

Re:That's because the moonlight actually is blue.

[Dr. Zowie]

Sorry to say, I'm just not buying this. Ever taken a long-exposure color photograph by moonlight? Colors come out normal. Similarly, ever looked at moon rock? It's about as close to neutral grey as a rock can get.

that's nothing....

[Raymond Luxury Yacht]

... You're just trying to see like a woman. All of Mankind has been trying to think like one for centuries.

If we could think like them, things like "feel good movies" and potpoury (sp?) might one day make sense as well!

Re:We already knew this

[mangu]

So, married and otherwise compromised guys looking for an adventure would keep an extra, non-matching, set of clothes hidden in a drawer at work?

Re:Yes it is the exact term you would use.

[gwalla]

Im sure if you looked closely enough, most of us have some sort of genetic mutation in our DNA, but they just arent significant enough to manifest themselves in any noticeable way.

Actually, we're all just mutant protozoa.

---
Zardoz has spoken!

Klinefelter's Syndrome

[istartedi]

Klinefelter's Syndrome is where a male is XXY instead of XY. Most such men are infertile, but according to NIH some can father children.

So, if a female tetrachromat passes the gene to a Klinefelter child, and that man fathers a son, could the son be a "normal" tetrachromat male?

Of course we are talking about multiplying several very small percentages together, so the odds are very low, but it's still interesting.

I think it's far more likely that someone will hack the genes to create a male tetrachromat. Imagine what it would be like if DaVinci, Van Gogh, or some other great artist had the capability. Then again, imagine what it would be like if they screwed up and caused his testes to produce the Ebola virus instead of sperm.

Another blow to the male eog

[tylerh]

the possibility that, within a couple of decades, gene therapy will make tetrachromacy just another option that wealthy parents could check off on the list when they are designing their daughters.

Wonderful, as if we males don't already get enough grief from females about our lack of fashion sense....

Nit Pick Alert

[fm6]

The article kind of oversimplifies the concept of color vision. It's true that most people have three kinds of color receptors. But there's no particular connection with the RGB color space.

First off, receptors are not color specific. They respond to all visible radiation. They do have three different response peaks, which is why your monitor can fake you out using only three diffent kinds of flourescent dye. But there's nothing magical about "red", "green", and "blue", You can base a color space on any three non-complements. (Printers prefer Cyan, Yellow, and Magenta.) In fact, everybody's response curve set is slightly different, so the RGB frequencies on your monitor probably don't correspond to your actual receptors.

Come to think of it, I'm not even sure the "normal" response peaks correspond to anything like red, green, or blue. But I'm no expert. Is there a neurobiologist in the house?

It's also important to distinguish between ideal color spaces and implementations thereof. Your monitor generates red, green, and blue by flourescing specific dyes. These dyes are chosen for practical reasons, and the colors they generate aren't really "pure". A color space lives in an ideal, platonic place where there primary colors have a pure state that doesn't exist in nature. Anything in the real world is a mixture of multiple wavelengths.

__________________

Re:Nit Pick Alert

[King Babar]

There's a really interesting overview article on color vision in the Feynman Lectures, volume I. It includes typical spectra for R, G, and B dyes. If I recall right, R and G are actually rather similar spectrally, with somewhat broad humps in the long end of the spectrum, while the B dye has a very different spectrum with a sharp peak near the short end of blue.

Most of this post was essentially correct, but I just wanted to amplify this part of the message. Yes, if you look at the spectral sensitivities of red, green and blue cones (or, strictly, their dyes), blue is many nanometers shorter in wavelength than the difference between red and green. But to test your understanding of how color "works" at the retinal level, the key question should be: where does "yellow" come from?

The answer, of course, is from the additive contributions of both red and green cones; indeed, when you look at the sensitivity curves, you can see that the response to "yellow" should be larger than either green or red. And, it is. Visual acuity is actually slighly better for yellow than for any of the primaries (think shooter's glasses). Now, having said that, I should point out that blue is a special weird case, since the blue cones have a much more limited distribution on the retina than do red and/or green cones.

And, having said all of this, the most amazing thing about color vision (in my opinion) is not what happens at the retina, but what happens in the cortex, apparently in area V4. That's where the very hard problem of color constancy (aka "discounting the illuminant") is solved in a manner studied at great length by Edwin Land, who really would be every geek's hero if only he were better known.

Re:Nit Pick Alert

[Dr. Zowie]

Actually, that's not quite right. RGB space works because most people have three main broadband color receptors. And, yes, the primary colors have to be red, green, and blue (more on that later).

Sure, the dyes each represent vectors in the full infinite-dimensional spectral space, and not simply particular wavelengths -- but so long as they're linearly independent (i.e. you can't generate the spectrum of any one dye out of a weighted sum of the other dyes' spectra), they're useful for distinguishing color.

The primary additive colors (R, G, and B) are determined by the spectra of the dyes. You can't pick any set of primary colors you want -- the color wheel was discovered experimentally long before we knew the cellular biology to do direct experiments on the human eye. The primary subtractive colors (C, M, Y) are made by subtracting the corresponding (R, G, or B) from white light -- cyan light has G and B components, but no R.

When you get into detailed color vision, things (as always) get more complex. It turns out that there are no precise primary colors that everyone can agree on, because not everyone uses the same dyes in his cones! There are slight variations across the population, so that the R, G, and B primary colors correspond to different pieces of spectrum depending on who's looking.

Because of the overlap of (for example) the R and G spectra, it's not normal possible to generate a pure R signal in the human retina with any single wavelength of visible light. But we're wired to do the linear decomposition ourselves: in effect, the differential gain is really high between the R and G "raw" channels coming out of our retinas. Cool, eh? As laser pointing becomes more accurate, we ought to be able to stimulate directly our individual cones -- one day somone could perceive "superred" by directly stimulating only the red cones in his fovea. I wonder how different it would look than the more common red?

There's a really interesting overview article on color vision in the Feynman Lectures, volume I. It includes typical spectra for R, G, and B dyes. If I recall right, R and G are actually rather similar spectrally, with somewhat broad humps in the long end of the spectrum, while the B dye has a very different spectrum with a sharp peak near the short end of blue.

Re:You too can have extra-trichromat vision

[-Harlequin-]

Cool - we could look like those guys in City of Lost Children :-)
I would love to play with those things. If you ever do go into production, you've made one sale here :-)

Wow - and with a bit of work and study, you could probably learn to use these to colour-coordinate in tetrachromatic space, then you could be the only guy in the world who looks stylish to tetrachromats, who are all female...
(Hey - it's just a thought! :-)

Re:Woman can pee standing up

[talesout]

You shouldn't need to use a search engine. Just go to your favorite porn site (with sick fetishes) and you can see all the photographic proof you need that women can pee standing up. Of course, in these pictures they aren't usually aiming at a "proper" urine receptacle, but what the hell, to each his/her own.

Trying to visualize

[JCCyC]

Let's say you have two lamps which emit pure-wavelength red and green. Point those to a white wall and you'll see yellow. A third lamp emits pure-wavelength yellow. Point that to the wall and you'll see the same yellow.

Now our X-Woman would look at these two experiments and say, "How can you say it's the same color? It's not!"

Did I get it right?

Great...

[glowingspleen]

Now not only does my sweater not match, but it doesn't match my slightly translucent glowing aura.

Change that shirt

[SubtleNuance]

Great, now every man -not just the colourblind- will have to listen to his wife nag that he dosnt know how to dress himself.

Color as subjective experience

[sulli]

True enough. But I do think Mrs. M. has a point. There may be hues of color that are undetectable by a "normal" (trichromatic) human eye but that are quite jarring to a tetrachromatic eye - much in the same way that someone who detects very high or very low pitch may think differently about a piece of music, or a type of noise, than you or I might.

Of course illumination has an impact - but if there's a hue that is fairly strong, the strength of said hue will outweigh it, like a deep bass or high whistle can be heard over other sounds.

Re:Color as subjective experience

[Mr. Protocol]

Yes. This is exactly right. Consider it this way:

The color receptors in the eye are not monochromatic, that is, they don't react to just one frequency of light. Instead, they react in a curve, with a peak at the frequency of greatest sensitivity of that particular color receptor. What goes into the visual channel, then, is the output from each kind of receptor. Their curves overlap, so all three of them would react (at very different levels) to a monochromatic light.

Now, let's say we have four monochromatic light sources, one at the peak frequency of each of the receptors in "Mrs. M's" eyes. To further simplify matters, let's pretend that a "normal" eye's color receptors have peaks at the same frequencies of three of Mrs. M's four receptor types. Call them R, G, B and Q, where Q is the color receptor that the normal eye doesn't have.

Shine equal intensities of R, G, and B into the normal person's eye. The three color receptors will respond with a particular color, probably white. Now, add in color Q, and at the same time, decrease R, G and B so that the response from each of the normal receptors for R, G, and B remains the same. The normal person will see no difference. They can't, we've made sure of that: their color receptors are putting out just the levels they did before.

Now, shine these two different combinations into Mrs. M's eyes. She'll see two VERY different colors. Her R, G and B receptors will be putting out the same levels in both cases, but her Q receptor will jump way up on the second combination. Result: the "white" light suddenly looks Q-colored. What color that actually corresponds to in normal vision depends on where the peak of the Q receptors lies in the spectrum. Could be aqua, cyan, anything.

Re:Yes it is the exact term you would use.

[Mtgman]

If the 4 color vision is a good mutation, it will hopefully propogate into the general population eventually (well, half of it anyway :)

Is that supposed to be a pick-up line? I bet she could see right through it.

Steven

Re:Pigeons & Pentachromats

[BluedemonX]

If they're so bloody good at visual perception...

why do they keep sh^tting on my car thinking it's a body of water?

Yet another egghead theory shot down by common sense.

Still no hope for drivers....

[SomeoneGotMyNick]

It's a shame that the other 'color' that trichromats can sense isn't an ultraviolet one instead of another shade of green as the story indicates.

Enhanced night vision with ultraviolet perception would be very beneficial when it's dark and would greatly counteract a woman's inability to drive during the day...

what makes my brain hurt...

[gtx]

it makes my brain hurt just trying to imagine what having 4 color vision would be like... kinda like trying to imagine 4 dimensional space... ooh... headache....

Re:Most people are tetrachromats (of a sort)

[tswinzig]

At night, when we're seeing mainly with our rods

That's strange. At night I think mainly with my rod. Or at least that's what my girlfriend says.



"Extraordinary claims require extraordinary evidence."

Re:Pigeons & Pentachromats

[plastik55]

My private theory has always been that colours are analogous to musical tones. Under this theory, while there may be an infinite number of frequencies and hence an infinite number of distinct "colours", they actually sort themselves out into a limited number of hues analogous to the tones of the musical scale.

Confused--what do you mean by "hue" as opposed to "color?" Do you mean that we perceptually segregate colors into hues?

In the brain, the three types of color receptors (call them R, G, and B) feed input to circuits in the lateral genticulate nucleus (LGN). In the LGN there are circuits which recombine the colors to form three new axes: and "intensity" axis (R+G+B), a "red-green" axis (R-G) and a "yellow-blue" axis (R+G-B) This is because the "red" and "green" photoreceptors actually overlap over most of their range, so to get useful information out of them, you need to take the difference. This also has the peculiar result that most beople can't imagine colors that are in between green and red, or betwen blue and yellow.

(actually, what I should say is that it is known that the monkey LGN works this way, and we have no reason to believe that the human LGN works differently.)

Since the top (violet) end of our visual range is less than twice the frequency (more than half the wavelength) of the bottom (red) end, we perceive less than one full visual "octave".

The reason that very high frequency light looks purplish (hence "ultraviolet" instead of "ultrablue") is because it starts to excite the red photoreceptors in addition to the blue ones. If it only excited the blue receptors, it would look blue. It happens that some very high frequency where the blue receptors are barely excited (remember the response of a photoreceptor, plotted against frequency, looks like a bell curve--receptors respond to a range of frequencies.) is twice a frequency that is near the bottom of the red range. There is a resonance phenomenon (ask a quantum chemist, I'm just a neurobiology student ;) that means that the red photopigment can be excited weakly by radiation at twice the frequency of its fundamental. So near-ultraviolet light is picked up by both red and blue receptors.

Lie Detection By Color

[namespan]

So when I was a kid, somewhere I heard the idea -- maybe from my mother -- that you could tell whether or not someone could was lying by looking at their face coloring. A flush of a "yellowish" color was said to enter the forehead of a liar.
Hmmm.

I'd always thought it was a psychological ploy: if someone claimed they could tell when you were lying, then you may as well give up and tell the truth.

But if there are tetrachromats, or even other kinds of better vision, maybe they CAN see things like this....

Re:Anonymous Corrective Poetry

[Private Essayist]

Thank you, that's a much better version than mine.
________________

Re:We already knew this

[Anonymous Coward]

This could be even worse in a couple decades. From the article: And that confirmation would raise the possibility that, within a couple of decades, gene therapy will make tetrachromacy just another option that wealthy parents could check off on the list when they are designing their daughters. It won't be possible with male children -- not for quite some time, anyway.

So none of the guys' clothes will match in the eyes of women--great. If we don't get female assistance, every woman around will know what losers we are. We'll have to hire women to help us shop, so we can pretend we had girlfriends sometime in the recent past.

Definitive explanation of color vision

[raph]

A lot of comments here reflect a somewhat, uh, uninformed view of color vision. I was going to write up a little summary, but then decided to try my Google skills out.

I came up with this definitive article on Color Vision by Peter Gouras. It's very deep, with a special focus on the neurology of color vision.

Another potentially interesting link is the Color Vision Q&A from Rochester Institute of Technology.

What's especially fascinating to me about color vision is that it still isn't fully understood. The low level parts, such as rods and cones, and even some of the "early vision" parts of the brain, have been studied for a while now. However, there are lots of higher level brain activities that are still quite mysterious. As such, making color photographs "match" across computer screen, print, video, etc., is still a subjective art, claims of rigor in "color management solutions" notwithstanding.

You too can have extra-trichromat vision

[raph]

The trick is to use a pair of my patented spectral shifting eyeglasses. The extra colors are visible as discrepancies between the two eyes, a somewhat glittery effect.

I have a prototype pair here. I haven't done an experiment along the lines of Dr. Jordan's, but my intuition is that you'd be able to pass the tetrachromat test.

In theory, this technique can give you up to hexachromic vision. In practice, the color shifts in the yellow area are by far the most pronounced.

The prototypes cost me about $1000. The optical coating technology is pretty straightforward, and it should be possible to manufacture these in quantity for $20-$30. Anyone interested in going into production?

Re:propogating into the general population - doubt

[Tumbleweed]

> Evolution makes no claim about traits being "good" or "bad", there are simply those that become common and those that don't.

I'm not sure how you think that some traits will get passed on, though. It's not through magic. If the traits in one type of mutant wind up being passed on, great. It's only going to GET passed on if that creature reproduces, which it won't do, or won't do ANY MORE THAN THE NON-MUTATED ONES, unless there's that mutant is in some way 'superior' as far as getting their genes propogated. Otherwise, those genes would wind up staying in approximately the same projected percentage as they are currently. Unless the progeny of the mutant becomes statistically more-numerous than the non-mutants, it won't become commonplace.

Slightly-improved colour detection in this day and age will do little to nothing to make those people able to reproduce more than a non-mutant. _Maybe_ the ability to detect one's progeny being ill _slightly_ faster than another might help, but with modern medicine - I find it highly unlikely.

Re:Pigeons & Pentachromats

[ElrondHubbard]

My private theory has always been that colours are analogous to musical tones. Under this theory, while there may be an infinite number of frequencies and hence an infinite number of distinct "colours", they actually sort themselves out into a limited number of hues analogous to the tones of the musical scale. The reason we are unaware of this phenomenon is that the human visual range extends approximately from 700nm to 400nm. Since the top (violet) end of our visual range is less than twice the frequency (more than half the wavelength) of the bottom (red) end, we perceive less than one full visual "octave".

Of course, the only way to test this theory, as far as I can tell, would be to engineer some lucky (or unlucky) child with the genes for extended-range pigments, let them grow up, and then ask them if 400nm light looks somehow the same or different than 800nm light.

Photoreceptors

[Lish]

This site gives some insight as to how photoreceptors work, and may help explain what you're asking. The focus of the site is color-blindness, but it's the same sort of idea; take photoreceptors away vs add a new kind. Try the "Basics" section.

Neitz Color Vision Lab

Clothes matching

[sulli]

Mrs. M. said:

"People will think things match, but I can see they don't."

Does this mean that all of my girlfriends have been tetrachromatic? I often hear this about my clothing...

Argh! Read article first, then comment!

[dasunt]

Tumbleweed writes: Unfortunately, it almost certainly won't spred into the general population unless it's done on purpose. Tetrachromat vision doesn't give any measurable survival advantage in the modern world, therefore it won't be in a majority of the 'surviving' population.

If you read the article, you could have avoided shooting yourself in the foot.

From the article: Would there be any practical advantages to tetrachromacy? Dr. Jordan notes that a mother could more easily spot when her children were pale or flushed, and therefore ill. Mrs. M reports that she has always been able to match even subtle colors from memory -- buying a bag, for example, to match shoes she hasn't laid eyes on for months. And computers, color monitors, and the Internet raise a whole raft of possibilities. Just as someone with normal three-color vision surfs rings around a dichromat on the Internet, a tetrachromat, looking at a special computer screen based on four primary colors rather than the standard three, could theoretically dump data into her head faster than the rest of us.

So, Tetrachromatics have an increased chance of catching diseases in their children (improving offspring's chance of survival), can match outfits better (improving attractiveness and desirability), and might be able to intake more data.

Not sure how this sounded to you, but I'd say that the genes for Tetrachromatics are beneficial (at least to the female half of our population).

Re:Yes it is the exact term you would use.

[Jedi Alec]

there aren't any superheros flying around in the real world

That's what you think. Guess you're a trichomat, right?

Re:Pigeons & Pentachromats

[BeBoxer]

By the same token, how do you know that we both perceive colors the same way? Perhaps the way I perceive blue in my mind looks just like the red that you perceive in your mind. We all kind of assume that we see the colors the same way. But, it could easily be the case that they we all see them differently.

Sure, things like the color wheel dictate a certain amount of consistency in each individuals perception. But the color wheel could be rotated to a different angle for each person. Or perhaps the world to me looks like an inverted negative to you. The fun part is that there is absolutely no way to tell.

Websafe colors?

[toolie]

Does this mean that the web safe palette drops from 22 to 2? Just black and white now...

New colors in vision

[Valdrax]

If the human brain can adapt to 4-color sight, then I wonder how much longer before someone tries to engineer extra infra-red cones. Infrared-sensitive eyes have long been a part of the cyberpunk genre of fiction, but the idea of growing up with "natural" infrared vision in addition to normal color vision would be wonderful.

If we ever moved that way, though, would we have to come up with new color words -- words that most of the population couldn't understand?

Most people are tetrachromats (of a sort)

[Dr. Zowie]

The rods in your eye have a fourth photosensitive dye beyond the usual (R,G,B) sets -- rhodopsin. They're not ``wired'' the same way as regular (R,G,B) cones are, so they don't contribute as strongly to color vision -- but they do contribute. Why, for example, do stage managers use blue light to signify darkness in the theater? Because rhodopsin responds more to blue light than to red light. At night, when we're seeing mainly with our rods, we see mainly blue things. (as an experiment, take a swatch of blue cloth and a swatch of red cloth (of about equal darkness) out into moonlight. The blue cloth will appear lightly shaded and the red will appear darker, because your rods are more sensitive to the blue light.

There might be colors (shades of blue and violet) that can be distinguished at twilight but not in bright sunlight because of the importance of rods to vision in the reduced light. I keep meaning to go check, but haven't.

Yes it is the exact term you would use.

[Ratteau]

A mutant is the term you would use because the scientific term for what this woman has is a genetic mutation.

It is actually such things as the X-Men that gives the term a misunderstood meaning. A mutation doenst have to be anything as drastic as in the movie "The Fly" for example, and certainly, there arent any superheros flying around in the real world. Im sure if you looked closely enough, most of us have some sort of genetic mutation in our DNA, but they just arent significant enough to manifest themselves in any noticeable way.

If the 4 color vision is a good mutation, it will hopefully propogate into the general population eventually (well, half of it anyway :)

Cones see Colour

[dmatos]

Rods see intensity (ie B&W). A couple more interesting facts: rods react to changes more quickly, and to smaller changes as well. Cones are concentrated around the centre of your eye, whereas there are relatively many more rods in your peripheral vision. This is why it is easier to see movement out of your peripheral vision, and easier to spot something that is a different colour by looking directly at it. Pretty cool if you ask me. Peripheral vision sensitive to movement to spot attacking predators, and central vision sensitive to colour differences to spot hiding prey...

Re:Pigeons & Pentachromats

[arcmay]

Does that mean that there are an infinite amount of colors, because a pentachromat (some animals have five color receptors) would see even more colors.

A better question might be "Can living beings perceive an infinite amount of colors?" Color is just a function of wavelength, and there is obviously an infinite number of discreet wavelengths within the visible color spectrum.

Scientists have come up with some finite number of colors that can be percieved by humans. (I can't remember the exact count off the top of my head - check any perception textbook.) However, a machine with high quality photon sensors can distinguish between a much higher number of wavelengths, even though it doesn't have the perception of color. If we wanted it to describe that color for us as a perceptual experience, it would simply map that wavelength to a human-defined color table.

It is fair to say that there are an infinite number of colors out there, just that we can't see them all.

-

Can these abilities be used against Magnito?

[Mr. Neutron]

Mutant color-sensing abilities? Call Dr. Xavier. Sign her up! ;-)

--
"How many six year olds does it take to design software?"

thats all!

[DeadSea]

Forget an extra receptor, when I was growing up I could have sworn that my mom had a whole extra eye in the back of her head.

The story reports only of the possibility

[intuition]

The slashdot headline is premature in stating that a tetrachromat had actually been found.

"Nevertheless, Dr. Jordan declines to say that she has finally found a tetrachromat, partly because her testing is still a work in progress."

We already knew this

[Trinition]

We've alreay know women see more colors than men for a long time...

HER: Honey, can you find my red shirt for me?
HIM: Yeah, here it is.
HER: No, dear, that's the magenta one. I wanted the red one.
HIM: Is this it?
HER: No, that's burgundy. Forget it. Just give me my cream sweater instead.
HIM: Cream? Is that white?
HER: It's almost white but has a little yellow in it.
HIM: Here it is!
HER: You moron! That's a khaki colored sweater. I wanted the cream one! MEN!

Re:Has Darwinian genetics already ruled against th

[mikeee]

>they just have extra reception

Er, I don't thinks so. They have a different *distribution* of receptors - four kinds (instead of three) with relatively tight color-bands, and one type which responds to the full visible light spectrum. This is why you can see B/W in very low light - still enough to trigger enough of the broad-spectrum receptors, but not enough for the tight-spectrum color recievers. This is why animals with very good night vision usually can't see color - they punt the color entirely for extra broad-spectrum receptors.

The space for those extra receptors in a tetrachromat came from somewhere, presumably other color receptors. I would *guess* that means they need more light to see in color than we do, but see finer color gradients....??

Pigeons & Pentachromats

[jbischof]

Pigeons have tetrachromat vision as well. My question though, is do they see a fourth and different color?, OR are the colors we see spread out a larger spectrum for them?? I know the frequencies are higher (or lower), Im talking about what shade it looks like in their brain, the whole how do you know when I look at grass I dont see red and call it green? According to a theory, this is similar as the difference between the vision of a dichromat (a color-blind) and a normal trichromat, like most of us. It means that a tetrachromat can have a novel pair of colors similar to our yellow-blue and red-green pairs. I would really really like to have the sensory output from her eyes fed into my brain, dont you think they could hook that up? Does that mean that there are an infinite amount of colors, because a pentachromat (some animals have five color receptors) would see even more colors.

Tetrachromat poetry

[Private Essayist]

"The vast majority of us have no idea what tetrachromacy would be like. Anyone who had the supersense wouldn't know she did, let alone be able to describe it. After all, it is an exercise in futility for trichromats to try to explain their visual experience to color-blind people. "

Roses are red,
violets are blue,
trichromats can't see
the other amazing hues
________________