
Mutant Tetrachromat Females Found 434
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."
What happens when a tetrachromat gets stoned? (Score:2)
Old news... (Score:2)
Re:not a new color (Score:2)
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.
Re:We already knew this (Score:2)
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... (Score:2)
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 (Score:2)
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 (Score:2)
> 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! (Score:2)
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 (Score:2)
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 (Score:2)
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Re:We already knew this (Score:2)
-Mars
Re:Just wondering (Score:2)
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.
UV light considered harmful? (Score:2)
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?
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Interesting applications of near-infrared vision (Score:2)
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.
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Re:Interesting applications of near-infrared visio (Score:2)
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propogating into the general population - doubtful (Score:2)
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:
And, if we ever figure these things out:
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. (Score:2)
Re:We already knew this (Score:2)
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Wonder if Nitrozac could use this... (Score:2)
Television (Score:2)
(Well, they don't anyway, but it would be worse)
Become a bee, see UV rays as they melt your skin (Score:2)
Re:Websafe colors? (Score:2)
Re:propogating into the general population - doubt (Score:2)
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 (Score:2)
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 (Score:2)
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Re:New colors in vision (Score:2)
Re:Pigeons & Pentachromats (Score:2)
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
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Darwin's rulings should be ignored (Score:2)
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.
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Re:propogating into the general population - doubt (Score:2)
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...
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What happened to the old color model? (Score:2)
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! (Score:2)
http://wearables.blu.org/quickcamir.html [blu.org]
The resoltion isn't that great, but the price can't be beat.
Re:Argh! Read article first, then comment! (Score:2)
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 (Score:2)
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 (Score:2)
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Re:Pigeons & Pentachromats (Score:2)
Re:"mutant" (Score:2)
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
Has Darwinian genetics already ruled against this? (Score:2)
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:Something that I have thought about for a while (Score:2)
I believe a search here on Slashdot for "cat eye" will let you see through the eye of a cat.
Re:The story reports only of the possibility (Score:2)
Re:Pigeons & Pentachromats (Score:2)
Re:far red vision (Score:2)
Re:"mutant" (Score:2)
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.
Can you see in color? (Score:2)
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 (Score:2)
Re:Between Red and Green!?!?!? (Score:2)
Re:Can these abilities be used against Magnito? (Score:2)
I'm insulted (Score:2)
Re:Even cooler. (Score:2)
I honestly really feel left out - and get awfully jealous when reading about things like this.
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Re:Klinefelter's Syndrome (Score:2)
"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.
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Re:"mutant" (Score:2)
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.
And even worse ... (Score:2)
Color is much more than a wavelenght (Score:2)
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:IR and UV in other creatures (Score:2)
What about our sense of smell? (Score:2)
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 (Score:2)
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! (Score:2)
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! (Score:2)
We're bought and sold for corporate gold
Re:Between Red and Green!?!?!? (Score:2)
Re:"mutant" (Score:2)
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:That's because the moonlight actually is blue. (Score:2)
that's nothing.... (Score:2)
If we could think like them, things like "feel good movies" and potpoury (sp?) might one day make sense as well!
Re:Just wondering (Score:2)
Re:Where are these other colors? (Score:2)
Re:I thought the thirties... (Score:2)
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:Where are these other colors? (Score:2)
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? (Score:2)
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:We already knew this (Score:2)
Re:Yes it is the exact term you would use. (Score:2)
Actually, we're all just mutant protozoa.
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Zardoz has spoken!
Klinefelter's Syndrome (Score:2)
Klinefelter's Syndrome is where a male is XXY instead of XY. Most such men are infertile, but according to NIH [nih.gov] 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.
Re:We already knew this (Score:3)
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 (Score:3)
I came up with this definitive article on Color Vision [utah.edu] 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 [rit.edu] 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 (Score:3)
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 (Score:3)
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 (Score:3)
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.
Re:Nit Pick Alert (Score:3)
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:Color as subjective experience (Score:3)
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:Between Red and Green!?!?!? (Score:3)
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.
Photoreceptors (Score:3)
Neitz Color Vision Lab [mcw.edu]
Re:"mutant" (Score:3)
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
Clothes matching (Score:3)
"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...
Re:Just wondering (Score:3)
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:Where are these other colors? (Score:3)
Argh! Read article first, then comment! (Score:3)
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:Between Red and Green!?!?!? (Score:3)
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Re:Yes it is the exact term you would use. (Score:3)
That's what you think. Guess you're a trichomat, right?
Re:Pigeons & Pentachromats (Score:4)
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? (Score:4)
New colors in vision (Score:4)
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) (Score:4)
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. (Score:4)
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 (Score:4)
Re:Pigeons & Pentachromats (Score:4)
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.
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Can these abilities be used against Magnito? (Score:5)
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"How many six year olds does it take to design software?"
thats all! (Score:5)
The story reports only of the possibility (Score:5)
"Nevertheless, Dr. Jordan declines to say that she has finally found a tetrachromat, partly because her testing is still a work in progress."
Re:Nit Pick Alert (Score:5)
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.
We already knew this (Score:5)
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 (Score:5)
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 (Score:5)
Tetrachromat poetry (Score:5)
Roses are red,
violets are blue,
trichromats can't see
the other amazing hues
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