Isn’t a being a tetrachromat painter like being a supertaster chef? They’re each going to be making things the rest of us cannot fully appreciate. My mother has a very sensitive sense of smell but prefers fairly bland food, I reckon because the subtleties she can detect are enough for her; Indian food OTOH is utterly overwhelming. Won’t touch it.
That may be why she’s such an awful cook
sorry Ma
How come they’re not the boss of us? I’ve heard nobody shouting the “I, for one, welcome our new tetrachromat overlords” doodah.
Another interesting aspect of tetrachromacy, or any significant deviation in the spectral sensitivities of a person’s cone cells, is that it would completely change how color metamerism works for them. Simply put, metamerism is how a mixture of several discrete wavelengths can stimulate the eye in the same way as a completely different wavelength would, and it’s how we’re able to use three primary colors of light or pigment to recreate (most of) the visible spectrum. The standard light primaries of red, green, and blue align fairly well with the peak sensitivities of most people’s cones, but with different cones, the primaries would mix into completely different colors. Video images and color photos would look off, or potentially even completely wrong, because the colors wouldn’t “mix” the way they were supposed to. This is probably also the case for other species, so to your dog or cat, color TV probably has all different colors than real life.
That’s actually one of the ways they test for it. The examiner displays a spectral color. The teste is given four knobs that control the intensities of four spectral light sources which are combined and presented next to the challenge color. For trichromats, there will be an infinite set of solutions to the problem. If the tester has then try the same challenge twice, they are likely to come up with different solutions each time.
For a tetrachromat, they would have an exact solution and they would be able to reliably produce it when challenged with the same spectral color.
We suspect that my mother is a tetrachromat because both my brother and I are colorblind, but in different ways. Due to how the X chromosone provides green and red sensitive cones in the eyes, my brother and I should be the same kind of colorblind (or at least one of us not colorblind) if our mother was a trichromat. Since that’s not the case, our mother should be a tetrachromat. It’s theoretically possible to be a pentachromat–at least if you’re a woman.
Could be fun to do it with gene therapy. Then it wouldn’t be a sexist trait discriminating against males.
…and it could be used to see near-IR. All sorts of usefulness there.
Oh, geez, I just had a Gattaca moment there, shaddack. Imagine a future where no men are colorblind, but all women are pentachromats. Guess what, guys, you’re still colorblind! Doubly bad this time.
We still have the “fifty shades of yellow” moments. The tiles look exactly the same so pick the bloody matching ones yourself. And so on.
What I meant is a way to selectively modify the retinas themselves, possibly just after or before birth, so these traits are accessible to anybody, regardless of gender.
Or, move the genes to a different chromosome. No reason why the Y one couldn’t have some from the X one. Then we can address the germ line and won’t have to bother with doing the mods again generation after generation.
I had not heard the bit about a colorblind person doing better than a normal trichromat at assessing photos even if the photo is B/W. Maybe that exaplains why I do a good job taking B/W photos but my color photos are just ‘meh’. I had been leveraging my colorblindness without noticing it. Now, if I could just tell which light on the traffic controls is lit…
Okay, I like your future better than mine. Yes, you could put multiple different cone genes on any chromosone–there might be some practical limitations to that which I will leave to someone who knows genetics better than me.
This is sort of how the green and red genes came about. It’s theorized that the blue sensitive gene came first–animals were orthochromatic. Then, completely unrelated to that–or with the assistance of a virus–a red sensitive gene evolved. Much later, a transcription error caused that gene to be duplicated. Then, one of those coppies mutated and changed to be more green sensitive.
I bet there are cohorts of “bioethicists” and other do-gooders that would be quick to whine how wrong idea it is.
They are the reason why we cannot have nice things anytime soon.
A single color can be represented as a point in three-dimensional space where the x, y and z axes correspond to (for example) the amounts of red, green and blue light. The more similar two colors are, the shorter the distance between the points representing them. So you can measure the smallest difference between two colors that a person can distinguish as a distance D. Then, a spherical region of diameter D represents a single color to that person, since any two colors within that region will be indistinguishable to them. You can also measure the total volume of color space they are able to perceive (outside of which colors are either too dark or too bright to tell apart). Dividing the latter volume by the former gives you the maximum number of different colors they can distinguish, and I assume these are the numbers being talked about.
For tetrachromats (like birds) with cones sensitive to ultraviolet, the color space is actually four-dimensional, and so really does contain colors we can’t conceive of. Human tetrachromats’ fourth set of cones are sensitive to wavelengths within the same range as everyone else, so they still perceive a three-dimensional color space, but they can distinguish finer variations in the red-green plane.
In other words, they don’t see colors other people can’t see, they’re just better at telling similar shades apart. I too suspect that training your color perception makes a much bigger difference than having mutated eyeballs.
I would say that the space is not exactly a sphere. The sensors will have different sensitivity, so it will be some ellipsoid or, if they are nonlinear, some more complex potatoid shape.
No, no you don’t. the arrogance. The extra cone doesn’t access any part of the visible spectrum that regular folks can’t see or make non-visible parts visible (as in the mantis shrimp). Please show me something in a color i can’t see!!!
yep. this. better ability to see the variation of subtle differences in tones and shades, especially in low light.
it is an awesome mutation that allows one to have more sensitivity to colors and light. it increases the ability to pick out bits of color that the rest of us blend in with the surrounding color. it allows one to see the difference in two subtly different shades the rest of us would consider identical. It DOES NOT allow one to see colors that people without it cannot see (new or unique colors). What would the name of those colors be? where in the spectrum would they fall (aka wavelength)?
yes. this. she has a finer granularity of differentiation.
It’s a great super power, I feel sad for her that she can only use it 100 times though.
“I see colors you cannot perceive or imagine”
No need to be a dick about it…
When did you have a sense that you were different?
Concetta Antico: People who have been around me find it very obvious that this special vision ability, in combination with my own intelligence, has made me a little above other people.
Wouldn’t people who could only see red and blue say this same thing about us tri-chromats, if we tried to insist that “green” was not just another shade of magenta?
So how do you identify that extra cone or that you are a tetrachromat?
Are you Batman?
Actually, they’d kind of have a point. Early color film processes used only two colors, and it turns out that’s actually enough, albeit not as good. This image was produced with a teal/cyan separation, close to what you describe. You can still see green things in films shot that way, the colors are just less distinct.
In fact, the two-color Technicolor process used red and green, meaning it physically couldn’t record “blue” at all. Interestingly, you can still see blue skies, even though you’re looking at pale green, because there’s a lot more than spectroscopy involved in how we recognise color. The reason they used red and green, incidentally, is that we’re considerably more sensitive to variations in the green region than either blue or red.
Anyway the point is, color blind people don’t see a fundamentally different world to the rest of us-- that’s why there are special tests for color blindness, and you can grow to adulthood without even realising you have it-- and the difference between pure-blooded humans and tetrachromats is much less than that. Personally I don’t think we even need the camps, but better safe than sorry I guess.
