
What’s a Tetrachromat? Meet a Person Who Sees 100M Colors - shawndumas
https://upvoted.com/2015/12/04/whats-a-tetrachromat-meet-a-person-who-sees-100-million-colors/
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amluto
I'm having trouble imagining how an extra cone in between red and green
results rainbows and the like around the moon. I would expect the spectrum of
light forward-scattered as moonlight propagates through the atmosphere to be
constant over small angular shifts. I'd also expect the more interesting
changes to be in the shorter-wavelength range, and the common tetrachromat
theory (normal vision plus deuteranomaly) shouldn't have much effect at
shorter wavelengths.

Anyone who likes calculating scattering coefficients or who has an appropriate
spectrometer should be able to check this.

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earlz
I think you'd have to think about things differently. Imagine the people with
only 2 cones... Now imagine if everyone only had two cones "I can't imagine
how adding an extra cone would allow you to see these different colors in
trees and the sky, cause there aren't any colors between blue and yellow".
Color is a weird topic anyway because it is impossible to determine that
everyone actually sees the same thing (which could explain why people have
different color preferences).

There are wavelengths that each cone responds to. I'm not sure that there has
been any research into the matter, but I imagine that this fourth cone adds a
response to a wavelength either below or above normal visible range, or maybe
more likely a person with 4 cones actually has less less frequency response by
the other 3 cones, and the 4th cone fills in the gap, allowing for not really
more frequency response, but rather just more specific.. And then with the
magic of the brain, who knows how that enhanced response ends up being
interpreted

And finally, when she paints to recreate what she sees, I imagine that paint
is much more lively to her than what we are actually seeing.. which is a weird
paradoxical thought experiment in itself

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amluto
The standard idea is that the fourth type of cone is the anomalous type
inherited from one's father. In the most common cases (deuteranomaly), it
fills in between red and green.

In any event, while color perception is certainly subjective, both the
underlying spectrum and the eye's physiological response are very much
measurable.

An interesting experiment would be to see whether she could construct two
paints that she can tell apart but that look identical to everyone else.

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puredemo
Article states that she hasn't even been tested to verify she is
tetrachromatic.

Seems like pretty basic due diligence to complete before submitting an article
with this title.

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ctdonath
Perhaps you should read the short story "The Country of the Blind" by HG
Wells. [http://www.online-literature.com/wellshg/3/](http://www.online-
literature.com/wellshg/3/) To wit: a society generally lacking in a sense
thinks those with that extra sense insane.

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RogerL
Who is claiming she is insane? She has the gene for it, the question is is she
actually seeing these colors.

Seems easy to test. You can test if I see reds, for example, even if you are
color blind. Example: here's a rose petal that she says has many colors but we
see one. Have her draw it and label it (not paint it, as not everyone can
paint). Now give that same petal to another person that claims this power.
Have them draw and label it. If their color maps agree, they are sensing
something. If not, well, it requires more study. Seems pretty basic unless I
am missing something.

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ctdonath
The point is that people with such senses find it utterly obvious that they
do, while those without are incredulous - and demanding proof - that they do.
Such proof is hard to satisfactorily address (as elaborated on in the Wells
story), seems needlessly overwrought to those being tested, and all too often
is nonetheless dismissed anyway by those without.

If you haven't read the Wells story, it may behoove you to do so before
criticizing my post further. The point is largely addressed. And sorry if the
word "insane" bothered you; seems a proper use given that the implication is
she's claiming a "power" which others here are disputing (if she doesn't have
it, seems the term applies).

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sosuke
How would you categorize this content? It is a unique post that links to
Reddit which in turn links to a different article from a couple of days ago
[http://nymag.com/scienceofus/2015/02/what-like-see-a-
hundred...](http://nymag.com/scienceofus/2015/02/what-like-see-a-hundred-
million-colors.html)

~~~
Smushman
More of a 'throw it up there and see what sticks' versus something thought was
thought out.

Thanks for the background info.

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morb
Years ago Radiolab did an episode on colors:
[http://www.radiolab.org/story/211119-colors/](http://www.radiolab.org/story/211119-colors/)

In the second segment they introduce a potential tetrachromat, Susan Hogan
(not the same person as this article). I don't remember if her tetrachromacy
was confirmed a real science experiment, I don't think it was.

But I'd still recommend the whole episode. All three segments were pretty
interesting.

