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What’s a Tetrachromat? Meet a Person Who Sees 100M Colors

12 points by shawndumas 11y ago

puredemo 11y ago
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.
- ctdonath 11y ago
  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.
  - RogerL 11y ago
    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.
    - murbard2 11y ago
      Much more precise as well as much more simple: test whether or not she is able to distinguish some wavelength from any combination of red, green and blue.
    - ctdonath 11y ago
      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).
sosuke 11y ago
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-million-colors.html http://nymag.com/scienceofus/2015/02/what-like-see-a-hundred...
- Smushman 11y ago
  More of a 'throw it up there and see what sticks' versus something thought was thought out. Thanks for the background info.
amluto 11y ago
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.
- earlz 11y ago
  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
  - amluto 11y ago
    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.
morb 11y ago
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.

12 points by shawndumas 11y ago

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.

ctdonath 11y ago
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.
- RogerL 11y ago
  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.
  - murbard2 11y ago
    Much more precise as well as much more simple: test whether or not she is able to distinguish some wavelength from any combination of red, green and blue.
  - ctdonath 11y ago
    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).

sosuke 11y ago

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-million-colors.html http://nymag.com/scienceofus/2015/02/what-like-see-a-hundred...

Smushman 11y ago
More of a 'throw it up there and see what sticks' versus something thought was thought out. Thanks for the background info.

amluto 11y ago

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.

earlz 11y ago
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
- amluto 11y ago
  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.

morb 11y ago

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.