3 ms·

Not necessarily. There is a lot of analog in the eyes beyond the nerves, and we don't know all the effects of ambient light on the entire eye structure. Even if

by bdamm 6y ago

Not necessarily. There is a lot of analog in the eyes beyond the nerves, and we don't know all the effects of ambient light on the entire eye structure. Even if the neural impulses end up being similar (and I doubt that) the eye as a whole organ may not respond the same way. Maybe that heat energy triggers something in the cornea? We don't know.

mattkrause 6y ago
I don't disagree that UV and IR exposure may be important. Variations in UV exposure are thought to account for changing rates of myopia, for example. There may be non-image-forming receptors with different spectral sensitivities for circadian rhythms. However, the structure and function of circuits involved in color representations has been studied to death, and it overwhelmingly points to a tristimulus model where the activation of the S/M/L cones matters, rather than the complete power spectrum of the illuminant. The sensitivity of rods and cones has measured measured with exquisite sensitivity, both behaviorally and by directly recording their electrical activity. Many downstream neurons in visual cortex get their input from individual L/M cones (parvocellular pathway). The others (magno, konio) have a fairly simple mix of inputs from a simple, spatially organized combination of the cones. In some cases (especially within the retina), the individual fibers have been traced and mapped. There is a hell of a lot we don't know about the brain, but the very early representation of color isn't one of them. If you've got sources saying otherwise, I'd love to see them.
- mattkrause 6y ago
  (This may come off a bit harsher than I meant. It's just that I'm surprised to hear someone doubt what I thought was a well-established principle with lots of data behind it. If you do have anything suggesting otherwise, I'd legitimately love to read it. If not, WebVision is an excellent resource with a long chapter about color. https://webvision.med.utah.edu/book/part-vii-color-vision/color-vision/ https://webvision.med.utah.edu/book/part-vii-color-vision/co... The Visual Neurosciences is a behemoth too, if you can find a copy; I don't think it's online.
heavenlyblue 6y ago
We also can’t prove the absence the magical wardrobe with an entrance to Narnia from our universe, yet many people would say you are insane if you think it’s true.

by bdamm 6y ago

mattkrause 6y ago

I don't disagree that UV and IR exposure may be important. Variations in UV exposure are thought to account for changing rates of myopia, for example. There may be non-image-forming receptors with different spectral sensitivities for circadian rhythms. However, the structure and function of circuits involved in color representations has been studied to death, and it overwhelmingly points to a tristimulus model where the activation of the S/M/L cones matters, rather than the complete power spectrum of the illuminant. The sensitivity of rods and cones has measured measured with exquisite sensitivity, both behaviorally and by directly recording their electrical activity. Many downstream neurons in visual cortex get their input from individual L/M cones (parvocellular pathway). The others (magno, konio) have a fairly simple mix of inputs from a simple, spatially organized combination of the cones. In some cases (especially within the retina), the individual fibers have been traced and mapped. There is a hell of a lot we don't know about the brain, but the very early representation of color isn't one of them. If you've got sources saying otherwise, I'd love to see them.

mattkrause 6y ago
(This may come off a bit harsher than I meant. It's just that I'm surprised to hear someone doubt what I thought was a well-established principle with lots of data behind it. If you do have anything suggesting otherwise, I'd legitimately love to read it. If not, WebVision is an excellent resource with a long chapter about color. https://webvision.med.utah.edu/book/part-vii-color-vision/color-vision/ https://webvision.med.utah.edu/book/part-vii-color-vision/co... The Visual Neurosciences is a behemoth too, if you can find a copy; I don't think it's online.

heavenlyblue 6y ago

We also can’t prove the absence the magical wardrobe with an entrance to Narnia from our universe, yet many people would say you are insane if you think it’s true.