Color Vision 7: Primate Color Vision

Primates have unique Color Vision status. Old World Primates, eg. humans and apes, have 3 color cones. New World Primates have variable Cone colors; 2/3 of females have 3 colors; the 1/3 and males have 2 colors. How to explain that variability and most likely how it got that way.

[@cbeyedr]

Thank you for the kind comment. I also find all of this exciting, compelling, worth sharing.

[@MikkoRantalainen]

Great video! Could you also add the list of references to the description instead of having those only in video as image?

[@missyerica3577]

I’m interested to know more about the type of vision cows, pigs, and deer have, but I’m not surprised it wasn’t mentioned. He didn’t want to make people uncomfortable by showing that the food they eat sees the same world as them. Exceptionally too, as most mammals are dichromats.

[@DANGJOS]

So fascinating!! It must be weird having some members of your species seeing different colors than others.

[@cbeyedr]

Thank you for the note. The deeper explanation was beyond the scope and purpose of that series, aimed at a general audience.
Am not sure what you mean by less light, are you referring to the dark current?
Photons are absorbed by Rhodopsin, (activating Transducin, PDE, reducing cGMP), causing cGMP gated calcium channels to close, thereby hyper-polarizing the photo-receptor, which affects frequency of spike activity in downstream neurons, signalling light.
As it happens, am currently writing a retina series that will address that level of detail in photo-transduction and retinal structure. Stay tuned.

[@MisterrLi]

Craig Blackwell Hi, I will stay tuned for sure!
What I meant was that signals are produced when the building up occurs of the opsins.
Anyway, the eye as a whole is indeed very complex. If you take into account the fill-in functions of the eye/brain (actually many functions) observed in stabilized retinal images and the blind spot for example, combined with the interaction of the microsaccades with the neural network in the eye, it is clear that what is actually causing signals to leave the eye is a moving difference of radiation in the retina, normally caused by a combination between the microsaccades and the retinal neural network. I realize this is not a common explanation in most text books on vision, but it is the most logical one considering all the evidence we have for these visual effects.
Very interesting and complicated stuff indeed. I am though mostly researching color vision using psychophysics and similar methods, making computer color models for perceptual spaces. It has led to some interesting results which I will publish soon, that can help us making computer color systems more "tuned" to our perceptual dimensions (instead of the very non-perceptual Red, Green and Blue).

[@sohowsoon6652]

a home run
deep in to the left field of the universe

[@MisterrLi]

Hi Craig! Nice series. But... it is wrong in the explanation of the basics of color vision. In fact it works quite opposite of this (very popular but wrong) explanation. It is actually when there is LESS light coming in a signal is triggered. And it is of course much more complicated than that, with a layer of signal processing in the retina before the actual signal goes away reaching the brain. And the effects of movements of the eye is also significant in the process, combined with fill-in effects for the blind spot in the brain. Please correct this part, I'm sure this is simple to get right, and we would all benefit in a richer knowledge!