1 upvotes, 2 direct replies (showing 2)
View submission: Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology
Suppose we have a strong deutan in his mid-to-late 20s called Tyler. Tyler's M-cones are missing/defective in both eyes, so he has never been able to see colour "normally".
Would replacing/fixing his cones allow him to see new colours, or would he have not been exposed to those colours in time to be able to distinguish them properly? Would the connections that would have allowed him to distinguish, say, blue from purple have died off, or would Tyler now be able to see purple (and all the other colours he did not previously perceive)?
Essentially, is colour in the eye or in the brain? And could Tyler's brain now perceive purple?
Comment by Mockingjay40 at 18/01/2024 at 22:04 UTC
2 upvotes, 0 direct replies
Not my field, but as far as I understand, if we were able to fix the cones, I'd imagine the brain would be able to perceive the colors, as the human brain is not defective in color-blindness (to my knowledge at the very least). The conceptual idea of "color" is a human concept, because it is the brain's perception of certain wavelengths of light after they've been processed by the human eye, so my initial thought would be that replacing the cones would restore the ability to perceive that wavelength normally. I'd imagine it might result in some distress or confusion at first, since it would be difficult to adjust to though. So the brain very well might perceive these colors as less vibrant even after restoring the cones. I wouldn't be surprised if that were the case. This speculation makes sense to me, but don't take what I've said as law. I'd need to look more into it to know for certain
Comment by Indemnity4 at 19/01/2024 at 01:38 UTC
2 upvotes, 1 direct replies
The experiment has been done in monkeys via injecting viruses into their eyes for grow or turn on cones.
All *male* squirrel monkeys are colourblind. They only have 2 functioning cones of the 3 required for colour vision.
A few weeks after receiving a gene therapy the male squirrel monkeys could distinguish the new colours. They could see colours they never could before. Their brain adapted to the new sensory input.
A few human relatable situations.
There are people with red-green colour blindness that cannot distinguish between the two. You can buy special glasses that filter some middle wavelengths. Let's some subset of colour-blind people "perceive" those colours for the first time. In this case we are taking information away from the brain in order to improve perception.
Lots and lots and lots of preventable blindness issues. Someone can have a cornea replaced and "see" colour for the first time. Someone can have laser eye surgery which thins the lens, such that they can now see more "blue" and even into UV range. For the Lasik people, they mostly report it as pain or flashes, it's not useful information.