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PIT2
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Do blind people see blackness?
(and before u say, "no theyre blind", please think about it!)
(and before u say, "no theyre blind", please think about it!)
Yeah, same here. Its like asking "what do deaf people hear?" Completely blind people, can't see anything. Not even black.Hypnagogue said:My guess would be that blind people don't experience visual blackness, or anything in the visual modality for that matter. For instance, a better analogue for the visual experience of a blind person (at least one blind from birth, I'd imagine) might be not blackness, but rather, the same visual experience you have of the area in the back of your head. Blackness is a visual experience, even though it usually connotes absence of light. What you see at the back of your head is more like complete absence of any visual experience at all.
It's not necessarily that simple. The visual cortex requires proper visual inputs and motoric interactions in the world on the basis of that visual input in order to develop properly. In the absence of such input from birth, visual cortex proper would likely be subsumed for other perceptual/cognitive processes. I find it unlikely that such a radically different "visual" cortex would support anything like the subjective experience of vision (of which blackness is a type).PIT2 said:With 'the blind from birth' part, u mean that when one hasnt ever experienced light, then one still sees blackness but doesn't realize it because one can't compare it with light (since one can't imagine what light looks like).
For people who developed blindness well into life, it's likely that they at least have the capacity for visual experience. Whether or not they actually experience visual blackness or no visual phenomena at all, and how this unfolds as a function of time spent in blindness, is really an empirical question that would be best answered by asking for the introspective report of a suitable person. Whatever the answer turns out to be, though, a significant part of the story should be the physiological state of the brain regions that normally support visual experience. It's not just a matter of simple cognitive comparisons.And for people who have not been blind from birth, they can compare their no-light-blackness to their memories of once experienced light.
There are varying degrees of photosensitivity among animals. On different levels, you can actually trace the evolution of the mammalian eye. Some merely have mildly photosensitive patches of skin cells, more advanced types have crude retinae, others add a lens to the system, etc.. Insect compound eyes seem to be in a class by themselves, but I'm not sure.PIT2 said:And what about animals without any eyes, do they see blackness aswell?
Do plants?
hypnagogue said:For people who developed blindness well into life, it's likely that they at least have the capacity for visual experience. Whether or not they actually experience visual blackness or no visual phenomena at all, and how this unfolds as a function of time spent in blindness, is really an empirical question that would be best answered by asking for the introspective report of a suitable person. Whatever the answer turns out to be, though, a significant part of the story should be the physiological state of the brain regions that normally support visual experience. It's not just a matter of simple cognitive comparisons.
Well, there is no blackness behind our heads-- that was the point of my using that example. If you compare the visual experience of complete darkness to the visual experience of seeing out the back of your head, you should find that they are different, because the latter isn't a visual experience at all. You might think of it as analogous to the difference between the written numeral "0" as compared to the complete absence of any written number whatsoever. They may amount to roughly the same thing conceptually, but in one case there is a representational vehicle, a pointer which we interpret to mean "nothing," and in the other case there is literally nothing to begin with.PIT2 said:But is it (theoretically) possible for us, with our functioning visual cortex, to become visually aware of the blackness behind, below, above and besides our heads?
I've thought about it. Actually, I figured that one should come to the conclusion, "no, they're blind," after thinking about it, and not before.PIT2 said:Do blind people see blackness?
(and before u say, "no theyre blind", please think about it!)
i would rather consider it as not seeing at alldav2008 said:I imagine it would depend why they are blind. I don't know much about the reasons for blindness but I imagine it can either be caused by the eyes or by the brain.
If the eyes themselves are damaged then it would be the same as you being in a very dark room, that is no photons are hitting your eyes so the eyes don't send any signals to the brain and you "see" darkness.
If it's part of the brain that's damaged then I guess they wouldn't see anything. It would be as if they don't have the sense of sight at all.
PIT2 said:Do blind people see blackness?
(and before u say, "no theyre blind", please think about it!)