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This is rather more interesting from a machine learning point of view than philosophy. For instance, it seems a blind person does know about space from touch, b

This is rather more interesting from a machine learning point of view than philosophy. For instance, it seems a blind person does know about space from touch, but cannot innately identify space from visual information. What can we infer about the way our brains process sensory information from this fact?

theoh 12y ago
There's an interesting account here: http://www.richardgregory.org/papers/recovery_blind/recovery-from-early-blindness.doc http://www.richardgregory.org/papers/recovery_blind/recovery... which contains the following passage about a man who recovered his sight: "In view of his depressed state, we felt it best not to undertake formal tests. We did, however, ascertain that he was able to find his way about without the use of his eyes, and that he could detect the presence of houses and doors by the echoes from his footsteps. He was still fascinated by mirrors, and he still noted improvement in his ability to see. In particular, he said that he noted more and more the blemishes in things, and would examine small irregularities and marks in paint work or wood. Quite recently he had been struck by how objects changed their shape when he walked round them. He would look at a lamp post, walk round it, stand studying it from a different aspect, and wonder why it looked different and yet the same." I think the last line is interesting. There is a conflict between the spatial reconstruction and the optical appearance.
- raverbashing 12y ago
  This reminds me of trying to localize yourself using a very narrow field of vision, where you see things but it's hard to paint the picture of the environment (It may even be possible that the person has some kind of shortsightedness, I didn't see the article)
  - theoh 12y ago
    Yes. In fact there is a tradition in art theory of making a distinction between close vision (involving movement of the eye across a surface) and distant vision (in which the whole scene can be taken in at once). It's actually a fascinating bit of intellectual history, though I am not sure whether it counts as objective scientific knowledge. It started with the sculptor Adolf von Hildebrand and was developed by Alois Riegl into the notions of "haptic" and "optical" vision. Wolfflin then expanded that distinction into five polarities (linear vs painterly, plane vs recession, closed vs open, multiplicity vs unity, clarity vs complexity). In mathematical terms haptic seeing is concerned purely with manifold surfaces whereas the optical can also represent non-manifold geometry. Even more significance was later hung on that structure by the philosophers Walter Benjamin and Deleuze and Guattari. In particular the haptic is associated with surface, with smooth spaces of the mechanical, of trajectories and motion, while the optical is associated with volume, with striated spaces of the organic, of hierarchy and stasis. "parametric" vs. "implicit" if you like. It's a bit of a philosophical rabbit hole!
    - longingforlight 12y ago
      Ooooh. I never knew that there was this model of these different types of vision! I am a congenitally blind person who can (occasionally) find a way to make myself see a tiny bit better, and a lot of what I do is allow my eyes to wander up and down different surfaces. I basically pretend that they are fingertips. I am much less good at the other types of vision, but I've played around with them a bit; it's like I am hurling my body through space. I can't access the New Yorker article but I suspect my experience is different because I have always felt sighted even though I've never had vision. I really suck at being a blind person and thus am incredibly motivated to figure out how sight works, because I can already tell that I'm a visual learner (and an artist) and sight makes so much intrinsic sense to me.
otakucode 12y ago
For the blind, space and time are identical. The reason a blind person would imagine a typewriter 100 feet away as the same size as one 1 foot away is because the only time a blind person has ever experienced a typewriter at all is when it was at arms length. The idea of perspective is totally foreign to them. The connection between space and time comes from this extreme locality of the sensory world of the blind. If walking down a hallway, they can not perceive the end of it, and can only perceive the region they are currently in contact with. As they walk down the hallway, they learn that 2 seconds down there is a light fixture, 8 seconds down there is a bump in the carpet, and at 14 seconds the hallway ends. Intuitively, the concepts become very strongly linked. Oliver Sacks discusses this in some of his books. I think the most informative thing about this is that it is completely consistent with a view of the brain as an associative engine - stimulus which occurs together gets associated with each other, and presence of one stimulates an expectation of the others.
- longingforlight 12y ago
  Wow, I am blind, and I am very very not good at this way of thinking, as evidenced by the fact that it is very difficult for me to learn routes from point a to point b based on this type of info. What's more helpful to me is imagining my line of travel and focusing how my body aligns with different landmarks.

theoh 12y ago

There's an interesting account here: http://www.richardgregory.org/papers/recovery_blind/recovery-from-early-blindness.doc http://www.richardgregory.org/papers/recovery_blind/recovery... which contains the following passage about a man who recovered his sight: "In view of his depressed state, we felt it best not to undertake formal tests. We did, however, ascertain that he was able to find his way about without the use of his eyes, and that he could detect the presence of houses and doors by the echoes from his footsteps. He was still fascinated by mirrors, and he still noted improvement in his ability to see. In particular, he said that he noted more and more the blemishes in things, and would examine small irregularities and marks in paint work or wood. Quite recently he had been struck by how objects changed their shape when he walked round them. He would look at a lamp post, walk round it, stand studying it from a different aspect, and wonder why it looked different and yet the same." I think the last line is interesting. There is a conflict between the spatial reconstruction and the optical appearance.

raverbashing 12y ago
This reminds me of trying to localize yourself using a very narrow field of vision, where you see things but it's hard to paint the picture of the environment (It may even be possible that the person has some kind of shortsightedness, I didn't see the article)
- theoh 12y ago
  Yes. In fact there is a tradition in art theory of making a distinction between close vision (involving movement of the eye across a surface) and distant vision (in which the whole scene can be taken in at once). It's actually a fascinating bit of intellectual history, though I am not sure whether it counts as objective scientific knowledge. It started with the sculptor Adolf von Hildebrand and was developed by Alois Riegl into the notions of "haptic" and "optical" vision. Wolfflin then expanded that distinction into five polarities (linear vs painterly, plane vs recession, closed vs open, multiplicity vs unity, clarity vs complexity). In mathematical terms haptic seeing is concerned purely with manifold surfaces whereas the optical can also represent non-manifold geometry. Even more significance was later hung on that structure by the philosophers Walter Benjamin and Deleuze and Guattari. In particular the haptic is associated with surface, with smooth spaces of the mechanical, of trajectories and motion, while the optical is associated with volume, with striated spaces of the organic, of hierarchy and stasis. "parametric" vs. "implicit" if you like. It's a bit of a philosophical rabbit hole!
  - longingforlight 12y ago
    Ooooh. I never knew that there was this model of these different types of vision! I am a congenitally blind person who can (occasionally) find a way to make myself see a tiny bit better, and a lot of what I do is allow my eyes to wander up and down different surfaces. I basically pretend that they are fingertips. I am much less good at the other types of vision, but I've played around with them a bit; it's like I am hurling my body through space. I can't access the New Yorker article but I suspect my experience is different because I have always felt sighted even though I've never had vision. I really suck at being a blind person and thus am incredibly motivated to figure out how sight works, because I can already tell that I'm a visual learner (and an artist) and sight makes so much intrinsic sense to me.

otakucode 12y ago

For the blind, space and time are identical. The reason a blind person would imagine a typewriter 100 feet away as the same size as one 1 foot away is because the only time a blind person has ever experienced a typewriter at all is when it was at arms length. The idea of perspective is totally foreign to them. The connection between space and time comes from this extreme locality of the sensory world of the blind. If walking down a hallway, they can not perceive the end of it, and can only perceive the region they are currently in contact with. As they walk down the hallway, they learn that 2 seconds down there is a light fixture, 8 seconds down there is a bump in the carpet, and at 14 seconds the hallway ends. Intuitively, the concepts become very strongly linked. Oliver Sacks discusses this in some of his books. I think the most informative thing about this is that it is completely consistent with a view of the brain as an associative engine - stimulus which occurs together gets associated with each other, and presence of one stimulates an expectation of the others.

longingforlight 12y ago
Wow, I am blind, and I am very very not good at this way of thinking, as evidenced by the fact that it is very difficult for me to learn routes from point a to point b based on this type of info. What's more helpful to me is imagining my line of travel and focusing how my body aligns with different landmarks.