6 ms·

Molyneux's problem

44 points by mike_esspe 13y ago

drblast 13y ago
Wow, that's really cool. Now I have an additional question. Assume at one point you were able to see and touch things, then lost your sight, then regained it. I'd think that while blind, you'd still try to form images of things you touched, and then be able to recognize them after your sight was recovered. If that's true, then the connection between the senses would not be fundamentally impossible, but rather a learned behavior.
jere 13y ago
>In 2003, Pawan Sinha, a professor at MIT in Boston, set up a program in India as a part of which he treated 5 patients that almost instantly took them from total congenital blindness to fully seeing.[8][9] This provided a unique opportunity or answer the Molyneux's problem experimentally. Based on this study, on April 10, 2011, he concluded that the answer, in short, to Molyneux's problem was "no". Although after restoration of sight, the subjects could distinguish between objects visually as effectively as they would do by touch alone, they were unable to form the connection between object perceived using the two different senses. That is a really counterintuitive result for me. I always assumed that one could construct a spatial model of something by touching it, without that directly being related to vision.
- Shinkei 13y ago
  I think that's why the problem is so interesting and the answer so telling about the human brain. The way I picture it is that if you closed your eyes and held a ball, you would picture a sphere... but it is because you have in internalized image of a sphere. If you had never seen a sphere, you probably wouldn't be able to imagine one... even if you could feel all it's dimensions. Your mental 'canvas' is not only lacking paints... you don't even have a brush.
- andrewflnr 13y ago
  You'd think, because it all boils down to coordinates, right? Or at least relative coordinates. Apparently not. It's more like pattern matching, where the patterns are much more abstract than a coordinate system, where the connection between felt and seen patterns has to be learned, and the translation of either into "coordinates" has to be consciously worked at. I don't really know, not being anything like a neuroscientist. I'm also reminded of the way babies are born seeing upside down, and learn naturally to invert their vision. Apparently if one wears glasses that invert their vision, it eventually flips back. Is that a built-in transformation, or is it deduced from first principles, just to make a simpler mapping between seen data and other data, e.g., to more simply reconcile feeling your hand move one direction and watching it move in another? If from first principles, what else is it doing? And we know the brain adds stuff to the picture before it's presented to the conscious mind, too.
  - raldi 13y ago
    > I'm also reminded of the way babies are born seeing upside down Do you have a source for that?
    - Houshalter 13y ago
      I believe he means that the light receptors on your eye are inverted like this: http://www.northlight-images.co.uk/content_images_2/digital_pinhole/pinhole_geometry_2.gif http://www.northlight-images.co.uk/content_images_2/digital_... But the idea that people "see upside-down" is a common misconception. How the inputs map onto your brain spatially don't really matter. Well they do, but it doesn't matter if it's inverted or not because your brain learns (or likely is hardwired biologically) to map signals that come from the bottom to being located at "top" and signals that come from the top as "bottom".
      - andrewflnr 13y ago
        Right, it's precisely that learning I'm interested in. I could well be wrong in that specific example. IIRC, I first got that from one of those "science" books for kids.
- StavrosK 13y ago
  You probably can. You can't construct a spatial model of something by seeing it unless you've already gotten used to the various effects (perspective, parallax, etc) and how they represent space, though. Or, at least, that's my totally untrained opinion.
- shmageggy 13y ago
  You absolutely can, and there's even been recent research into the computational mechanisms that are behind this kind of inference [1]. They build a computational model that learns spatial/visual representation from (simulated) haptic stimuli with performance similar to human subjects. I think the reason Sinha's experiment had a negative result was, as other commenters have mentioned, that this ability is a learned behavior. Those who are blind from birth simply never developed the ability to form abstract representations from visual stimuli, therefore haptic information cannot be translated into these visual representations. The other commenters who are saying there is no pathway between the two modalities are wrong, and it's easy to set up an experiment to show it. Just blindfold someone and hand them an unfamiliar object, then, without showing it to them, have them draw it. It's clear that we can do this to some extent. [1] http://www.bcs.rochester.edu/people/robbie/jacobslab/abstracts.html#Yildirim13 http://www.bcs.rochester.edu/people/robbie/jacobslab/abstrac...
  - w1ntermute 13y ago
    Right, there is a physical difference between the brain of a person who has been blind from birth and someone who has not. This also means that if you restore sight to someone who once had it and then lost it, they should have no trouble picking out an object they hadn't seen (only felt), even if it was an object they had neither seen nor felt prior to losing their vision.
- hcarvalhoalves 13y ago
  > I always assumed that one could construct a spatial model of something by touching it, without that directly being related to vision. You can do that if you are able to see, close your eyes and touch it. What you'll be doing is seeing "in the mind's eye". Someone might have researched that, but you'll probably be exercising some cortex area related to vision. Apparently, for people born blind, they can't make that connection since they don't have the experience to draw from. I would think it's like singing two songs one octave apart and asking someone who was deaf which had a higher pitch. Even though he can hear, he wouldn't have this intuition developed yet.
chm 13y ago
The problem is fascinating in itself, but I don't see why it is classified as an unsolved problem in philosophy. From the article: "The resolution of this problem is in some sense provided by the study of human subjects who gain vision after extended congenital blindness." The solution is purely empirical, not philosophical. https://en.wikipedia.org/wiki/Unsolved_problems_in_philosophy https://en.wikipedia.org/wiki/Unsolved_problems_in_philosoph...
- arrrg 13y ago
  Philosophical problems tend to turn into empirical problems with time. That’s completely normal. At some point in time you can’t actually investigate something empirically, so it’s a philosophical problem. As soon as you can, the philosophical problem turns into an empirical one.
  - Houshalter 13y ago
    I don't understand how it's a philosophical question. It's a question about the state of reality. Even before anyone tried to actually test it, it was still a question about the way things are. It's like asking what's inside a room, and calling it a philosophical question. Then you open the door and actually look and suddenly it's not?
    - saraid216 13y ago
      The Schroedinger's Cat thought experiment is definitely a philosophical problem, yes.
    - arrrg 13y ago
      Yes, that’s how it works, basically. Only that at the time you are asking the question, it has to actually be impossible to find out what’s inside the room. Philosophy is for questions that cannot be investigated empirically. And that includes those that cannot yet be investigated empirically. That’s definitely where I see the role of philosophy.
    - jleader 13y ago
fsckin 13y ago
This reminded me of a feature of Esref Armagan, a blind Turkish painter, who was never sighted. Skip to 7 minutes to see him paint a building he's never been to before, with 100% correct perspective. http://www.dailymotion.com/video/x9ig6p_esref-armagan-blind-painter_creation#.UXxhv0BDuzA http://www.dailymotion.com/video/x9ig6p_esref-armagan-blind-...
- cantos 13y ago
  I wonder if he was given sight and at the same given two paintings of a scene, one his and another by someone else if he would be able to tell the difference.
EGreg 13y ago
I expected to read about Peter Molyneux's problem of producing and selling games he dreams up around strange concepts, which I thought became so well known that it got an official name and put in Wikipedia. But this was more interesting !
refrigerator 13y ago
I think that if the previously blind person analyses the shapes in the right way, they'd be able to tell which one is the sphere and which one is the cube: The only things the person would be able to gain from just touching the objects is that the sphere is "the same all over" and the cube is "not the same all over", to dumb it down considerably. If the newly unblind man looks at the objects in a similar way and considers symmetry, I think he would be able to tell that one is infinitely more symmetrical than the other and would be able to deduce that the shape that looks the same all over would be the sphere. Does that make sense?
kcl 13y ago
With respect to Molyneux and Locke, while I believe they get the general idea right, I believe they get the actual answer wrong. The answer to Molyneux's problem should be "yes" --- the newly sighted can correctly associate the shapes. A sufficiently educated and intelligent person with congenital blindness would be able to correctly differentiate the shapes. Say, for instance, had Locke been born blind and still educated as rigorously. Of the many deductions that could be performed, the motion of the head with eyes fixed looking around the border of an object in space approximates the motion of the hand tracing the same object. Many other deductions are possible. All you need are reasonable assumptions about the acclimatization process, e.g., the patient can have a suitable amount of time to adjust to being sighted but cannot touch anything during the process. It is fascinating to think about the idea of disconnected senses, but as so commonly happens, fascination with an idea leads to sloppy thinking, especially among the educated. The reason why the empirical studies of the patients from India are wrong, despite being interpreted as giving a concurring answer, is that the blind have traditionally been given feeble educations, lacking in the type of rigorous thinking necessary to solve the problem. Historically it was challenging to teach abstract reasoning to the blind, and for this reason many were not taught. See Herzog's documentary "Handicapped Future" for tragic examples in relatively wealthy 1960s West Germany. http://en.wikipedia.org/wiki/Handicapped_Future http://en.wikipedia.org/wiki/Handicapped_Future The five patients in India who could not afford simple but life-altering surgery were sure to be poor in addition to being blind, and so surely must have received awful educations. Compounding this are their young ages. A sufficiently motivated, newly-sighted Locke would've gotten the answer correct.
- xwowsersx 13y ago
  I'm confused...Locke and Molyneux weren't saying the newly sighted person wouldn't be able to distinguish between the shapes, but that they wouldn't be able to synchronize that distinction with their touch sensations. In other words, they wouldn't be able to identify which was the one they identified, by touch, as spherical and which as square.
  - ramchip 13y ago
    I do think that's what the poster is referring to: > the motion of the head with eyes fixed looking around the border of an object in space approximates the motion of the hand tracing the same object His argument is that this kind of abstract reasoning would be mostly developed by education, so people with very little education would not be able to associate the shapes they see with those they touched.
twelvechairs 13y ago
Surely this is not a hypothetical anymore or one with merely one test case - see http://en.wikipedia.org/wiki/Visual_prosthesis http://en.wikipedia.org/wiki/Visual_prosthesis for example. It seems obvious to me that it takes some time for people to get used to using a new sense - particularly for higher-order abilities. Differentiating 'round' from 'hard edged' is probably a fairly simplistic function which your brain should be able to quickly figure out, but I don't see how it can just be instant.
- kenko 13y ago
  I think this is exactly right. Tactile visual substitution systems provide a sensory modality that we may as well call sight, just not via the eyeballs, and it takes time for the blind to become capable with them. Why wouldn't it take time for them to become capable with a sensory modality that is causally associated with the eyeballs? And in fact, it does take time.
kenko 13y ago
http://plato.stanford.edu/entries/molyneux-problem/ http://plato.stanford.edu/entries/molyneux-problem/
Siecje 13y ago
I say yes. If you asked a blind person to draw a sphere they would draw a circle, if you asked them to draw a cube they would draw a square.

44 points by mike_esspe 13y ago

Wow, that's really cool. Now I have an additional question. Assume at one point you were able to see and touch things, then lost your sight, then regained it. I'd think that while blind, you'd still try to form images of things you touched, and then be able to recognize them after your sight was recovered. If that's true, then the connection between the senses would not be fundamentally impossible, but rather a learned behavior.

jere 13y ago

>In 2003, Pawan Sinha, a professor at MIT in Boston, set up a program in India as a part of which he treated 5 patients that almost instantly took them from total congenital blindness to fully seeing.[8][9] This provided a unique opportunity or answer the Molyneux's problem experimentally. Based on this study, on April 10, 2011, he concluded that the answer, in short, to Molyneux's problem was "no". Although after restoration of sight, the subjects could distinguish between objects visually as effectively as they would do by touch alone, they were unable to form the connection between object perceived using the two different senses. That is a really counterintuitive result for me. I always assumed that one could construct a spatial model of something by touching it, without that directly being related to vision.

Shinkei 13y ago
I think that's why the problem is so interesting and the answer so telling about the human brain. The way I picture it is that if you closed your eyes and held a ball, you would picture a sphere... but it is because you have in internalized image of a sphere. If you had never seen a sphere, you probably wouldn't be able to imagine one... even if you could feel all it's dimensions. Your mental 'canvas' is not only lacking paints... you don't even have a brush.
andrewflnr 13y ago
You'd think, because it all boils down to coordinates, right? Or at least relative coordinates. Apparently not. It's more like pattern matching, where the patterns are much more abstract than a coordinate system, where the connection between felt and seen patterns has to be learned, and the translation of either into "coordinates" has to be consciously worked at. I don't really know, not being anything like a neuroscientist. I'm also reminded of the way babies are born seeing upside down, and learn naturally to invert their vision. Apparently if one wears glasses that invert their vision, it eventually flips back. Is that a built-in transformation, or is it deduced from first principles, just to make a simpler mapping between seen data and other data, e.g., to more simply reconcile feeling your hand move one direction and watching it move in another? If from first principles, what else is it doing? And we know the brain adds stuff to the picture before it's presented to the conscious mind, too.
- raldi 13y ago
  > I'm also reminded of the way babies are born seeing upside down Do you have a source for that?
  - Houshalter 13y ago
    I believe he means that the light receptors on your eye are inverted like this: http://www.northlight-images.co.uk/content_images_2/digital_pinhole/pinhole_geometry_2.gif http://www.northlight-images.co.uk/content_images_2/digital_... But the idea that people "see upside-down" is a common misconception. How the inputs map onto your brain spatially don't really matter. Well they do, but it doesn't matter if it's inverted or not because your brain learns (or likely is hardwired biologically) to map signals that come from the bottom to being located at "top" and signals that come from the top as "bottom".
    - andrewflnr 13y ago
      Right, it's precisely that learning I'm interested in. I could well be wrong in that specific example. IIRC, I first got that from one of those "science" books for kids.
StavrosK 13y ago
You probably can. You can't construct a spatial model of something by seeing it unless you've already gotten used to the various effects (perspective, parallax, etc) and how they represent space, though. Or, at least, that's my totally untrained opinion.
shmageggy 13y ago
You absolutely can, and there's even been recent research into the computational mechanisms that are behind this kind of inference [1]. They build a computational model that learns spatial/visual representation from (simulated) haptic stimuli with performance similar to human subjects. I think the reason Sinha's experiment had a negative result was, as other commenters have mentioned, that this ability is a learned behavior. Those who are blind from birth simply never developed the ability to form abstract representations from visual stimuli, therefore haptic information cannot be translated into these visual representations. The other commenters who are saying there is no pathway between the two modalities are wrong, and it's easy to set up an experiment to show it. Just blindfold someone and hand them an unfamiliar object, then, without showing it to them, have them draw it. It's clear that we can do this to some extent. [1] http://www.bcs.rochester.edu/people/robbie/jacobslab/abstracts.html#Yildirim13 http://www.bcs.rochester.edu/people/robbie/jacobslab/abstrac...
- w1ntermute 13y ago
  Right, there is a physical difference between the brain of a person who has been blind from birth and someone who has not. This also means that if you restore sight to someone who once had it and then lost it, they should have no trouble picking out an object they hadn't seen (only felt), even if it was an object they had neither seen nor felt prior to losing their vision.
hcarvalhoalves 13y ago
> I always assumed that one could construct a spatial model of something by touching it, without that directly being related to vision. You can do that if you are able to see, close your eyes and touch it. What you'll be doing is seeing "in the mind's eye". Someone might have researched that, but you'll probably be exercising some cortex area related to vision. Apparently, for people born blind, they can't make that connection since they don't have the experience to draw from. I would think it's like singing two songs one octave apart and asking someone who was deaf which had a higher pitch. Even though he can hear, he wouldn't have this intuition developed yet.

chm 13y ago

The problem is fascinating in itself, but I don't see why it is classified as an unsolved problem in philosophy. From the article: "The resolution of this problem is in some sense provided by the study of human subjects who gain vision after extended congenital blindness." The solution is purely empirical, not philosophical. https://en.wikipedia.org/wiki/Unsolved_problems_in_philosophy https://en.wikipedia.org/wiki/Unsolved_problems_in_philosoph...

arrrg 13y ago
Philosophical problems tend to turn into empirical problems with time. That’s completely normal. At some point in time you can’t actually investigate something empirically, so it’s a philosophical problem. As soon as you can, the philosophical problem turns into an empirical one.
- Houshalter 13y ago
  I don't understand how it's a philosophical question. It's a question about the state of reality. Even before anyone tried to actually test it, it was still a question about the way things are. It's like asking what's inside a room, and calling it a philosophical question. Then you open the door and actually look and suddenly it's not?
  - saraid216 13y ago
    The Schroedinger's Cat thought experiment is definitely a philosophical problem, yes.
  - arrrg 13y ago
    Yes, that’s how it works, basically. Only that at the time you are asking the question, it has to actually be impossible to find out what’s inside the room. Philosophy is for questions that cannot be investigated empirically. And that includes those that cannot yet be investigated empirically. That’s definitely where I see the role of philosophy.
  - jleader 13y ago

fsckin 13y ago

This reminded me of a feature of Esref Armagan, a blind Turkish painter, who was never sighted. Skip to 7 minutes to see him paint a building he's never been to before, with 100% correct perspective. http://www.dailymotion.com/video/x9ig6p_esref-armagan-blind-painter_creation#.UXxhv0BDuzA http://www.dailymotion.com/video/x9ig6p_esref-armagan-blind-...

cantos 13y ago
I wonder if he was given sight and at the same given two paintings of a scene, one his and another by someone else if he would be able to tell the difference.

EGreg 13y ago

I expected to read about Peter Molyneux's problem of producing and selling games he dreams up around strange concepts, which I thought became so well known that it got an official name and put in Wikipedia. But this was more interesting !

refrigerator 13y ago

I think that if the previously blind person analyses the shapes in the right way, they'd be able to tell which one is the sphere and which one is the cube: The only things the person would be able to gain from just touching the objects is that the sphere is "the same all over" and the cube is "not the same all over", to dumb it down considerably. If the newly unblind man looks at the objects in a similar way and considers symmetry, I think he would be able to tell that one is infinitely more symmetrical than the other and would be able to deduce that the shape that looks the same all over would be the sphere. Does that make sense?

kcl 13y ago

With respect to Molyneux and Locke, while I believe they get the general idea right, I believe they get the actual answer wrong. The answer to Molyneux's problem should be "yes" --- the newly sighted can correctly associate the shapes. A sufficiently educated and intelligent person with congenital blindness would be able to correctly differentiate the shapes. Say, for instance, had Locke been born blind and still educated as rigorously. Of the many deductions that could be performed, the motion of the head with eyes fixed looking around the border of an object in space approximates the motion of the hand tracing the same object. Many other deductions are possible. All you need are reasonable assumptions about the acclimatization process, e.g., the patient can have a suitable amount of time to adjust to being sighted but cannot touch anything during the process. It is fascinating to think about the idea of disconnected senses, but as so commonly happens, fascination with an idea leads to sloppy thinking, especially among the educated. The reason why the empirical studies of the patients from India are wrong, despite being interpreted as giving a concurring answer, is that the blind have traditionally been given feeble educations, lacking in the type of rigorous thinking necessary to solve the problem. Historically it was challenging to teach abstract reasoning to the blind, and for this reason many were not taught. See Herzog's documentary "Handicapped Future" for tragic examples in relatively wealthy 1960s West Germany. http://en.wikipedia.org/wiki/Handicapped_Future http://en.wikipedia.org/wiki/Handicapped_Future The five patients in India who could not afford simple but life-altering surgery were sure to be poor in addition to being blind, and so surely must have received awful educations. Compounding this are their young ages. A sufficiently motivated, newly-sighted Locke would've gotten the answer correct.

xwowsersx 13y ago
I'm confused...Locke and Molyneux weren't saying the newly sighted person wouldn't be able to distinguish between the shapes, but that they wouldn't be able to synchronize that distinction with their touch sensations. In other words, they wouldn't be able to identify which was the one they identified, by touch, as spherical and which as square.
- ramchip 13y ago
  I do think that's what the poster is referring to: > the motion of the head with eyes fixed looking around the border of an object in space approximates the motion of the hand tracing the same object His argument is that this kind of abstract reasoning would be mostly developed by education, so people with very little education would not be able to associate the shapes they see with those they touched.

twelvechairs 13y ago

Surely this is not a hypothetical anymore or one with merely one test case - see http://en.wikipedia.org/wiki/Visual_prosthesis http://en.wikipedia.org/wiki/Visual_prosthesis for example. It seems obvious to me that it takes some time for people to get used to using a new sense - particularly for higher-order abilities. Differentiating 'round' from 'hard edged' is probably a fairly simplistic function which your brain should be able to quickly figure out, but I don't see how it can just be instant.

kenko 13y ago
I think this is exactly right. Tactile visual substitution systems provide a sensory modality that we may as well call sight, just not via the eyeballs, and it takes time for the blind to become capable with them. Why wouldn't it take time for them to become capable with a sensory modality that is causally associated with the eyeballs? And in fact, it does take time.

kenko 13y ago

http://plato.stanford.edu/entries/molyneux-problem/ http://plato.stanford.edu/entries/molyneux-problem/

Siecje 13y ago

I say yes. If you asked a blind person to draw a sphere they would draw a circle, if you asked them to draw a cube they would draw a square.