Slashdot Mirror


Blind Man Navigates Obstacle Maze Unaided

iammani writes "The NYTimes runs a story about a blind man (blind because of a damaged visual cortex) successfully navigating an obstacle maze, unaided. Scientists have shown for the first time that it is possible for people who are blinded because of damage to the visual (striate) cortex can navigate by 'blindsight,' through which they can detect things in their vicinity without being aware of seeing them."

191 comments

  1. Huh. by ScrewMaster · · Score: 0, Offtopic

    it is possible for people who are blinded because of damage to the visual (striate) cortex can navigate by "blindsight", through which they can detect things in their vicinity without being aware of seeing them."

    Yeah okay ... that's kind of creepy.

    --
    The higher the technology, the sharper that two-edged sword.
  2. his eyes are fine by timmarhy · · Score: 4, Informative

    his brain is still able to make use of the input comming from the eyes which are undamaged. interesting.

    --
    If you mod me down, I will become more powerful than you can imagine....
    1. Re:his eyes are fine by morgan_greywolf · · Score: 0

      No, he's not. Without a working visual cortex, nothing from the eyes enters the brain. At all. Most likely, he is using sound or air pressure. Blind people can often maneuver by hearing things like subtle changes in sound of footprints, etc., echoing off of or being aborbed by walls, etc. There are also subtle changes in air pressure as you approach obstacles, and that can often be 'felt' by blind people. The blind usually develop their other senses to a greater extent than sighted people as a means of compensating for the fact that they can't see. It just happens naturally.

    2. Re:his eyes are fine by timmarhy · · Score: 1

      RTFA and you'll see your wrong (too much to ask?). it's a form of vision he is using.

      --
      If you mod me down, I will become more powerful than you can imagine....
    3. Re:his eyes are fine by morgan_greywolf · · Score: 0

      I did RTFA. Again, as I said in an above post, I think the article is BS and the guy didn't see anything at all.

    4. Re:his eyes are fine by morgan_greywolf · · Score: 0, Redundant

      I did RTFA. And I think the article is a load of BS. The visual areas of the brain will light up because the brain doesn't know the difference between what you see with your eyes and what you see with your imagination and memories. IMHO, sight doesn't happen as much in the eyes as it does in the brain.

    5. Re:his eyes are fine by Anonymous Coward · · Score: 0

      You need to RTFA. Not all sensory data collected by the eye is processed by the visual cortex.

    6. Re:his eyes are fine by philspear · · Score: 5, Insightful

      Without a working visual cortex, nothing from the eyes enters the brain. At all.

      It would be really nice if hypothesis and biology worked like that, where biology followed our hypotheses, but it doesn't. It would be interesting to see an fMRI, or see if he could navigate the maze with earplugs or some way of throwing off air pressure. Assuming it can't possibly be his eyes connecting to some other part of the brain simply because textbooks say the eyes connect only to the visual cortex is not a safe conclusion.

    7. Re:his eyes are fine by ceoyoyo · · Score: 5, Informative

      "Without a working visual cortex, nothing from the eyes enters the brain. At all."

      Whoopsie. Apparently you didn't know about the body of work showing that there are connections between the retina and subcortical areas as well as the striate cortex. Of course, if you'd read the article, you would have noticed they mentioned that.

      Yes, I read your other comments, including the one where you claim to have read the article. To summarize: you don't think it's possible... because .

    8. Re:his eyes are fine by ceoyoyo · · Score: 1

      Read the article. Carefully. There's good evidence from other mammals that subcortical structures are activated in response to particular visual stimuli, independently of the cortex.

    9. Re:his eyes are fine by Anonymous Coward · · Score: 5, Informative

      Maybe the problem is that TFA tried to make the science more approachable to people, but you obviously don't understand a single thing about blindsight. This is nothing new at all. In layman's terms, the participant still experiences visual sensation but not visual perception -- they can still see, but they are unaware of it. What is significant in this case is the extent of the damage to the visual cortex. The sensory compensation of congenitally blind people is incredible, but this is an entirely different phenomenon.

      Sight doesn't "occur" in the eyes, but there are a number of subcortical structures the information passes through before it gets to the visual cortex. Which, oddly enough, is exactly what they say in TFA, which you claim to have read. They specifically say that the "visual areas of the brain" did NOT "light up", so I have no clue what you're babbling about.

      The entire point of the article is that the extent of subcortical visual processing (which we are unconscious of) is greater than most people realise. So feel free to read it again and appreciate what is actually a well-established neurological phenomenon.

    10. Re:his eyes are fine by sveard · · Score: 4, Informative

      http://www.amazon.com/Physiology-Behavior-MyPsychKit-Neil-Carlson/dp/0205593895/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1230187013&sr=8-1
      Chapter 1 has a short item on blindsight and it's relation to consciousness. You should really read chapter 1 of this book.

      IMHO, sight doesn't happen as much in the eyes as it does in the brain.

      Well, that's how the brain does its thing. Your eyes, ears, nose, skin, are instruments that extend from the brain. Data that flows from your senses to your brain lacks meaning until the brain processes it.

      A few posts earlier you say:
      ( http://science.slashdot.org/comments.pl?sid=1072951&cid=26228425 )

      Without a working visual cortex, nothing from the eyes enters the brain. At all.

      Blindsight does not imply that the visual cortex does not "work". Have a look at http://en.wikipedia.org/wiki/Primary_visual_cortex

      Data still flows from the eyes over the optical chiasm to the primary visual cortex (the cortex around the calcarine fissure in the occipital lobe). From there, there are multiple "streams" of visual data. One of those streams is the one that "enters" consciousness.

      It is the absolute certainty with which you refute the previous, and the postulation of the following near-superhuman senses that make you appear rather uninformed and quite arrogant.

      Most likely, he is using sound or air pressure. Blind people can often maneuver by hearing things like subtle changes in sound of footprints, etc., echoing off of or being aborbed by walls, etc. There are also subtle changes in air pressure as you approach obstacles, and that can often be 'felt' by blind people.

      Take a biological psychology course or your own medicine (your signature)

      http://www.scholarpedia.org/article/Blindsight
      http://en.wikipedia.org/wiki/Blindsight

    11. Re:his eyes are fine by Tekoneiric · · Score: 4, Informative

      Most likely those subcortical connections are there as a link to the reflex system. High level visual processing would likely take too much time to process for reflex action. Damage to the subcortical links but not to the visual cortex would likely make for someone that's slower to react to visual stimulus and very clumsy.

      --
      *It's not what you can do for the Dark Side but what the Dark Side can do for you!*
    12. Re:his eyes are fine by iocat · · Score: 3, Informative
      Actually, if you look at the video found here , you'll see that your theory of human echo-location is totally inadaquate to describe what he is doing -- he avoids the walls, but also an overhead projector on the floor and some really small items.

      If you RTFA (I know, a big assumption -- Google can take you to the no-registration-required SciAm version), they say that scientists suspect there are other pathways where the info is getting into his brain, even though his visual cortex is totally destroyed on both hemispheres. This is the first blindsight demo with NO visual cortex, and thus seems to suggest strong that there are some alternate pathways going on. He can also react to facial expressions.

      --

      Dude, I think I can see my house from here.

    13. Re:his eyes are fine by MillionthMonkey · · Score: 2, Informative

      "No, he's not. Without a working visual cortex, nothing from the eyes enters the brain. At all. Most likely, he is using sound or air pressure."

      The signal from the optic nerve doesn't go exclusively to the primary area of the visual cortex- it forks at the lateral geniculate nucleus before it gets there and some also goes to subcortical targets which provide functions like the flinching reflex. These are older pathways and modern vision evolved by eavesdropping on the signal.

    14. Re:his eyes are fine by Anonymous Coward · · Score: 0

      Without a working visual cortex, nothing from the eyes enters the brain.

      That's completely incorrect! Without a visual cortex, nothing enters the visual cortex!

      Signals which start in the retina travel through the optic nerves. The left and right optic nerves merge at the optic chiasm. After the chiasm the signals are split to left and right "side of the world".

      Some of these signals do not "crossover" L-R at the chiasm. They go directly to the Edinger Westphal nucleus in the brainstem, which is responsible for the pupillary constriction reflex when you see a bright light. This is why people who are cortically blind (the occipital lobe of the brain is damaged) still have light reflexes. For the parent: THIS HAPPENS IN THE BRAIN (i.e. brainstem).

      The most of the other signals will synapse on the lateral geniculate nucleus. This is in the thalamus. (Which for the parent this is ALREADY IN THE BRAIN!) From then the signals go to the visual cortex which enables us to the the pretty pictures in our mind.

      But even with visual signals only getting to the parts of the brain before the visual cortex, it seems someone can navigate well through obstacles - despite not "seeing" them.

      My point is, that the parent seems to misunderstand basic concepts, and should be modded down. Thanks!

    15. Re:his eyes are fine by Anonymous Coward · · Score: 0

      For anyone interested, this page has some quite simple (for a slashdotter :-P) diagrams that explain what I meant about "before the visual cortex".

      Central Visual Pathways

      Look at the second diagram. It has numbers from 1 to 6. This blind man probably has damage beyond point 6 - so he can't "see". But you can see neurons terminating in the LGN.

      There's another diagram under The Pupillary Light Reflex which shows a simple pathway that would also be unaffected in this man.

    16. Re:his eyes are fine by Anonymous Coward · · Score: 0

      I would suggest you read this book for more interesting case studies about the brain and down-to-earth descriptions.

      Phantoms in the Brain.

    17. Re:his eyes are fine by TapeCutter · · Score: 1

      "Without a working visual cortex, nothing from the eyes enters the brain."

      Technically the eyes are part of the brain. The visual cortex is brain jelly (mammalian GPU, one per eye, crosswired), perhaps you were thinking of the optic nerve. Nobody is claiming this is a "sixth sense", it's another part of the patients brain doing primative visual processing. Very similar to how some stroke patients have to learn to speak all over again.

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    18. Re:his eyes are fine by Anonymous Coward · · Score: 0

      Check YOUR spelling, and you'll see YOU'RE wrong.

    19. Re:his eyes are fine by Arancaytar · · Score: 1

      It would be interesting to see an fMRI, or see if he could navigate the maze with earplugs or some way of throwing off air pressure.

      It's quite tricky to eliminate all possible ways someone can navigate a maze, so it may be better just to turn it dark.

      You can't easily determine if he can still use his eyes, but working or not, they can only sense visible light. If he can navigate the maze without visible light, he's not using his eyes.

    20. Re:his eyes are fine by Anonymous Coward · · Score: 0

      Then why didn't he notice anything? Why wasn't he even aware of the obstacles?

    21. Re:his eyes are fine by Predius · · Score: 1

      Or, you could read the article, which points out that the retina sends signals to both the visual cortex AND some sub cortical areas. While his visual cortex was inert, the sub cortical areas were not, and based on this research they've determined that they can function independent of the visual cortex, and it appears they also perform some specialized visual functions such as facial expression recognition. This has been demonstrated in other animals, this was the first time it was confirmed in humans.

    22. Re:his eyes are fine by mpeskett · · Score: 1

      Hence why our startle reflex is quicker than our normal responses.

      I've seen a thing in the vein of those "reaction test" games, where you click as soon as a dot appears on the screen. But the 5th dot in the set is much bigger than the others, so it triggers your startle response. Cut my reaction time almost in half.

      Makes sense really - if something jumps out at you, you don't want to be waiting for the conscious mind to come up with a solution when a reflex response could already be happening.

    23. Re:his eyes are fine by philspear · · Score: 1

      That is indeed a better idea. I'd like to think I would have come up with it myself eventually.

    24. Re:his eyes are fine by Iguanadon · · Score: 1

      One of the classes I took this semester made us read books on modern neuroscience. I remember reading cases of people who are blind due to a brain injury, but have working reflexs in the "blind" eye. For example, if someone were to pretend to punch them in a blind area, they would automatically reach out there arm and block it perfectly, without "seeing" a thing.

      Vision in the brain is extremely complex, I don't remember the actual number, but there is something like 19 vision sections of the brain, each one has its own role. I believe vision as we know it only takes up a few of those sections.

      To make it more complicated, apparently there are two vision pathways, one new, one old. (By new and old I'm referring to the relative time they developed in the human species, the "new" system has probably been in us for thousands of years) The new one allows us to do more advance processing on images, while the old is used for more reflexes, hence the example above where a blind person can see.

      If anyone is interested in reading about modern neuroscience, I'd recommend V.S. Ramachandran's book, Phantoms in the Brain

    25. Re:his eyes are fine by dogmatixpsych · · Score: 1

      "Without a working visual cortex, nothing from the eyes enters the brain. At all. Most likely, he is using sound or air pressure."

      I'm sorry but that's completely incorrect. Light enters the eyes, hits the retina, is converted to an electrochemical signal, sent out the optic nerve, passes the optic chiasm, then heads back to the lateral geniculate nucleus of the thalamus. Most of the "signal" goes back to V1 in the occipital lobe but some signal also goes to the hypothalamus, superior colliculus (on the brainstem), and the pretectal nucleus in the brainstem, although that last pathway is mainly for pupillary constriction.

      This man likely had much of V1 damaged but not all of it. It would be enough to ruin his conscious experience of vision without destroying all of the neurons sending information dorsally to the parietal lobes.

      Blindsight is a well-known condition and is fairly common in such cases of cortical blindness. Scientists have known about it for many years. This research isn't new, it's just more confirmation of what we already know. So yes, this man is still having a lot of information enter the brain; much of it just can't be synthesized into usable form by his primary visual cortex. This has nothing to do with incorporating other senses, although those certainly could affect his ability to walk through a real maze.

    26. Re:his eyes are fine by rev_deaconballs · · Score: 1

      This actually makes sense. The first stage of navigation is Head Direction cells. These cells are found in a few regions including the thalamus (note it is not the LGN) and they receive indirect projections from the retina. The latest hypothesis is that the retrosplenial cortex is the entry way for vision in navigation. The retrosplenaial cortex receives direct input from the visual cortex and indirectly from the retina. This article suggest that the system is functional (most likely not as accurate) without visual cortex.

    27. Re:his eyes are fine by Arancaytar · · Score: 1

      Thanks! =P

    28. Re:his eyes are fine by Anonymous Coward · · Score: 0

      Yes, I read your other comments, including the one where you claim to have read the article. To summarize: you don't think it's possible... because .

      He didn't read the article, because HE'S BLIND you insensitive clod!

    29. Re:his eyes are fine by Anonymous Coward · · Score: 0

      Learn the difference between "your" and "you're" (too much too ask?).

    30. Re:his eyes are fine by Anonymous Coward · · Score: 0

      Yeah, the story is just bollocks.

      For example, on the BBC version the guy is quoted as saying that he was unaware that he'd avoided anything and just thought he'd walked straight down the corridor.

      That quote is the biggest clue that it's bollocks.

      Assuming there really were some "scientists" fooled by this trick and not just a journalist or 3, then it won't be the first time they have been, but they will soon be red faced.

    31. Re:his eyes are fine by Reservoir+Penguin · · Score: 1

      +1

      --
      US-UK-Israel: The real Axis of Evil
  3. Ben Underwood by futuresheep · · Score: 0, Redundant
    Navigating by sound.

    http://www.benunderwood.com/

    http://www.cbsnews.com/stories/2006/09/06/eveningnews/main1977730.shtml

    Ben had cancer in both eyes. But he discovered a way to beat his blindness. When he was about 6, he started "clicking," and quickly realized that the sound he made with his tongue bounced off things around him, giving him an idea what was there.

    1. Re:Ben Underwood by Gabrill · · Score: 4, Informative

      TFA specifically states that they ruled out echolocation.

      --
      Always going forward, 'cause we can't find reverse.
    2. Re:Ben Underwood by quantaman · · Score: 1

      TFA specifically states that they ruled out echolocation.

      Well they said they found no evidence that he was, I'd still like if they elaborated that they gave him earplugs or something, even footsteps could give him enough audible info to navigate.

      Ideally I'd like some mention of a control using a blindfold or something. From the sounds of it he wasn't truly blind, the eyes worked fine but signals either weren't getting to the brain, or weren't getting processed by the visual cortex. They seem to be suggesting the visual info is still somehow being processed to aid navigation.

      --
      I stole this Sig
    3. Re:Ben Underwood by Anonymous Coward · · Score: 1, Informative

      From the sounds of it he wasn't truly blind, the eyes worked fine but signals either weren't getting to the brain, or weren't getting processed by the visual cortex. They seem to be suggesting the visual info is still somehow being processed to aid navigation.

      .

      Congratulations, you found the point of the article. Many have failed to do so.

    4. Re:Ben Underwood by GarrettK18 · · Score: 1

      Ben Underwood , while a very inventive individual and cause for many "feel-good" stories in the media is, imo, a pussy. I'm going to laugh my ass off when he goes to an unfamiliar town (with no cane, mind you) and gets very disoriented. I spent almost a year with these guys, and they taught me a thing or two about echo-location and traveling.

    5. Re:Ben Underwood by GarrettK18 · · Score: 1

      Okay, that's what I get for not using preview! The correct site is here

  4. You know what they say by memristance · · Score: 5, Funny

    Blindsight is 20/20.

  5. Failed attempts by Anonymous Coward · · Score: 0

    If this is the first time they've successfully shown it...Think about how all the times they tried and failed.

  6. Its not that hard by Iamthecheese · · Score: 4, Interesting

    After some practice I could do it myself. So can you. Start with a hallway with hard walls and walk down it blindfolded using your ears. It may help if you make a high-pitched sound. (at least high-pitched sounds are easier for me) I can only avoid large objects that don't aborb sound myself, but I bet I could get better.

    --
    If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
    1. Re:Its not that hard by morgan_greywolf · · Score: 3, Insightful

      I don't doubt it all. Lots of people can. The brain automatically enlists your other senses when one of them isn't working. That's why I think the article is a just a load of BS. I don't think the man saw anything. I think his brain was just able to use his other senses to accomplish the same goal.

    2. Re:Its not that hard by BradMajors · · Score: 5, Interesting

      There is a video of a blind person on youtube who seems to be able to navigate just like a regular person through the use of echoes. He carries and uses a clicker to make sounds.

      There is a group which teaches the blind to locate objects through echoes.

    3. Re:Its not that hard by memristance · · Score: 5, Insightful

      There's only one way to be certain: repeat the experiment.

      I would suggest having the blind man and an average-sighted man separately walk down a very well-lit corridor with randomly positioned (i.e., changing every iteration) obstactles 10 times, recording the amount of time each takes and the number of collisions. Reduce the amount of lighting by some increment and repeat the experiment. Continue reducing lighting until total darkness is achieved.

      If the blind man is truly navigating by blindsight, both his course times and collision rates should roughly scale positively with those of the sighted man and inversely to the light levels. But then, that would be using the scientific method like the international team of neuroscientists in TFA (whom you are accusing of incompetence) did, so of course you wouldn't believe it...

    4. Re:Its not that hard by calmofthestorm · · Score: 4, Funny

      But blindsight is such a kickass name.

      --
      93rd rule of Slashdot: No matter how obvious my sarcasm is, my comment will be taken seriously by someone.
    5. Re:Its not that hard by BikeHelmet · · Score: 3, Interesting

      Brain Plasticity - his subconscious is figuring out how to make use of some form of input, to give him a sense that something is there.

      I bet if he did it over and over, he'd get better at it. It'd strengthen the connections.

    6. Re:Its not that hard by GarrettK18 · · Score: 5, Informative
      Full disclosure: I was born 3.5 months premature, and my retinas detached at 4 months.

      I call it being able to hear the "sound shadows" of objects, because that's really what they are - an object blocks sound, and that blockage is projected to the ear. With a good cane, I can navigate around tables, columns, and even position myself relative to peoples' voices to keep myself from running into them. It's quite amazing what you can tell with a good hallway, and a constant sound source (soda/vending machines are good). For example, an open, echoy space usually means a stairwell.

      Also, randomness ... the first time I went to post, my screen reader was very sluggish and crashed. I guess Slashdot hates blind Linux users.

    7. Re:Its not that hard by TheModelEskimo · · Score: 1

      Don't worry, Slashdot is the tab that always crashes Firefox for me now, and I'm not blind. I think Slashdot just hates everybody. Before us I guess it was IE users. ;-)

    8. Re:Its not that hard by lgw · · Score: 4, Interesting

      That's very cool. It's also proof of how amazing the brain is - the part that makes a 3D model of your surroundings will adapt to any sort of useful input. With just sonic shadows you're working with very limited data, but even so: the navy has spent a ton trying to develop good passive sonar, and it sounds like you're better at it than the technology. Now if someone could just invent a sonic lens, it would close the gap. The only reason light gives better 3D positional information is the lens (though it would also be helpful to hear sub-millimeter wavelengths, as 20 kHz doesn't give much precision).

      --
      Socialism: a lie told by totalitarians and believed by fools.
    9. Re:Its not that hard by BikeHelmet · · Score: 1

      Brain Plasticity - his subconscious is figuring out how to make use of some form of input, to give him a sense that something is there.

      Alright, then. How about you suggest an experiment that would isolate the correct variable.

      Stop coming up with excuses. If you can't suggest a better experiment, don't complain.

      No thanks. Someone would just prove it wrong in 5 years, anyway. :P

      I wasn't complaining. Seems that all these theories have common roots.

    10. Re:Its not that hard by weicco · · Score: 5, Funny

      There is a group which teaches the blind to locate objects through echoes.

      Bene Gesserit?

      Sorry, I'm reading the book Paul of Dune which I just got as a Christmas present. Couldn't help myself... :)

      --
      You don't know what you don't know.
    11. Re:Its not that hard by Laser+Dan · · Score: 5, Insightful

      Isn't it obvious or am I missing something here??
      Blindfold the blind man and repeat the experiment with/without the blindfold. That will tell if vision is being used in any way.

    12. Re:Its not that hard by Laser+Dan · · Score: 1

      Would a blind person be an awesome sonar operator then?
      Just plug 'em into the array with no processing of the signal...

    13. Re:Its not that hard by Paaskonijn · · Score: 5, Interesting

      Do you mean this kid?
      http://uk.youtube.com/watch?v=qLziFMF4DHA
      (That's part 1 of the documentary. Links to the other parts are in the info box.)

      Incredible stuff, he rides a bike and everything!

      What isn't explained though is how he's playing video games?

    14. Re:Its not that hard by Anonymous Coward · · Score: 0

      Now if someone could just invent a sonic lens,

      Yeah, if only...

    15. Re:Its not that hard by jonbryce · · Score: 1

      We are much better at OCR and object recognition than any computer is, so that isn't particularly surprising.

    16. Re:Its not that hard by Anonymous Coward · · Score: 5, Funny

      I suggest a double blind test.

    17. Re:Its not that hard by TempeTerra · · Score: 1, Informative

      The article sure reads like BS, but that's popular science for you. I read about this kind of thing back in first year psychology (never did second year, I don't claim to be an expert). The brain is, frankly, a complete fucking mess from a design perpsective. It's entirely possible to knock out random parts of abilities that would be unitary if the brain was well designed, particularly through strokes or other injuries that damage small parts of the brain exclusively. Speech centres are classic; people lose their nouns, or the ability to speak entirely but can still swear reflexively because the reflex is in a different part of the brain.

      I read about this kind of blindsight too, I'm not sure how this case is exceptional except that it's recent news and it's an uncommon condition. It's not magical (except when pop sci journalists need a story), it's just that the brain doesn't store all its functionality in logical places. I forget what the explanation I read was, but most likely the hardware for visually identifying objects is in a different place from the hardware for avoiding objects (regardless of what they are). IIRC, there are edge detecting cells in the eye, so it's plausible that something like a wire frame model gets sent down the optic nerve even before the visual areas get to work on it. There's quite a lot of visual cortex, and I suspect the journalist was glossing over some of the details. As I said, it sounds like BS except for the background I already know.

      Fun further experiments: throw balls of rolled up paper at his head and see if he can dodge them; get him to throw things at a target! Both are plausible if he has object-sensation but not object-identification.

      --
      .evom ton seod gis eht
    18. Re:Its not that hard by sjames · · Score: 2, Informative

      While that is true, that's not what's happening here. In the case from TFA, the man is not conscious of any visual sensory input, but IS able to subconsciously make use of visual information. Also from TFA, he has the same subconscious responses to being shown pictures of people's faces displaying various emotions and other responses that cannot be due to echolocation.

      In another experiment (not part of TFA) a number of subjects with cortical blindness were able to accurately state which direction a dot of light was moving across a screen at a rate far above chance. It is suggested that they can improve upon their results with practice.

    19. Re:Its not that hard by harry666t · · Score: 1

      > What isn't explained though is how he's playing video games?

      Reminds me of Wu Zi Mu of GTA:SA...

    20. Re:Its not that hard by Rorschach1 · · Score: 2, Interesting

      Sighted people can learn this, too. I worked in an office where I had my back to a doorway, and through that door was a room full of servers. No one was ever able to sneak up on me because I could hear their sound shadow as they walked by the servers. It took me a while to figure out how I was aware of them, because it wasn't really a conscious thing at first.

    21. Re:Its not that hard by residue · · Score: 2, Insightful

      What about the faces?

      The sound hypothesis does nothing to explain how the man reacts to various faces presented to him.

    22. Re:Its not that hard by Anonymous Coward · · Score: 0

      Do you realize (real eyes) just how profound your statement is? metaphorically speaking

    23. Re:Its not that hard by asCii88 · · Score: 2, Informative

      RTFA. Of course he would hit the obejcts. The article states that the person needs working eyes and that the vision he gets is unconcious.

    24. Re:Its not that hard by hemorex · · Score: 1

      Seems to me that what this indicates is that the information passed into the eyes is slapped into several different parts of the brain, and used in different ways. So, instead of a single image that is altogether processed by our conscious mind, we have different parts of the brain using this information to determine objects to avoid, reactions of other things around us, and so on. And why should this be a surprise? Consider that basic obstacle avoidance is a feature of extremely simple organisms based on very limited input; it seems plausible that this mechanism would remain separate, and a new mechanism would pop up to handle 'details' that did not require an immediate reaction. Oh, yes, I Am Not A Neurologist, sorry!

    25. Re:Its not that hard by Anonymous Coward · · Score: 0

      it would also be helpful to hear sub-millimeter wavelengths, as 20 kHz doesn't give much precision

      The problem is that at super-high frequencies, air damps out the signal quickly. Even if you used an augmented hearing device to let you hear super-high frequencies it would be of limited use because you would have to be really close to the objects.

    26. Re:Its not that hard by pacificleo · · Score: 1, Funny
      "The brain is, frankly, a complete fucking mess from a design perpsective."

      Thats Intelligent design for you.
      jokes apart this "Blind sight " thing might have some grain of truth. its more likely to happen to people who are Not blind by birth but who loose their sight. this will be an interesting variation in the experiment . this is somewhat similar to Phantom Arm phenomena . there is a neuro anatomical explanation for this.

      --
      somethings are best left unsaid , I am one of those things
    27. Re:Its not that hard by pacificleo · · Score: 0

      here is a video of Evelyn Glennie she is a deaf percussionist who claim she "Listen" music through here body . you got to see her preform to believe it .

      --
      somethings are best left unsaid , I am one of those things
    28. Re:Its not that hard by cratermoon · · Score: 3, Insightful

      Why is redundancy a mess? A unitary design would be prone to complete failure at even minor damage, so would be selected against.

    29. Re:Its not that hard by chrismendez · · Score: 2, Insightful

      I would think the blindfold might have a psychological effect. I like the idea with lights much better, so he wouldn't know which is which.

    30. Re:Its not that hard by sjames · · Score: 1

      Not to mention that the cerebellum needs visual feedback and does it's job beneath conscious level. I wonder how it would go if blindsighted people try to catch (for example) a tossed beanbag.

    31. Re:Its not that hard by iluvcapra · · Score: 1

      It may help if you make a high-pitched sound. (at least high-pitched sounds are easier for me)

      The higher the pitch, the closer the wavelength, and at the distances we're talking about (centimeters to meters) you're auditory system will be doing localization with phase differences and wavefronts instead of actual "echo," since the time delays on echo are pretty hard to pick up on so close to the listener (believe it or not, but your ears-brain loop is extremely sensitive to phase differences between the two ears).

      By this method, you cannot detect objects or features smaller than the wavelength of the sound, so you'll need a wavelength at least as short as you are wide, in order to avoid hitting something that would stop you, and this comes out to about 1 kHz (34 cm). 3 kHz is ideal, since we have a natural sensitivity there (the speech band that allows us to hear consonants), and that's about 11cm (about the size of your head, conicidentally). Above that, you get better imaging, but your ears get less sensitive, so you need the tone to be louder.

      --
      Don't blame me, I voted for Baltar.
    32. Re:Its not that hard by iluvcapra · · Score: 1

      Why yes, my head was shrunk by a tribe on the Solomon Islands, you insensitive clod!

      --
      Don't blame me, I voted for Baltar.
    33. Re:Its not that hard by Anonymous Coward · · Score: 0

      blindsight is always 20/20...

    34. Re:Its not that hard by ozphx · · Score: 1

      A blind man can't read non-existant writing at 20ft that a sighted man couldn't read at 20ft?

      --
      3laws: No freebies, no backsies, GTFO.
    35. Re:Its not that hard by Sir+Holo · · Score: 1

      Agreed! Although I am fully sighted, from childhood I would practice walking down dark hallways with eyes closed. The "sound shadows" you describe are only a part of it - an analogy that the sighted can grasp.

      Local changes in reflectance and absorbance of sound as you navigate a 3-D space are also richly informative as to the shapes and types of surfaces around you, in addition to their locations. It is particularly powerful in a space with which you are familiar, like your home.

    36. Re:Its not that hard by metaforest · · Score: 1

      When I was studying Aikido years ago there was an exercise used to teach/explore so-called 'Action-at-a-distance' I learned that much of the result is becoming body-sensitized to your environment without using visual stimulus. The human brain does seem to adapt to this very quickly if some basic meditation to clear the mind is done first. I noted: â Heightened sensitivity to near by heat sources (esp. people) from any direction. â Using ambient sound to map the position, size and character of near by objects and interior spaces using auditory and temperature/air current cues â Apparent awareness of other people's intent... (not really mapped on the remaining four senses) Consequently, I find it relatively easy to walk through unfamiliar areas in near total darkness. I can demonstrably catch things thrown in my direction without having see the object thrown: even in cases where someone was trying to surprise me. And the most useful.... I cannot be snuck up on or followed without being aware of it... In fact the only person who has successfully snuck up behind me in many years was a fellow Aikido student, who stated that he had to clear his mind of intent before attempting it.... You see we had been playing this game for some time.... YMMV

    37. Re:Its not that hard by lgw · · Score: 1

      Perhaps a sonic lens a bit more portable - lugging a sperm whale around with you gets tiring after a while.

      --
      Socialism: a lie told by totalitarians and believed by fools.
    38. Re:Its not that hard by Reziac · · Score: 1

      And to eliminate the "sonar" factor -- earplugs.

      From TFA:
      ========
      They include place cells, which fire when an animal passes a certain landmark, and head-direction cells, which track which way the face is pointing. But the new study also found strong evidence of what the scientists, from the Norwegian University of Science and Technology in Trondheim, called 'border cells,' which fire when an animal is close to a wall or boundary of some kind.
      =====
      I suspect this is the same phenomenon as those 'border cells': When I was a kid, I could "feel" other people *as if they were touching me* as soon as they got within about 4 inches of my body, even if I couldn't see them. This was very consistent.

      --
      ~REZ~ #43301. Who'd fake being me anyway?
    39. Re:Its not that hard by rubycodez · · Score: 1

      that would be a good name for the decision making process used by a president who never used foresight nor hindsight

    40. Re:Its not that hard by mokumegane · · Score: 1

      Actually, there are scientists that are repeating experiments with both blind and normal people. They are saying we are using a sonar-like process like bats do. They blindfold everyone and do tests with solid areas, soft areas, tap shoes, no tap shoes, etc. Solid surfaces with tap shoes worked the best over everyone. I think I saw this on one of the HD Discovery or Science channels on TV.

    41. Re:Its not that hard by kalirion · · Score: 1

      In The Man Who Mistook His Wife For A Hat there was a woman (IIRC) who had brain damage and could not conciously perceive objects in one part of the visual field, but could easily interact with them. As in when asked "Is there a ball on the table" she would say "No.", but when asked to pick up the ball on the table, she'd reach directly for it and pick it up without feeling around. Or something like that, it's been a while since I read the book in high school.

    42. Re:Its not that hard by againjj · · Score: 1

      TFA specifically mentions that echolocation was not used.

  7. Dolcet berries... by Anonymous Coward · · Score: 0

    Wil McCarthy's "Queendom of Sol" science fiction series released a few years back had Blindsight used as the basis of an advanced martial arts discipline in the final volume, "To Crush The Moon". (Read them in order or you'll be very confused). He swore he wasn't just making the phenomenon up at the time. So... guess he wasn't.

  8. this explains Zatoichi by Greg151 · · Score: 1

    http://en.wikipedia.org/wiki/Zatoichi My favorite Japanese movies. Gotta love Shintaro Katsu's portrayal of a blind man.

  9. His name was Squeaky by infonography · · Score: 1, Funny

    Some say he's a goth but others say he's just batty.

    --
    Sorry about the writing. Robot fingers, you know? Cliff Steele in DOOM PATROL #23
  10. Blind awareness? by IrritableBeing · · Score: 0, Interesting

    So how can someone be aware of something in the vicinity without seeing or touching it? Are they saying that this guy has developed some type of sixth sense? Or is this an ability that everyone has.. like when you're sleeping and someone gets real close to you, you wake up as if your subconscious detected them.

    If this is true, then we should try to tap into this ability more often. You know, train ourselves to be able to use it on command or 24/7. I can think of a few instances where this could come in handy.

    1. Re:Blind awareness? by Anonymous Coward · · Score: 0

      If you had RTFSummary, you'd know that there is nothing wrong with his eyes, his blindness is entirely due to brain damage and that his ability to navigate was not due to other senses, but information from the eye being received in subcortical areas and relayed without conscious knowledge.

    2. Re:Blind awareness? by IrritableBeing · · Score: 0

      I didn't RTFA..but after reading it, I prefer my imagination.

  11. Sighted Persons Unable to Navigate TFA by Oswald · · Score: 5, Funny

    Doctors remain baffled at the inability the majority of Slashtards to read and comprehend a simple article summarizing a medical experiment, despite apparently functioning visual systems. "They just wouldn't quit insisting that the subject of the experiment used echolocation to navigate the obstacles in the hallway, no matter how clearly and explicitly the article explained that the possibility had been ruled out," say baffled researchers. "We don't think their brains are wired correctly."

    1. Re:Sighted Persons Unable to Navigate TFA by sagematt · · Score: 4, Funny

      I didn't bother to read the whole FA because I am blind, you insensitive clod!

    2. Re:Sighted Persons Unable to Navigate TFA by Anonymous Coward · · Score: 0

      Slashdotters have long been known for their ability to navigate replies on a topic without seeing TFA.

    3. Re:Sighted Persons Unable to Navigate TFA by Elsan · · Score: 1

      So... he's like Daredevil, right?

    4. Re:Sighted Persons Unable to Navigate TFA by jesdynf · · Score: 1

      Alright, you. I use this phrase vary sparingly -- but, I did indeed Laugh Out Loud. So there you go.

      --
      Yahoo! Pipes are awesome. How awesome? http://pipes.yahoo.com/jesdynf/slashdot
    5. Re:Sighted Persons Unable to Navigate TFA by Anonymous Coward · · Score: 0
      I've read the responses from the less-than-informed. I can only conclude that these people are either electrical engineers or, heaven forbid, programmers. Most EEs are quite arrogant and think they know a lot when it comes to biology, but I've met a few EEs who understand that biology has them beat in all areas. EE is good for making toys, though.

      But no one, NO ONE beats the arrogance of the software monkeys. I don't know if it's because they live in a virtual man-made universe of simple math, or that they are defective people to start with and are drawn to the simple-minded programming crap, but I've never heard so much "I the brain were properly designed" garbage as from programmers. Here are people who can't even recognize speech with multi-GHz parallel CPUs, but they are sure they know how to do better than biology. Fucking useless nerds.

    6. Re:Sighted Persons Unable to Navigate TFA by Waccoon · · Score: 1

      This should be more Insightful than Funny. I think you're theory is correct!

  12. Turn in your nerd badge by BitHive · · Score: 4, Interesting
    Whoever tagged this "badscience" should take an introductory neuroscience course sometime.

    For those whose curiosity hasn't entirely been replaced by fashionable knee-jerk skepticism, your optic nerve does not only terminate in what we think of as primary visual cortex, it sends projections to other areas as well, though these areas do not contribute to what most of us think of as "sight"

    1. Re:Turn in your nerd badge by Kingrames · · Score: 2, Insightful

      It should be no surprise that a blind man can navigate a maze. Blind men have successfully navigated mazes faster then others for quite a while.

      That's because their navigational algorithm is much simpler. put your hand on the right wall and follow it.

      You'd be surprised how much easier things can get when you eliminate useless data. This, however, seems to be a more noteworthy experiment in that it was more than just a regular old maze with two ends.

      Perhaps this will be the first step in discovering psionic potential? If so, sign me up for multiclassing.

      --
      If you can read this, I forgot to post anonymously.
  13. Uhno by ShakaUVM · · Score: 4, Informative

    This is hardly the first time blindsight has been demonstrated. I recall Ramachandran at UCSD doing experiments on it a while back.

    One of the more mind blowing things I read in 2008 was the discovery of a third type of visual receptor besides rods and cones. Essentially there's a third type of receptor that only detects sort of gross levels of light, and feeds directly into the system which regulates your circadian rhythm and is used for some other purposes. People that were completely blind were able to tell when light levels were fluctuated in a large way, like walking in front of a TV, and be totally puzzled how they knew that, since it didn't register as sight at all for them.

    The fact that these neuroscientists would call it the first evidence for blindsight means that either they really didn't read their papers very well, or it was a bad article summary on Slashdot.

    1. Re:Uhno by Belial6 · · Score: 1

      Or maybe they just heard the incredibly load buzzing that TVs emit when they are turned on.

      I jest about doubting you, but I'm serious about the TVs. Those things are loud!

    2. Re:Uhno by daniel_newby · · Score: 1

      One of the more mind blowing things I read in 2008 was the discovery of a third type of visual receptor besides rods and cones. Essentially there's a third type of receptor that only detects sort of gross levels of light, and feeds directly into the system which regulates your circadian rhythm and is used for some other purposes.

      Those are the photosensitive retinal ganglion cells. In addition to driving the circadian rhythm generators, they also control pupil size in response to light. IIRC, research in cats found that they do connect to the visual cortex, although how the signals are perceived is not yet known.

    3. Re:Uhno by ShakaUVM · · Score: 1

      Those are the photosensitive retinal ganglion cells. In addition to driving the circadian rhythm generators, they also control pupil size in response to light. IIRC, research in cats found that they do connect to the visual cortex, although how the signals are perceived is not yet known.

      Yeah, those. The really interesting thing is that people have been dissecting human eyes for many, many years without noticing them before.

      While they may connect to the visual cortex, there is no perception of light from them, so people who are born with no cones or rods are still without a sense of vision.

    4. Re:Uhno by Anonymous Coward · · Score: 0

      Precisely. In Ramachandran's book, Phantoms In the Brain, there is a specific anecdote about a woman who, due to stroke, had had her primary visual cortex destroyed. She was presented with a letter slot at a random angle, and an envelope was placed in her hand. After being told to put the envelope through the slot, and after balking at the notion because she was blind, she managed to successfully insert the envelope into slot 100% of the time.

    5. Re:Uhno by flewp · · Score: 1

      Yeah, those. The really interesting thing is that people have been dissecting human eyes for many, many years without noticing them before.

      Just out of curiosity, just how complex are eyes in the biological sense? I always hear it as a basis for intelligent design, as in "eyes are too complex to have been the result of evolution" or some other such line of reasoning (or lack thereof). Are the eyes themselves really that complex, much more so than other organs, especially the sensory one? Or is it that the corresponding brain areas and functions related to sight are really that much more "complex/advanced" (for lack of better words)? Or are the eyes and their related brain functions really not all that much more complex in the scheme of things?

      --
      WWJD.... for a Klondike bar?
  14. Since you apparently read TFA by NotQuiteReal · · Score: 1

    Did they also rule out long whiskers? Or perhaps other unsightly hair. A blind person might not have the best grooming habits.

    (Am I going to hell for posting this on Christmas eve?)

    --
    This issue is a bit more complicated than you think.
    1. Re:Since you apparently read TFA by multisync · · Score: 1

      Maybe he's got really long, Howard Hughes-like toe nails that he's subconsciously using to detect the boxes and tripods.

      (Happy Christmas!)

      --
      I don't care why you're posting AC
  15. Recursion... by gandhi_2 · · Score: 1

    ...FTW.

  16. Registration required by Mozk · · Score: 5, Informative

    From bugmenot.com:
    Username: arizonafrank
    Password: poochie

    --
    No existe.
  17. My daughter confirmed this story for me a year ago by LenE · · Score: 4, Interesting

    My daughter had a stroke before she was born, and as a result, she suffers from Cortical Visual Impairment (CVI), like the subject of this story. At nine months of age, she couldn't tell light from dark, which really screwed up our sleep cycles. Her eyes were fine, but her brain could not process the signals that they were sending to her.

    Eventually, she did regain some amount of vision, but her hearing is still her primary way of "seeing" things. Whenever we go into places that are pitch dark, my wife and I are walking into things left and right. My daughter, on the other hand, cruises right around like a bat. She hears walls and other obstructions, and corrects her course to avoid them. Her object avoidance skills greatly diminish when she can use her eyes to see, as her brain has to work much harder to decode what she sees with her eyes.

    -- Len

  18. Blindsight, Deafhearing and Alien Limbs by DynaSoar · · Score: 4, Informative

    There are two distinct causes of blindsight (and deafhearing and alien limb syndrome), damage to the primary sensory cortext but not the secondary or assosiation cortices, and damage to the association cortex, but not the sensory.

    The latter is easy to explain. The person can perceive, but can't incorporate the fact of it into their conscious experience. They can't "own" the perception. This is very often found in damage to the somatosensory cortex which leaves partial paralysis. Often the person can't perceive the limb attached to their body as 'theirs'. Sensations in the limb do not become perceptions for them. Similarly, vison and hearing can occur, and the brain can make use of the data, but the person can't perceive it because it's not coming from "them".

    The former is harder to explain. There seems to be a parallel visual (and auditory) system through which information can pass and the brain make use of, but which bypasses the association cortex. The person can't perceive normally, but if tested they react as if they can. They can, for instance, consistently "guess" the number of fingers shown them. There is a similar system for somatosensory. Perception of touch to, say, the hand, has highly detailed "maps" elsewhere on the body. For the hand it's on the cheek and on the back just below the shoulder. Just why this secondary pathway exists is a mystery. But it does, in most people.

    Around 20 years ago in Coevolution Quarterly there was an article about a 'school' in (IIRC) New Mexico that taught people to use their blindsight to navigate in the desert at night. The secondary visual pathway that persons with the second form of blindsight use, exists intact in everybody. It's not something you develop because of damage, it's something that's there in case you need it but below the level of consciousness so as not to interfere with normal perception. Occasionaly hunters, hiker/campers or survival technique practioners will hear of a person who can literally run through a pitch black forest without running into anything. These people have the ability to react to the subliminal perception from the secondary visual system in what occurs to them as instinctive reactions because they don't consciously perceive anything.

    --
    "I may be synthetic, but I'm not stupid." -- Bishop 341-B
    1. Re:Blindsight, Deafhearing and Alien Limbs by Plekto · · Score: 4, Interesting

      There's also other differences as well. Some women, for instance, have see a fourth set of colors, which gives them a much greater low-light ability (a couple for every thousand women, IIRC) as well as do great things in the visual arts. Other people have vision that extends a bit beyond the normal ranges as well. A good example if this is the typical "normal" body temperature. It was obtained by sampling a large number of people and averaging the result. Vision, hearing, and other senses are similar. So it's not surprising that the occasional blind person can actually tap into these if theirs happen to naturally be more developed than normal.

      By tapping into the secondary pathways like this, I can "see" about twice as well as most people in the dark(though it's not really "seeing" like reading a paper or like a cat does). And, as DynaSoar mentioned, I can literally run through areas at night and not hit things as long as there is even a tiny amount of light.(doesn't work in caves/absolute pith black - tried that - heh)

      Note - the skill can be learned, though some see better at night than others. I suspect their vision is shifted a bit more towards the infrared or their iris' are a bit larger. It took me about 2-3 years to develop it when I was growing up. My friends and I always spent a lot of time playing outside at night and some of us got pretty good at avoiding things in the dark. The hard part was learning to just trust your instincts. It's a odd feeling, though, as you only notice things a split second before you normally would hit them if you're moving faster than walking speed.

      I found that a trick to doing this - and you can try this as well - is to learn to defocus your eyes during the day. Animals do this to track movement. It's a common trick hunters also use to track and find game. If you can then also do this at night, it basically shuts off a lot of your brain's trying to strain itself in low light. Since the average person's brain normally focuses intently upon just a small area in front of them, expanding that to your entire field of vision makes a huge difference.(though as noted, you can't focus on specific objects at the same time) Often, even if you can't actually see details, your eyes will notice things like faint reflections, movements, and so on.

      My ex? She's nearly completely blind about 5 minutes after dusk. Opposite end of the scale as it were.

    2. Re:Blindsight, Deafhearing and Alien Limbs by 1+a+bee · · Score: 1

      mod parent up, that was a good read..

    3. Re:Blindsight, Deafhearing and Alien Limbs by DynaSoar · · Score: 1

      Plekto, are you reading my mind? I purposefully withheld mention of my own night vision. You supplied not only details of it, but of how I developed it. Your accounting tells the tale so exactly it's almost spooky. But given the mind that I have, it ends up as considering how much more likely I am to be able to find and test enough people in a similar task in order to determine why some have this and others do not.

      One point of contention, there are not "some women that see in 4 colors". There are some people called tetrachromats who have four color receptors. They do not see four colors, they see the same appx. 3.5 million colors. They just have better color acuity (they can tell the difference between two colors better).

      --
      "I may be synthetic, but I'm not stupid." -- Bishop 341-B
    4. Re:Blindsight, Deafhearing and Alien Limbs by sjames · · Score: 1

      Occasionaly hunters, hiker/campers or survival technique practioners will hear of a person who can literally run through a pitch black forest without running into anything.

      Actually, that is a combination of using other senses, stepping in a way that allows you to adapt to unanticipated terrain, and learning a different mode of vision that avoids tracking objects of interest with the fovea (which provides detailed color vision but is less sensitive to low light than the peripheral vision). I've done it many times.

    5. Re:Blindsight, Deafhearing and Alien Limbs by sjames · · Score: 1

      The same visual technique can also be used to spot dim satellites. Start out fully de-focused looking over the entire sky. Before long, you'll feel an 'urge' to look to a particular place. DO NOT do so. Instead, look near that point but not quite focused. Then you can see the rather dim light moving slowly against the background. It may appear to blink out occasionally if you let it get too close to your central vision (it is a constant brightness, the blinking is a visual artifact).

    6. Re:Blindsight, Deafhearing and Alien Limbs by residue · · Score: 1

      I agree with all this, except that any secondary pathways for vision, unconscious or otherwise, still obey laws of physics, and can't function in the dark!

      The ability to use the secondary pathways should go down proportionally to how the primary pathways deteriorate with decreasing light.

    7. Re:Blindsight, Deafhearing and Alien Limbs by DynaSoar · · Score: 1

      The same visual technique can also be used to spot dim satellites. Start out fully de-focused looking over the entire sky. Before long, you'll feel an 'urge' to look to a particular place. DO NOT do so. Instead, look near that point but not quite focused. Then you can see the rather dim light moving slowly against the background. It may appear to blink out occasionally if you let it get too close to your central vision (it is a constant brightness, the blinking is a visual artifact).

      It's also how those with very good or well corrected vision can see Mizar's visual double Alcor (the star in the center of the Big Dipper's handle). The separation is enough, but Alcor is much dimmer and difficult to perceive, especially with current levels of light pollution.

      It's not the same. I've been an amateur astronomer for over 4 decades and am very familiar with the technique. It's based on the fact that the more light sensitive rods are squeezed out of the central visual field by the color sensitive cones, making things only a few degrees off center appear brighter. The off-center technique still results in conscious perception. Blindsight/night vision does not. OTOH, that makes night vision suck for astronomy; it does no good to look if you don't know you're seeing it.

      Come to think on it now, it seems to me night vision requires movement, or a change in the visual field from not-there to there in the manner of a blink comparator. When I used night vision, if I wasn't moving I had to pan around to use it.

      --
      "I may be synthetic, but I'm not stupid." -- Bishop 341-B
    8. Re:Blindsight, Deafhearing and Alien Limbs by sjames · · Score: 1

      It's not the same. I've been an amateur astronomer for over 4 decades and am very familiar with the technique. It's based on the fact that the more light sensitive rods are squeezed out of the central visual field by the color sensitive cones, making things only a few degrees off center appear brighter. The off-center technique still results in conscious perception. Blindsight/night vision does not. OTOH, that makes night vision suck for astronomy; it does no good to look if you don't know you're seeing it.

      It isn't exactly the same, but the part of finding the satellite IS based on the alternative visual pathways. The rest is significant training of both conscious and unconscious pathways to prevent attempts to track to the center of vision.

      Beyond potential for rehab, the big reason neurophysiologists are interested in blindsight is that it affords the opportunity to map out which part of the visual systems does what for us. Very few people are even aware of it at all other than having visual perception. Sailors, astronomers, and some martial artists are amongst the few who may have a bit more feel for it due to training.

    9. Re:Blindsight, Deafhearing and Alien Limbs by Vegeta99 · · Score: 1

      It doesn't have to break the laws of physics! Your conscious vision is concentrated around the point you focus on. That is, you're throwing out some of the data about light surrounding that focus point. That doesn't mean it's not there!

    10. Re:Blindsight, Deafhearing and Alien Limbs by Reziac · · Score: 1

      [blink] I'm a little nearsighted (20/40 and 20/80) but I can see that double star without even thinking about it. With correction, it's perfectly evident.

      However, I'm one of those freaks with obscenely precise colour vision; I also see VERY well in the dark (and tend to see better by looking straight at something than by the "not quite at it" technique). I suspect the two abilities are related. -- Conversely my neighbour, while not per-se colourblind, has poor colour vision with some deficit in yellow, and poor distinction among reds; she also sees VERY poorly in the dark, even with full correction and no retinal issues. Again, I suspect the deficits are related.

      I do think some of us freaks have colour ranges that aren't kosher. Frex, when I had a woodstove, I could tell how hot the black metal top was by sight, even tho it stayed black; I suspect I was seeing a tish into infrared. On the other end of the visible spectrum, I see "black lights" as painfully bright.

      BTW apparently there is disagreement on whether Tetrachromacy is strictly a female thing; from Wikipedia: "Another study suggests that as many as 50% of women and 8% of men may have four photopigments. [cite: http://www.klab.caltech.edu/cns186/papers/Jameson01.pdf "It is also the case that an estimated
      8% of males presumed to be color "normal" likely
      represent a four-photopigment retinal phenotype
      heterozygous carriers."]

      --
      ~REZ~ #43301. Who'd fake being me anyway?
    11. Re:Blindsight, Deafhearing and Alien Limbs by residue · · Score: 1

      I'm referring to the "running through a pitch-black forest" and "navigating the desert at night" - in these cases the light really isn't there!

      If you can't see because there are too few photons reaching your retina, it doesn't matter which neural pathways you're using, you're blind!

  19. What's his midichlorian count? by Sryn · · Score: 2, Funny

    Obi-Wan Kenobi would be proud.

    1. Re:What's his midichlorian count? by NotAsGeekyAsYou · · Score: 1

      I knew something was missing from these comments, can't believe it took this long. Much appreciated.

  20. Re:It's Ch'i energy by Anonymous Coward · · Score: 0

    It's Ch'i energy

    His qi energy...IT'S OVER 9000!

  21. Bring 'em on! by Tablizer · · Score: 0, Offtopic

    Let the G. W. Bush jokes roll!

      -1 Trollcular

  22. Comedic irony by Anonymous Coward · · Score: 1, Funny

    RTFA and you'll see your wrong

    1. Re:Comedic irony by justthinkit · · Score: 1, Funny

      Re-read your six words and you will see your wrong.

      --
      I come here for the love
  23. See It Now by hyades1 · · Score: 4, Interesting

    If you ever want to see this in action, there's a very simple experiment you can do. Put a quarter inside a ring of five loons (Canadian $1 coins). Put another quarter inside a ring of five dimes. The quarter surrounded by dimes will look larger than the other one.

    Reach out and pick one up. Put it back. Pick the other one up. Put it back. You'll notice that even though your eye is telling you the two quarters of different sizes, your fingers will automatically spread out just the right amount to pick up either coin.

    The illusion works for your regular visual system. The unconscious one gets the answer right.

    --
    I've calculated my velocity with such exquisite precision that I have no idea where I am.
    1. Re:See It Now by Radhruin · · Score: 1

      I doubt the brain is telling the fingers to spread to an absolute unit of length, but rather relative to some object. In both cases, just large enough to grasp the circular object, however large it might be.

    2. Re:See It Now by residue · · Score: 1

      Yes, and "however large it might be" is exactly the issue!

      If one seems larger than the other, then you would assume that your fingers would spread to slightly the wrong size. Brilliant experiment, GP!

    3. Re:See It Now by hyades1 · · Score: 1

      This works just as well on a completely featureless background, though it makes the whole thing a bit more trouble to pull off. In fact, I'm pretty sure that's how the psychologists who set the test up originally had it set up. The only "objects" available for reference were the surrounding disks.

      --
      I've calculated my velocity with such exquisite precision that I have no idea where I am.
  24. By Neruos by Anonymous Coward · · Score: 0

    Nothing new here. The blind people who have hearing, normally gain heighten hearing after awhile. This in turn, develops out to like sonar. You know how you feel someone sneaking up on you, although you don't hear or see them (but you have that sense that someone is there). That is echoing presense.

    A blind person with no visual input or noise input, can not navigate unless they have a start, finish and repeation.

    1. Re:By Neruos by FishWithAHammer · · Score: 1

      Except they said they ruled out echolocation. Read the goddam article.

      --
      "You can either have software quality or you can have pointer arithmetic, but you cannot have both at the same time."
    2. Re:By Neruos by jcr · · Score: 1

      For as long as I can remember, I've been able to tell when I was near a wall in a dark room, or with my eyes closed. I don't know if I'd describe it as sonar per se, but I can also tell if someone is standing close to me, no matter what our relative positions are.

      FWIW, the last time I tested it with a tone genererator, my hearing topped out somewhere around 25Khz. I'm sure it's far lower now, but I can still tell if there's a CRT monitor powered on anywhere within fifty feet of me or so.

      -jcr

      --
      The only title of honor that a tyrant can grant is "Enemy of the State."
    3. Re:By Neruos by ZERO1ZERO · · Score: 1

      regarding the CRT monitor. What exactly IS it? I can do this too. It's a high pitched 'whine' sound. But what makes that sound?

    4. Re:By Neruos by jcr · · Score: 1

      CRTs tend to make noise at the frequency of their horizontal sweep, due to EMF from the changing magnetic field in the deflection yoke. For a TV, that would be 15.75 Khz. There would also be some noise at lower harmonics of that frequency.

      -jcr

      --
      The only title of honor that a tyrant can grant is "Enemy of the State."
    5. Re:By Neruos by Anonymous Coward · · Score: 0

      I wasn't aware we could hear magnetic fields. I wasn't even aware that the low fields in TVs and monitors could modulate air directly. And here I thought it was because the coil was moving and vibrating. Silly me.

    6. Re:By Neruos by jcr · · Score: 1

      I wasn't aware we could hear magnetic fields.

      You can't. What you hear is the noise made by the small amount of motion in the deflection coils.

      -jcr

      --
      The only title of honor that a tyrant can grant is "Enemy of the State."
  25. This works because... by Col+Bat+Guano · · Score: 2, Interesting

    ...the brain has a layered architecture. The more primitive brain has its own visual processing system. Evolution has built connections with this system and the parts of the brain that deal with awareness. Lose this connection and you can still "see", but not be aware of them (at a very high level).

    1. Re:This works because... by gregbot9000 · · Score: 1

      So this is like how Zombie's see then?

  26. Video of the experiment - from BBC by iammani · · Score: 4, Informative

    Heres a video of the man walking through the obstacles - from BBC
    http://news.bbc.co.uk/2/hi/health/7794766.stm

    Ps: Found this after 'Submit'ting to slashdot

  27. Re:BSD's final Christmas by Anonymous Coward · · Score: 0

    That was actually kinda sweet.

  28. Re:It's Ch'i energy by justinlee37 · · Score: 1

    We sense it. We transmit it. Assuming we've solved all the mysteries of the body is naive.

    I think you are the one making "assumptions."

  29. Video at NPR by eefsee · · Score: 2, Informative

    A video of the blind man walking down the corridor accompanies this story at National Public Radio.

  30. How old are you? by Anonymous Coward · · Score: 1, Insightful

    Take away a 50+ yo man's sight, and in most cases he won't be compensating all that well with hearing. It's partly accuity -- us old farts don't hear all those nice directional high frequencies as well as we used to; and it's partly about what it takes to learn a skill.

    Best to start early, because it will take years of practice to do it well and it may well be that your adult mind, after 50 years of primarily visual processing of spatial information, will have a hard time using auditory inputs for that purpose.

  31. Re:It's Ch'i energy by NinthAgendaDotCom · · Score: 1

    Let me just say, bahahahahahahahaha.

    --
    -- http://ninthagenda.com/
  32. Re:It's Ch'i energy by lena_10326 · · Score: 1

    Try astral projection (aka out of body). You can be successful with that and find personal proof.

    --
    Camping on quad since 1996.
  33. well how about smileys by vkoivula · · Score: 1

    Soon we are going to have a story of a blind man that reacts to smileys even thought he can't read.

  34. The Force? by Max+Threshold · · Score: 1

    Somebody check this guy's midichlorians.

  35. Bronikov-method by bvdbos · · Score: 1

    Isn't this a basic use of the Bronikov-method?

  36. Re:It's Ch'i energy by Anonymous Coward · · Score: 0

    Umm, it still does, on the level of sodium penethol: you condition yourself to drop your guard and you've effectively invited yourself to believe and create whatever you want. It will not change long-term behavior, but it will mess with your head when it tries to reconcile the conflicts in your memory.

  37. Re:It's Ch'i energy by cp.tar · · Score: 1

    His qidikeluoeryan count is off the charts!

    --
    Ignore this signature. By order.
  38. Re:My daughter confirmed this story for me a year by mutende · · Score: 1

    Look at this guy navigating by clicking his tongue: http://www.youtube.com/watch?v=NI9cGYWKs_8.

    --
    Unselfish actions pay back better
  39. vision without "seeing" is possible by Anonymous Coward · · Score: 0

    I used to suffer from severe migraine, migraine is NOT "just a headache", but a very unpleasant and disabling complaint that leaves you feeling very ill and disoriented with a severe intolerance to light, or, as in the case of my more serious attacks, I lost the use of my vision completely.

    the weird thing was that I could still move about (cautiously) and knew where a lot of obstructions where (even mobile things like doors or other people) but I couldn`t see a thing, just some sort of crazy disjointed fractal kaleidoscope effect that had no discernible relationship between what was going on around me and the muddle that was what I was "seeing"

    so my personal experience is that you CAN not see anything intelligible and still be able to detect things, it`s weird because you would think that seeing something was the act of knowing it was there, but at some level I think the brain treats "object" and "visual object" as different things, the information is probably split off before it gets to the visual cortex.

    I don`t think it had anything to do with "sonar" either, I could tell a person I knew was walking towards me from inside a building in a busy environment, no chance I could so much as hear their footsteps from inside with other people moving about, so I could not have recognised anything distinctive about their steps for example

  40. see it to believe it by mrbobjoe · · Score: 1

    "You just had to see it to believe it" said Beatrice de Gelder

    Oh now that's just cruel.

  41. Bilaterality of blindsight is special by GeertNimage · · Score: 2, Interesting

    It is not mentioned very clearly in the NYT article, but it is mentioned in the original Current Biology paper: this patient has BILATERAL lesions in both the left and right visual cortices. IMO, this is what makes this case especially interesting.

    Of course, blindsight has been demonstrated many times before, but always in patients with unilateral lesions. This has some methodological advantages (the patients can act as their own control), but the unilaterality has also been criticised. Maybe these patients make microsaccades, maybe some light is reflected by the nose into the other eye halves, etc. In short, maybe some information reached the intact hemisphere.

    This is not possible in the present patient, and that is especially interesting. AFAIK, this is the first and only patient with a bilateral blindsight.

    -- Geert

  42. I bet ya 5 altarian dollars that ... by nargileh · · Score: 1

    the obstacle avoidance rate would increase if you hire people with surprising bodies or opinions to leap out from behind the obstacle and exhibit and/or explain them at the crucial moment.

    1. Re:I bet ya 5 altarian dollars that ... by Dunbal · · Score: 1

      hire people with surprising bodies ... to leap out from behind the obstacle and exhibit

            Shouldn't make much difference to a blind person, unless the surprise has to do with certain smells...

      --
      Seven puppies were harmed during the making of this post.
    2. Re:I bet ya 5 altarian dollars that ... by marquis111 · · Score: 1

      Or, at the very least, if he tripped and fell towards the ground, he would miss it and end up flying.

  43. Move sig by jeric23 · · Score: 1

    AYBABTU. n/t

  44. Who modded this crap +5? by Viol8 · · Score: 0, Flamebait

    "By tapping into the secondary pathways like this, I can "see" about twice as well as most people in the dark"

    Mate, you're not tapping into anything. Everyone has varying night vision - it all depends on the number of rods you have on your retina and how well your eyes adapt to low light. So give it up with the night vision powers BS , you don't have it.

    As for people seeing in infra red - err , no. That would require a major structural change to the rods or cones which wold require a common but as yet undiscovered genetic mutation. Apparently we all have some ability to see the very near infrared if the source is extremely bright but even that only extends a short way down.

    "Since the average person's brain normally focuses intently upon just a small area in front of them, expanding that to your entire field of vision makes a huge difference."

    Right , because normal people never see something out the corner of their eye as they only ever concentrate on whats right in front of them. Yeah , to see stuff in peripheral vision you need months of l337 training! Not. If we didn't notice stuff in our peripheral vision all our ancestors would have been eaten by lions millions of years ago and we wouldn't be here to have this dicussion.

    1. Re:Who modded this crap +5? by Plekto · · Score: 1

      Mate, you're not tapping into anything. Everyone has varying night vision - it all depends on the number of rods you have on your retina and how well your eyes adapt to low light. So give it up with the night vision powers BS , you don't have it.
      ****

      The "trick" here is to use more of your eye consciously by de-focusing enough so that you block out the horribly distracting and bad in low light fovea(center of your vision). Think of it as learning to utilize more of the data that is coming into your eyes. People talk about how blind people typically amplify their other senses. It's possible to do this with any sense over time, even if the others are undamaged. I'm not seeing in the dark so much as using my brain's ability to turn up the gain.

      ****
      As for people seeing in infra red - err , no. That would require a major structural change to the rods or cones which wold require a common but as yet undiscovered genetic mutation. Apparently we all have some ability to see the very near infrared if the source is extremely bright but even that only extends a short way down.
      ****

      I mentioned body temperature because all of our senses fall within narrow ranges. But they all differ. Some people can hear upwards of 20khz. Some cannot hear low frequencies at all. People have varying body temperature set points. Mine is at 97.8. If I'm at 98.6, I'm running a slight fever. The same is true for the structure of the eyes as well as color vision. Some people see a tiny bit farther into the infra-red than others. Some people see four *primary* colors. Some see only two(color blind).(what I meant by "4 colors" in my post - my bad) The most obvious one, though, is how some people have an extra set of taste buds that react to bitter tastes. That's quite well known. The trick is to figure out what senses that you have that are slightly better than the norm and tapping into them. After all, the objective here is to not hit things. Not to actually "see" objects in low light.

      Another interesting thing about this is that do you notice how you almost never actually run face-first into something in the dark? You almost always bump against it or bang into a corner.

    2. Re:Who modded this crap +5? by Viol8 · · Score: 0, Redundant

      "Some people see a tiny bit farther into the infra-red than others"

      No , they don't. Fact.

      "Some people see four *primary* colors"

      None of which stretch into the infra red.

      "You almost always bump against it or bang into a corner."

      Yeah , right. Why not RTFA - the guy didn't do the test in the dark - his eyes were receiving the light and sending it to part of his brain , just not the part the part that produces concious sight. He didn't have some magic 6th sense and neither do you so cut the BS.

  45. As a long time Anonymous Coward... by Anonymous Coward · · Score: 0

    I'm appalled at the retarded posts on this one. This may be the first time an article was slashdotted without any noticeable increase in traffic.

    He walks down the hall in silence! Even the best cases of echolocation require that the person make a repeated noise. He's avoiding little objects on the ground! I'd love to know if his eyes are tracking objects in the room as well.
    The article also states that the man reacts to pictures of faces. If the article is authentic, he is receiving visual stimuli, but only in the form of a subconscious "itch." The real test would be to blindfold him or turn out the lights.

    For me, this article really changed how I think about the potency of subconscious messages. What if we mastered the art of embedding artifacts that were more detectable to the subconscious brain than the conscious one? How well could we be manipulated? Could we teach Slashdotters to RTFA?

  46. Sight? Or Statistics? by MaliciousSmurf · · Score: 1

    What the story fails to mention is the 254 other blind men who failed to successfully navigate the maze. Go statistics!

  47. similar to when motor cortex is damaged by similar_name · · Score: 1

    It seems this is very similar to when the motor cortex is damaged and rehab trains another part of the brain to take over that function. Perhaps a similar rehab regiment for visual cortex damage could be thought up. Start simple, and grow from there. Maybe large basic shapes and colors and over time making them a little more complex.

  48. Re:It's Ch'i energy by mpeskett · · Score: 1

    And one would assume that you could demonstrate it in some way, maybe tell us something you saw that you couldn't otherwise see while under scientific scrutiny, and do so with a greater-than-chance frequency.

    'cause y'know... if it's real I would assume that it's measurable or demonstrable in some way, otherwise the simpler explanation is that you're having a very vivid dream.

    I know similar studies have been done and I'm still waiting for the one that will make scientists realise they've been wrong all along (don't get me wrong, I think it would be great if you could prove this stuff rigourously, but until that happens I have to remain skeptical)

  49. This reminds me... by Anonymous Coward · · Score: 0
  50. I didn't read the article yet somehow... by Anonymous Coward · · Score: 0

    I didn't read the article yet somehow I feel that I have, and more importantly, am able to comment.

    It's a strange phenomena. As if the article were hovering before me as I type. Worthy of more research I'd say.

  51. Re:My daughter confirmed this story for me a year by LenE · · Score: 1

    My daughter, who is now four years old, is very attuned to large spaces that echo. She can hear them coming and as she approaches, she usually shouts "Ha!" to hear it come back to her.

    That being said, she doesn't need to click her tongue to sense walls and such. Even in quiet rooms, there is enough ambient noise from her motion and things around, that she can sense the location and more importantly the nearness of objects. When she "looks" at something, she is rarely looking straight at it. She lowers her head and leans one ear closer to the object. It is difficult for extended family members to understand this, as she has perfectly good eyes, but they rarely are looking at whatever she is focusing on.

    Her stroke has left her with some other side effects. She is developmentally delayed and suffers some moderate cerebral palsy. It is not easy for her to clearly repeat words back to us. Still, it is absolutely amazing to see how refined her sense of hearing is, with regard to overcoming her diminished vision.

    -- Len

  52. funny, that's exactly what the prisoners said by Anonymous Coward · · Score: 0

    in Plato's Cave Allegory

  53. Intuition as a sixth sense? by Anonymous Coward · · Score: 0

    Visual perception can be fooled

      (e.g. place an oar or a stick into the water, it looks bent. But you know the stick is straight. How do you resolve this?)

    So humans must have evolved other ways to ferret out the truth when nature (or predators) are attempting to fool their eye.

    That's probably why you spot a con artist after a few moments in close proximity. Something "doesn't smell right" or it just "feels funny".

    Certainly we lose alot of integral information through the lossy medium of television. So many things occur in-between those 30 frames per second (micro-expressions) and the illusionists have used instant replay to their advantage by continually adjusting the bent oar until it appears straight on our tell a vision.

  54. Give the man acid by KillerRobot · · Score: 1

    ...or some mushrooms. Maybe he will someway be able to be more conscious of the visual stimuli in an altered state, giving more insight on what is happening.

  55. Science can be a religion too; and have its flaws by bussdriver · · Score: 1

    Question a religious person's beliefs and you get a response proportional to the strength of their beliefs.

    Rigid science types are no different; it really is similar to religion. As an atheist, I can make this connection from personal observation.

    Science is a philosophy and because humans are involved, it has problems with dogmas etc forming around it despite its nature of discouraging all that baggage.

    Plenty of things are not tangible; and plenty of of observations are fuzzy and have too many variables that can not be removed. "Soft" sciences must contend with the limitations of science far more than "hard" science; not surprisingly many hard science types shun soft science as if they somehow have a better understanding of science when they are safely within its bounds in their work and never have to venture out into the border areas of science.

    Take the human mind. We will never figure it out completely (its a 10**14 node network to begin with.) Exploration of the human mind is not very testable stuff nor is it that tangible either. The complexity results in even correct answers being too broad or being between random and the margin of error - making it near impossible science. Yet, enough of these really really soft science answers have been applied and used on people-- making psychology far more dangerous than physics.

    I've seen a leading expert at a convention on primate behavior trying to argue they are conscious like us. Describing how strict science can't provide an answer while half the room got upset. The videos I saw were convincing; one couldn't do anything better than with a human child. It was subjective opinion and science couldn't help the matter.

    Science isn't that young; it has a long history of shunning the truth before accepting it.

    Ghosts don't exist. But I'm open to seeing if one can find the answer. Could be there is a totally different unknown explanation for why some people experience odd events (even if its just in their mind; thats not a end point but likely an even bigger question.)

    Hypnosis is odd stuff. Exploring one's own mind in a totally odd way that provides another perspective. Hard science rejected hypnosis and soft science did as well it even existed for a long time outside of the realm of science; now they've studied it and feel that they know it. (which is another topic... overconfidence.)

  56. Use of echolocation by blind people by Anonymous Coward · · Score: 0

    You seen this? The youtube link below shows a blind kid that has trained himself to use echolocation. He makes clicking noises while... listening very carefully. Here's the link.

  57. Re:My daughter confirmed this story for me a year by Mal-2 · · Score: 1

    I'm not surprised by the fact that her poorly processed vision can actually be a hindrance at times. Personally, if I try to walk through an unfamiliar dark room (whether it's really dark or my eyes just haven't adapted yet), I'll fumble around and walk haltingly. If I close my eyes, it's like my brain "gives up" on trying to use the eyes, and much of the weirdness goes away. I may still walk into things, but I'll do it with confidence.

    I think your daughter might be better off just closing her eyes when they are more of a liability than an asset. I can't see how it would hurt to try, in any case.

    Mal-2

    --
    How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.
  58. Re:My daughter confirmed this story for me a year by Reziac · · Score: 1

    She may also be sensing air currents with the fine hairs on her face and neck.

    One of the ways you can readily spot a blind cat is that it will ALWAYS keep its whiskers stretched forward -- not to touch things with, but to sense micro-currents that surround objects, so as to avoid running into them. These cats can be good enough at it that their owners won't believe the cat is blind. I once had a very old cat who was both totally blind and stone-deaf, and he navigated entirely via this whisker-based "air sense" (and did very well that way for 6 years, til he got senile at age 18, and lost his ability to navigate.)

    --
    ~REZ~ #43301. Who'd fake being me anyway?
  59. Triune brain by Anonymous Coward · · Score: 0

    Yes, the phenomenon of blindslight would seem to lend support to the Triune Brain theory.

  60. Blindsight is an extraordinary ability by Veggiesama · · Score: 1

    Everyone knows that blindsight is an extraordinary ability, which can be used to operate effectively without vision. It might be a form of sensitivity to vibrations, acute scent, keen hearing, or echolocation. It even makes concealment and invisibility (even magical darkness) irrelevant to the creature with blindsight.

    Don't believe me? Well, it's RAW.

  61. here comes daredevil by Icegryphon · · Score: 0

    Will I start having a attraction to jennifer garner as well?

  62. Re:It's Ch'i energy by lena_10326 · · Score: 1

    Not everything must be proven with a confidence of 1.0

    --
    Camping on quad since 1996.