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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."
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....
Blindsight is 20/20.
TFA specifically states that they ruled out echolocation.
Always going forward, 'cause we can't find reverse.
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.
http://en.wikipedia.org/wiki/Zatoichi My favorite Japanese movies. Gotta love Shintaro Katsu's portrayal of a blind man.
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
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."
For those whose curiosity hasn't entirely been replaced by fashionable knee-jerk skepticism, your optic nerve does not only terminate in what we think of as primary visual cortex, it sends projections to other areas as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"
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.
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.
...FTW.
THL phish sticks
From bugmenot.com:
Username: arizonafrank
Password: poochie
No existe.
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
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
Obi-Wan Kenobi would be proud.
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
RTFA and you'll see your wrong
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.
...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).
.
Congratulations, you found the point of the article. Many have failed to do so.
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
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."
A video of the blind man walking down the corridor accompanies this story at National Public Radio.
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."
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.
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.
Let me just say, bahahahahahahahaha.
-- http://ninthagenda.com/
Okay, that's what I get for not using preview! The correct site is here
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."
Try astral projection (aka out of body). You can be successful with that and find personal proof.
Camping on quad since 1996.
Soon we are going to have a story of a blind man that reacts to smileys even thought he can't read.
Somebody check this guy's midichlorians.
Isn't this a basic use of the Bronikov-method?
His qidikeluoeryan count is off the charts!
Ignore this signature. By order.
Look at this guy navigating by clicking his tongue: http://www.youtube.com/watch?v=NI9cGYWKs_8.
Unselfish actions pay back better
Oh now that's just cruel.
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
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.
AYBABTU. n/t
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?
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."
What the story fails to mention is the 254 other blind men who failed to successfully navigate the maze. Go statistics!
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.
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)
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
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.
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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.
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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.
...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.
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.)
Democracy Now! - uncensored, anti-establishment news
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."
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.
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?
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.
Not everything must be proven with a confidence of 1.0
Camping on quad since 1996.