Brain and Blindness...

INRM

Philosopher
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Okay, Alan Alda did this bit on this TV show yesterday...

in it, it was about how the human brain works.

This italian guy was trying to make the point that the brain can be re-configured to behave differently. They had this girl blindfolded for 100 hrs. Totally.

It turned out that the part of the brain that processes touch was re-routed to the visual cortex (i.e. The visual cortex was working to process the sensations from touch).

When they did some kind of electro-stimulation to disrupt the visual cortex, and had her read-braile. She had difficulty processing it.

THis was done back in 2,000. Do you have any more data what I'm talking about...

Also, the end results, they had her take the blindfold off. Get re-adjusted to walking around normally. Then put it back on and see what happened. I'm not certain what happened. Did both her normal areas for touch AND the visual cortex work to process touch, or just her normal areas for touch?

I'm not certain

-INRM
 
No clue.

I googled around a little, and in one place that looked like it might have some relevant info, I got overwhelmed by a plethora of polysyllabic terminological esoterica, a sample of which follows:

"...NMDA receptors and the voltage mediated magnesium block, calmodulin kinase, nitric oxide and arachidonic acid as putative retrograde messengers, associative LTP..."

Whew! Those dudes are really gettin down!

Anyway, this reminds me of that thing where the subject wears a special set of glasses (prisms) that flip the image, so everything appears upside down (reversing the inversion done automatically to compensate for the fact that the lens of the eye naturally flips the image). After a day or so (or however long it was), the brain compensates for the inversion, and the subject sees everything normally. Then, when the glasses are removed, the subject sees everything upside down again for a while, until the brain once again compensates.

It's an interesting subject. The degree to which the brain is able to contrive work-arounds to compensate for impairment or loss of function of various components is amazing.
 
I saw that program about six months ago. I think what it demonstrated was that the brain can reconfigure itself so that different parts could do different jobs, if necessary. I forget the exact details.

Did you have a specific question about the program?
 
RichardR said:
I saw that program about six months ago. I think what it demonstrated was that the brain can reconfigure itself so that different parts could do different jobs, if necessary. I forget the exact details.

Did you have a specific question about the program?
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YES!!! That's the program!

My question is...

After she took the blindfold off, her brain reverted to it's previous function right?

When they put the blindfold back on, right on the spot. Did her brain continue functioning the way it originally did, or did it revert to the way it did when she had the blindfold on for 100 hrs (i.e. her visual cortex handling sensory inputs from her fingers).

Or did it work both ways (i.e. BOTH the normal areas for sensory input AND the visual cortex handling visual input).

-INRM
 
INRM said:
After she took the blindfold off, her brain reverted to it's previous function right?
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Right.

INRM said:
When they put the blindfold back on, right on the spot. Did her brain continue functioning the way it originally did, or did it revert to the way it did when she had the blindfold on for 100 hrs (i.e. her visual cortex handling sensory inputs from her fingers).
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As I recall, after only a few hours without the blindfold, her brain wouldn't work the way it did after the week of blindness. In other words, the eyes quickly took back their part of the brain.

At least, that's how I remember it.
 
Dymanic said:
.....this reminds me of that thing where the subject wears a special set of glasses (prisms) that flip the image, so everything appears upside down (reversing the inversion done automatically to compensate for the fact that the lens of the eye naturally flips the image). After a day or so (or however long it was), the brain compensates for the inversion, and the subject sees everything normally. Then, when the glasses are removed, the subject sees everything upside down again for a while, until the brain once again compensates.
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I'm pretty sure that the subjects did not report that they saw everything normally after a while. It was more along the lines of "we adjusted to everthing being upside down" or "we no longer needed to mentally flip everything the right side up to work out what was going on" etc.

Also, when the glasses were removed, they did not see everything upside down. It was more that they now needed to adjust to everything being the right side up just as, previously, they needed to adjust to everything being upside down.
 
I heard somewhere, probably on some program, that if a child is totallly blind after a certain age, no matter if the problem is fixed, he will never be able to see. I believe the age was 4. Anyone heard of this?

I also wonder, which would be easier to overcome? Getting hearing for the first time or eyesight. I would imagine with hearing it would be hard to understand language especially if one is older. But with gaining eyesight would the person always have problems with depth perception etc? A person that has always been able to hear is able to tune out irrelevent noise, can this skill be learned by someone who has been deaf until adulthood?
 
My understanding is that there is a set time in which brain development for sensory perception must occur and once this time has passed, that function is lost or impaired. The area of the brain normally devoted to, say, vision, would be utilised for something else.

This was determined in experiments on kittens. New born kittens were raised in an environment where they saw only vertical lines, for example. After a certain age, kittens could not perceive or learn to perceive horizontal lines or lines at a 45 degree angle.

The daughter of a family friend had chronic ear infections as an infant that were not treated by their family doctor. It was not known that her hearing had been impaired and consequently, her language skills were severely affected. As the problem was discovered after she started school, the critical time in which that part of her brain was developing had passed. She has ongoing difficulties with language and learning to such an extent it is unlikely she will ever lead an independent life.
 
Denise said:
I heard somewhere, probably on some program, that if a child is totallly blind after a certain age, no matter if the problem is fixed, he will never be able to see. I believe the age was 4. Anyone heard of this?

...
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I read this on one of Oliver Sack's books. It involved a man who was blind, but at the urging of his fiance/wife underwent a procedure to make his eyes function. His brain did not know how to process the information.

I "think" is was from _The Man Who Mistook His Wife for a Hat_ (though it could be _The Anthropologist from Mars_ ... I'm sorry I cannot remember, and I have not read the book about the Island of the Color Blind).

I saw that this story was made into a movie. I did not see that movie (it was panned in the reviews). But reading the essay does give a bit more insight into what happened. Especially since Dr. Sacks gives some information as to why it happened in such a manner that a layman like me could understand.
 
spoonhandler said:
...The daughter of a family friend had chronic ear infections as an infant that were not treated by their family doctor. It was not known that her hearing had been impaired and consequently, her language skills were severely affected. As the problem was discovered after she started school, the critical time in which that part of her brain was developing had passed. She has ongoing difficulties with language and learning to such an extent it is unlikely she will ever lead an independent life.
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Fortunately there is ongoing research showing that with good intervention there is more hope for language impaired kids. Even if intervention is delayed (usually by well meaning but clueness folks who take the "wait and see" approach) there is PROGRESS.

It also helps to know where to get good therapy... and what parents' rights are in education.

Also, if there is language impairment past the time when hearing is thought to be affected, there may be other factors. It also depends on how good the therapy is. If taken at face value, the above statement would imply that most deaf and hard of hearing people were not independent. Fortunately, that is not the case. (Good book: _Train Go Sorry_ by Leah Cohen, http://www.amazon.com/exec/obidos/t...103-2363460-4366203?v=glance&s=books&n=507846 )


Good references on speech and language disorders is _Childhood Speech, Language and Listening Problems_ by Patricia McAleer Hamaguchi:
http://www.amazon.com/exec/obidos/t...103-2363460-4366203?v=glance&s=books&n=507846

Other good resources are:
http://www.asha.org/index.cfm

and the one I have used for my seizure affected child (and why I have immersed myself in books on neurology and speech/language disorders):
www.apraxia-kids.org
 
I think the main problem was that at the critical time, no one appreciated that the girl had impaired hearing. If it had been known, other steps could have been taken. I certainly did not intend to suggest that impaired hearing leads to lack of independence. Now, as a teenager, the girl has excellant hearing. She has received a great deal of treatment, including surgical, speech therapy and remedial teaching. However, the problem remains that her language and speech centres did not develop correctly. The problems are complex, but combine to make it difficult for her to carry out tasks most of us take for granted.

The story of the blind man told by Dr Sacks was really interesting. The man found it horribly confronting to deal with information he had no apparatus for understanding. Part of that story recounted how the man frequently closed his eyes to carry out tasks like shaving so as to avoid the distracting input. He also wished he had never had the treatment. Everyone around him took it for granted that sight would be a wonderful gift.
 
Just a few comments. There are a great many areas in the brain that are visual areas. There is simply no way that all (or even most) of them would get rewired to process a different sensory modality in 100 hours. Not even close. I'm guessing that what actually happened was that one (or a few) of the many visual areas (probably at a very high level of sensory processing) was rewired.

That said, it certainly is true that the brain has an incredible ability to rewire itself, particularly in young persons. Even old folks' brains can rewire themselves to some extent, though. That's why stroke patients can often recover some of the functions they initially lose.

INRM said:
Did both her normal areas for touch AND the visual cortex work to process touch, or just her normal areas for touch?

I'm not certain

-INRM
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The normal somatosensory (touch) areas still worked to process touch, I'm sure. I should also mention the fact that there are some areas that process information from more than one sensory modality. I wonder if maybe it was one or more of those areas that was rewired? My reason for suggesting that is that 100 hours isn't all that much time for major reorganization, and I know that such areas DO get reorganized fairly quickly in response to sensory deprivation.

Anyone happen to catch the name of the area(s) that were reorganized?
 
I can't speak for all of the senses, but I know for hearing, if a person is deaf from birth, and there is no way to get neural signals to the brain very quickly, even a perfect repair of the problem after about age 3 or 4 will not provide normal hearing ability.

You have to get it YOUNG.

Kids who were deafened by disease at 2, and healed at 20, on the other hand, seem to be able to learn how to hear. It appears to be a question of connections never made while young and still adaptable.
 
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