Blindsight reveals the teachings of the ancient mysteries of the brain

26.12.2008

After the experience of the new ward scientists, according to his wife, began to move a little easier. But it still feels and behaves like a blind man. However, the patient intends to continue training on how to recognize the location of objects (Figure William Duke).

Sounds like quackery, but it is a medical phenomenon. A person found to be 100% blind, runs a maze with obstacles. Not by ear and by feel. The patient states that it does not see nothing, but only knows intuitively where to step. Doctors also explain — we are all the same specific form view, but works on a subconscious level.

At first we took this post with a grain of salt. Oh how we saw the "psychics", finding something blindfolded. I remember, in particular, shows a lady Sentient color hands. Misty history, mainstream science has not deciphered.

Only here the new hero does not claim to be psychic or sixth sense. 56-year-old resident of Burundi, known as "code" TN, is not looking for fame. Even in the video, filmed during the experiment, his face veiled by special effects.

As a doctor, TN and he understands that we have to deal with some bad investigated the possibility of a hidden until the brain. That's all. But for scientists who study the phenomenon it is "that's all" — a true miracle of nature.

But before I tell you about the sensational experiments with TN, to explain what kind of blindness he suffers. Because of two strokes he completely destroyed the visual cortex in both hemispheres, although other parts of the brain have remained virtually intact. Now the eyes of TN healthy and continue to send signals to the brain, but there is nothing to recycle them.

Physicians know many patients with a similar diagnosis. However, usually suffers only visual cortex in one hemisphere and therefore lost vision in one eye. TN is blind on both eyes and is the first person with such damage, as described in the scientific literature. Moreover, the lack of activity in the visual cortex of his tomography confirmed, so that "yes he's peeking!" — Does not pass.

TN unique? Not really. And that is just what makes it a case is particularly valuable for science.

The fact that the medical long known phenomenon of the blind (blindsight), observed in patients with a similar brain damage.

It consists in the following: people demonstrate (in the experiments with a strictly controlled environment) some responses to visual stimuli, despite the fact that the claim — can not see anything.

For example, patients with vision in one eye is shown in the "field of the dead" are different things. And patients recognize their absence or presence, sometimes even featuring a large O of X. And yourself experimental explain that just "guessing blindly", that's just the percentage of correct answers is higher than on the theory of probability.

Scientists argue: the phenomenon of blind view, we are dealing with a simple processing of visual information outside of the visual cortex, the signals are bypassing and involve certain ancient parts of the brain, usually unused.

It happens on an unconscious level, but the visual information, albeit in a primitive form, has an impact on a person's choice. Although in terms of visual sensations — solid black in front of him. That is, the objects as such person does not consciously see but feel them.

Abilities TN has long attracted the attention of researchers. In 2004, we reported on an unnamed blind patient, the ability to discriminate emotional expressions of people's faces, not perceiving them visually (that is, in his mind there was only a "black screen").

Then it was a question of TN. And even then conducted a recent study that same scientist as the current — Alan Pegna (Alan Pegna) of the University Hospital of Geneva (Hôpitaux Universitaires de Genève).

Now, together with Beatrice de Gelder (Beatrice de Gelder) from the University of Tilburg (Tilburg University) and a number of colleagues from different countries Alan TN asked to put aside his wand and try "just" go down the hall.

"At first he was nervous, he said that he would not be able to do this because blind" — says de Gelder. Still, a blind man was impeccably route, maneuvering between the wall and stand away from the camera, a variety of small objects scattered on the floor.

TN downward. He did not see anything consciously, but somehow feeling recognize obstacles. After the double passage corridor scientists awarded the ward applause. It is interesting that he TN, when he was told that he had just done (after all the obstacles he was not informed in advance) — was very surprised.

Maybe it's echolocation? Echoes of the steps, and even his own breath could tell the blind, where the objects.

Beatrice says — this is not the answer. The fact that the sonar is not working with small objects. In other words, the resolution of the "Sound of view," perhaps, would help TN does not crash into the wall, but did not get around lying on the floor of the book.

One of the experts in the blind sight, did not participate in this study, commented, "It looks like in the real world, we can use the signals in the brain that are totally unaware of." Perhaps we are talking about the ancient parts of the brain are usually not involved in such an unusual quality. But what means are used here — is still unclear.

Researchers speak of "ancient," raw "form of vision, similar to our reaction to flying in the face of the subject (we shrink before we consider it.) And yet — that we, the sighted, in many situations, acting in obedience a kind of unconscious motives, which are not thought of.

In some cases such behavioral responses may be associated with visual sensations, but not those that are "on the screen" shows our minds visual cortex.

Details of the new article reveals the experience of the authors in the journal Current Biology. And this scientific work is a stark contrast to the history of the Sentient color fingers women: the one to his scientists to gun shot did not admit.

TN also, according Pegny, showing great interest in the study of himself and wants to help scientists understand the phenomenon of blind sight. But as far as this knowledge will help other blind people with the same diagnosis — you can still only guess.

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