Justin Feinstein six years fought hard to scare a guinea under the code SM. He showed her the "Blair Witch Project", "The fear of spiders," "The Shining" and "The Silence of the Lambs" — it is useless.
He took her to the shop of exotic animals, but it has no apparent reason pulled the snake out of the cage and enthusiastically finger touched her tongue. It was only due to the intervention Seller she could not make friends with a cute tarantulas.
Then Mr. Feinstein took her to an abandoned sanatorium Waverly Hills — "the worst house in the world", according to the leaflets. Servants of the attraction regularly include strange noises and eerie music, and the actors struggled portrayed killers, monsters and ghosts, but she just laughed appreciatively when other tourists screamed in horror. Moreover, she accidentally managed to scare one of the "monsters" out of curiosity when she tried to touch his head.
Fear Factory — the amygdala of the brain — the SM is missing.
Mr. Feinstein, a clinical neuropsychologist, California Institute of Technology (USA), for this example, trying to understand how our brain is born of fear. Benefit from it — the sea. For example, you could develop effective treatments for post-traumatic stress disorder.
SM has attracted the attention of scientists when knocked to the laboratory neuroscientist Daniel Trenela at Iowa State University (USA) in the mid-1980s. She was just diagnosed with "disease Urbach — Vita". It is a genetic disorder so rare that today is known less than three hundred cases. Among the symptoms — cutaneous lesions and calcium deposits in the brain. In SM disease destroyed both the amygdala.
"It is so localized lesions is extremely rare — said neuroscientist Daniel Kennedy from Indiana University (USA). — Such cases are only a couple of dozen. " Seeing this, Mr. Trenel realized that he had the unique opportunity to study the function of this brain region.
Amygdala (one in each hemisphere) play an important role in the formation of emotions, especially fear. It has long been known, but the details are vague. In particular, the scientists can not yet say how the amygdala are necessary for fear, said Mike Koenigs at the University of Wisconsin-Madison (USA). Perhaps, the activity of the amygdala, recorded tomography — just the result of the activity of other brain areas.
It seems to be the case SM exclude this possibility, because along with the almond-shaped bodies, it is completely the feeling of fear, while the rest of the emotional palette has not changed. However, it features extremely lively. You could say it in a way chasing new sensations. Once scientists invited her to a restaurant where she gladly chatted with the waiter, and the next day asked to take her to the same place. Seeing the same server, she visibly brightened and was with him extremely affable.
This is a sign that, unlike most other people, SM is not able to recognize the subtle cues that cause us to behave in a more restrained in certain situations. "The people that you and I would have seemed shady characters, she would have called you trust — said Mr. Kennedy. — It discriminates against people in the sense that all want to get close. " Apparently, the amygdala are responsible not only for the fear as an emotion, but also some aspects of human behavior.
Mr. Kennedy recently checked the degree of openness of SM by the example of her sense of personal space. He asked the women to slowly approach the SM, and that was to give a sign when it starts to feel uncomfortable. This boundary is located at a distance of 0.34 m from it, that is almost twice closer than the other participants in the experiment.
Moreover, it was found that the SM is not able to read facial expressions, but it can not selectively: it sees joy and sorrow, but can not identify the fear. And it is a subconscious reaction: face, distorted by fear or anger, mixed with personal expressionless faces appeared on the screen for 40 ms, and from SM required to press a button as quickly as possible when a person, who expressed more fear than anger. With this task is handled much the same as the others. But when she was given unlimited time to think, she was wrong.
Digging a bit deeper, Mr. Kennedy found that the problem is how the brain directs her gaze. SM just does not look in people's eyes when they see the fear, that is, when they are expanding. When it was put in such conditions, that she could not look into her eyes, she became more correctly determine a person frightened people.
Thus, the amygdala — is not just a "danger detector." The danger seems to be recorded in other areas of the brain, the amygdala and the results of this work guides our attention to gather critical information about the degree of danger. The result is a feeling of fear. And since SM amygdala were absent, she felt only excitement akin to a sense of excitement, but do not fear. This explains the fact that the pet store in the "haunted house" she was not indifferent, as would be expected of a fearless man.
But Mr. Feinstein took to her destroyed this coherent theory. He finally managed to scare the poor thing.
In one experiment, it was joined twins AM and BG with identical injuries amygdala. Mr. Feinstein addressed to the classic test for a panic asked the participants to wear masks, in which air was supplied with a 35-percent carbon dioxide content. Most healthy people immediately begin shortness of breath, quickens the heartbeat, perspiration, dizzy. About a quarter of panics.
Oddly enough, all three also experienced panic. SM waved her hands pointing to the mask, and cried out, "Help!" When the mask was removed, she said: "I panicked, because, dammit, do not understand what's happening." For the first time since the beginning of her illness she experienced fear.
Two others have reacted almost the same way. AM grimaced and clutched his left hand into a fist, trying to get free. According to her, she was afraid that would choke, and I noticed that it was the most terrifying moment of her life. BG was gasping for air and unmasked herself, confessing later that he felt something completely new — the fear of imminent death.
After this, Mr. Fayntshteyn did not know what to think. For decades, the couple described the amygdala of the brain as the center of fear, and it seemed natural that in their absence, a person becomes a desperately brave.
However, the scientist will soon come to the conclusion that the old theory is not so wrong. Apparently, the brain processes the different threats posed inside (asthma, heart attack, etc.). "This is the primary layer, the basic form of fear" — emphasizes Mr. Feinstein. Indeed, there is no reason to note strain and assess the environment: a high level of carbon dioxide in the air breathed directly alters the acidity of the blood, causing a cascade of reactions in the brain. Therefore, there is panic and without the "tonsils" — probably somewhere in the hypothalamus and periakveduktalnom (central) gray matter.
And here it is necessary to pay attention to this important point. People with almond-shaped bodies, understand that this is a scientific experiment that scientists will not happen terrible. That's why they have another panic. In this case, however, the trio has experienced the most that neither is true horror of dying. They were not able to properly interpret the scope of their excitement.
The role of the amygdala in the risk assessment and explains another strange result of these experiments. In healthy participants, as a rule, there is a pro-active response by repeating the test: before re-donning their changing nature and sweating slightly quickens the heartbeat. Volunteers with the disease Urbach — Vita second time behave fearlessly as in the first. Consequently, the amygdala is responsible also for the preservation of the memories of the horrors.
It is interesting that in a sample of 200 Vietnam veterans with traumatic brain injury none of the patients with damaged "tonsils" has acquired post-traumatic stress disorder.
So to work with this area of the brain should be very careful. On the one hand, because of it we can not get rid of painful memories, on the other — it protects us and teaches us to continue to avoid the dangers. Deprived of its SM once admitted: "I would not wish anyone to this."