For the first time scientists have succeeded in demonstrating how a brain region called the amygdala, is essential to induce fear in humans. Researchers at the University of Iowa, USA, described the case of a woman whose amygdala, an almond-like structure in the brain was destroyed because of an disease.
scientists watched as the patient, identified only as SM, was unable to respond to stimuli from fear of snakes, spiders, horror movies and even situations where his life had been compromised.
This confirms, experts say in the journal Current Biology, that the amygdala is essential to provoke a state of fear in humans.
Progress, they say, could lead to better treatments for posttraumatic stress disorder (PTSD) and other anxiety disorders. Process
emotions
For 50 years, studies have shown that the amygdala -Located deep in the temporal lobe, is responsible for the processing of emotional reactions, including fear.
But so far these studies have only been conducted with animals, from rats to monkeys.
Now for the first time, be able to confirm in a human.
"The nature of fear is based on the survival and the amygdala helps us stay alive by avoiding situations, people or objects that could put our lives in danger," said Dr. Justin Feinstein, who led the study.
"Because SM is not the amygdala, also lacks the ability to detect and avoid danger in the world. It's really special that is still alive, "adds the scientist.
The researchers carried out studies for several years with the patient. confirmed that it was unable to recognize fear in facial expressions, but even before this work was not known if he could to experience the emotion itself.
Answers To test this, Dr. Feinstein and his team observed and recorded the responses of women when exposed to snakes and spiders (two of the most commonly feared animals). Also evaluated and watching horror movies during a visit to a "haunted house".
how the patient was measured fear experienced a series of standardized questionnaires that examine various aspects of fear, ranging from the fear of death to the fear of public speaking.
addition, during a period of three months was submitted to His Majesty to an "emotion diary" computer, which was randomly qualify their level of fear at different times of day.
In all scenarios, "say the authors, the patient did not experience fear.
"And talk about your past experiences, described how he had faced many traumatic events that had threatened its very existence and yet, as reported, had caused no fear" experts say.
According to Dr. Feinsten, these results suggest that the human amygdala is a key area of \u200b\u200bthe brain to provoke a state of fear.
"While the patient is able to experience other emotions such as happiness and sadness, is incapable of feeling fear."
"This suggests that the brain is organized so that a specific region, the amygdala-specializes in the processing of a specific emotion: fear." Hide
amygdala
Scientists believe that this finding could lead to new treatments or mechanisms to achieve "off" the amygdala safely and non-invasive for patients suffering from disorders such as PTSD.
These therapies may help, for example, war veterans suffering from PTSD and whose lives are controlled by an ever-present fear in your life.
Unlike these individuals, says Dr. Feinstein, the patient in this study is immune to these states of fear and shows no symptoms of PTSD. "
"It is impossible that the horrors of life entering their emotional core. In essence, traumatic events do not leave an emotional imprint on your brain."
The scientist added that "in understanding how the brain processes fear in cases like that of SM, maybe someday we can create targeted therapies selectively to brain areas that allow fear to rule our lives. "(BBC)
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