Amygdala regions of both hemispheres of the brain damage she caused complete loss of SM fear.
Snakes, spiders, cockroaches and horror can cause terrible voice screaming howler in many people, but feel free there is not enough "xi light" to her SM - who have never felt fear.
The neurologist at the University of Iowa in Iowa City (USA) looked at her in 20 years, because she is one of very few people known to damage the brain amygdala (the amygdala) on both hemispheres. This brain region which has the role of information processing caused panic and other emotions.
Nucleus of her brain SM is broken by a rare condition, Mr. Urbach-Wiethe disease, which causes calcium deposited back and brain damage in that area.
To determine the effects of this disease, Daniel Tranel, a team member and her colleagues for SM exposure to things that often make women fear - spiders, snakes, a "ghost room", and horror clips.
As a result, she SM almost no expression of fear, although she still has the common sense like fun, happiness and sadness.
She also faced dreadful situations in the past, such as a gun, pointed knife and nearly killed in an accident at home. However, the researchers said, she said no fear in these situations. She was even able to realize that their fear is not unusual.
"It's amazing that she is the only rational response, rather than a physiological response. The body is not ready to create a physiological response because the amygdala has lost function," Dr. Jon Shaw, professor of psychiatry at the School of Medicine.
But researchers said the study Tranel, along with the response of the SM situation in the previous accident, that the amygdala plays an important role to create the fear of man.
