A woman who can not feel "terror" due to damage of the amygdala

Brain'sTemporal lobeA collection of almond-shaped neurons inside the inner part "Amygdala(I am sorry)". When this amygdala body does not function, it seems that there is a possibility that human beings can not feel the fear, and they will be taking actions that are dangerous.

The relationship between the amygdala and "fear" has been suggested by experiments already using animals so far, but also that human beings do not feel fear if they damage the amygdala,University of IowaIt was demonstrated for the first time by research of.

Details are as below.Brain Anomaly Leaves Woman Without Fear

No Fear Felt By Woman Without Functioning Amygdala

Mr. Justin Feinstein, clinical neuropsychologist at the University of Iowa,Urbach-Wiethe diseaseLocal bilateral amygdala lesions (focal bilateral amygdala lesions) appeared as a very rare genetic disease condition called "Ulbach-Wiede type lipid proteinosis", and a 44-year old female SM who does not function the amygdala looks at snakes and spiders · Seeing horror movies · Visiting a haunted house · Reflecting on past traumatic experiences, etc. If you are a normal person, you experience various situations that fear you fear and recorded the reaction.

In addition to having answered various standardized questions to measure various fears such as "fear of death" and "fear of talking in front of the public", they also randomly "daytime" during the three months The current fear level "with a device to listen to" emotional diary "attached. Thesis isCurrent BiologyIt is published in the magazine.

Throughout the experiment SM did not show a feeling of "fear" at all, but in spite of having said that "I do not like spiders and snakes always, I always try to avoid," even though I talked about snakes and spiders as soon as I visited the pet shop It began to touch and surprised the researchers. When asked why he touched disgusting creatures, he replied "I could not overcome curiosity". S. M. who is the mother of three children is witnessed by the children as they approach the house without getting afraid if they see a big snake near their home.


Mr. SM who has a very specific disease condition has cooperated with the research of various scientists over the past two decades but that SM can not recognize the expression of "fear" from the human face Although it was clarified so far, this time it is the first time that Mr. SM himself has been shown through systematic experiments that he can not feel fear himself. Also, in experiments using monkeys and rodents, relationships of amygdala and fear have been suggested so far, but this is the first time that this was demonstrated in humans.

SM said that feelings other than fears such as "happiness" and "sorrow" can be felt in the same way as people who do not have brain damage, which means that certain parts of the human brain have specific emotions It seems to suggest that it is supposed to serve.

Position of the amygdala in the human brain.


The amygdala that is in charge of fear does not function SM's has not experienced fear at that time despite experiencing such events that life is endangered many times in my life so far, Because there is no,PTSD (Posttraumatic Stress Disorder)It seems that it will never become.

Dr. Daniel Tranel, one of the authors, said the results are PTSD andAnxiety disorder"It is suggested that PTSD occurs in a specific part of the brain.Psychotherapy and medication therapy currently used as a treatment method for PTSD are targeted to the amygdala body We may be able to improve the accuracy of treatment so that it reaches pinpoint as it is, "he said.

Currently it is said that there are 77 million PTSD patients in the U.S. It is estimated that 300,000 of the soldiers returning from Iraq and Afghanistan will suffer from PTSD.


Justin Feinstein stated that PTSD treatment targeting the amygdala is not to resect or alter the amygdala by surgery, saying that he has been treating PTSD of returned soldiers from Iraq and Afghanistan during the past year.

Long-term exposure therapy "that the patient repeats the behavior that feels horror seems to be able to weaken the response of the amygdala to its terrible situation. "This long-term exposure therapy is a repeated therapy for patients who are most afraid of suffering, and there is no intention to modify this part by surgery at all," Feinstein says.

Some PTSD patients who treat Feinstein may even say that life has been ruined by fear, not being able to leave the house because of the constant danger of feeling. On the other hand, SM, who can not feel the fear, is not suffering from PTSD despite having experienced many occasions that would become a trauma for ordinary people, but SM's experience Many of the events seem to endanger the lives because they can not feel fear at all.

As an example of the dangers SM encountered to not feel fear one moment when SM approached a suspicious man apparently under the influence of drugs when he was 30 years old, he was stuck with a knife " I will kill you "is said to have been threatened. Mr. SM who had never felt any fear then heard that the choir was singing in a nearby church and said, "If you kill me, angels are not silent," the men are going to smile Ms. SM was released and left.


"Because the amygdala does not function, she is going to expose herself to the risk of being avoided by those who are not damaged in the brain, trusting anything that does not feel fear, what But at this time, the man with the knife may have escaped his life because he felt ecstatic about her strange behavior which does not feel terror, "Feinstein said Says.

"People who do not feel any fear" are likely to associate like "unbeatable human weapons", but if there were soldiers who could not really feel fear, the crisis could not be avoided It might be a low-viable soldier. Fear is one of the most important emotions for human beings to avoid danger and protect lives. It is not exaggeration to say that mankind has survived so far because of this feeling.