When the brain has nothing to fear

‘Last year I was the treatment of veterans returning from Iraq and Afghanistan with PTSD,’ he said. ‘Their lives are marked by fear, and are often unable to leave their homes in part because of the widespread sense of danger. In sharp contrast, SM is immune to these states of fear and shows no signs of trauma. In essence, the traumatic events leave no mark on the emotional brain of MS. Through the understanding of how the brain processes fear through cases like SM, we may one day be able to create treatments that selectively target the brain areas that allow fear to take on our livesFeinstein said that the average person can have different definitions of fear, but its goal is ultimately to identify emotions such as fear, on the basis of biological machinery that triggers them.

A new study, published online in the journal Current Biology, a Cell Press publication, provides a new vision of the emotional life of a unique individual who completely lacks the function of an almond-shaped brain structure called the amygdala. Studies over the past 50 years have shown that the amygdala plays a central role in generating fear reactions in animals from rats to monkeys. Based on detailed case study of a woman identified only as SM, it now appears that the same is true for humans.

‘Normally, the amygdala is constantly sorting all the information coming into our brain through the different senses in order to quickly identify anything that could impact our survival,’ he said. ‘Once it detects a threat, the amygdala and full orchestra, a rapid response of the body that forces us to stay away from the threat, which improves our chances of survival.’

Dr. Lehrer said this emphasizes the benefits of potentially high childhood and adolescent health interventions that have not yet been identified. We focus on the relationship between health and education because they clarify the mechanisms linking the two have important implications for a political project.

‘The nature of fear is survival and the amygdala helps us to stay alive to avoid situations, people or objects that put our lives in danger,’ said Justin Feinstein of the University of Iowa. ‘Because MS is missing the amygdala, it lacks the ability to detect and avoid danger in the world. It is remarkable that she is still alive.’

The conclusion provides a powerful grip on the connection between brain and behavior, particularly in the context of situations that normally cause fear, researchers say.

To explore the role of, amygdala Feinstein and his team at the University of Iowa, observed and recorded the responses of MS in a variety of situations that make most people feel fear. They also had her fill out questionnaires probing different aspects of fear, the fear of death to fear of public speaking. In addition, SM faithfully recorded his emotions at different times of the day, while carrying around a PDA for a period of 3 months.

In all, the questionnaire measures and scenarios, MS do not be afraid.