Study of Fearless Woman could Mean Improved PTSD Treatment
Understanding more about the area of the brain that produces fear could lead to better treatments for PTSD. Researchers studied a woman who is fearless, helping scientists pinpoint the amygdala, a small area of the brain, as being responsible for the emotion. The scientists say studying the woman's condition could lead to better treatments for post- traumatic stress disorder.
Case Study Shows Woman Doesn't Recognize or Experience Fear
The research article, published in the journal Current Biology, and conducted by University of Iowa scientists, presents a case of a woman who is the mother of three children who can't recognize fear in the facial expressions of others or experience it herself.
The researchers determined the reason is that the woman's amygdala is destroyed from a rare genetic neurologica disorder known as lipoid proteinosis that left holes in the small almond shaped structure in the brain.
Justin Feinstein, lead study author and a UI doctoral student studying clinical neuropsychology recorded the woman's response to spiders and snakes, horror films and haunted houses. He also obtained the woman's background history related to past traumatic events. They were able to pinpoint the lack of a functioning amygdala as the reason the woman is never frightened.
Daniel Tranel, Ph.D., UI professor of neurology and psychology and senior study author says the findings of where fear originates means drugs could be developed that target the amygdala to treat PTSD and other anxiety disorders.
"This past year, I've been treating veterans returning home from Iraq and Afghanistan who suffer from PTSD. Their lives are marred by fear, and they are oftentimes unable to even leave their home due to the ever-present feeling of danger," Feinstein said.
"In striking contrast, the patient in this study is immune to these states of fear and shows no symptoms of post-traumatic stress. The horrors of life are unable to penetrate her emotional core. In essence, traumatic events leave no emotional imprint on her brain."
Throughout the study, the researchers noted the woman had no day-to-day fears, including fear of dying. She was asked to record her emotions in a computerized diary. The scientists say the woman has experienced a number of traumatic events, some of which were life threatening, but never felt frightened.
Feinstein explains ...”the patient is able to experience other emotions, such as happiness and sadness..." He says the case study shows the brain is organized specifically to process fear in the region of the amygdala.
Oddly, the woman stated she was afraid of snakes and spiders, but in a store, she said she was overcome with curiosity, and began touching them - something, Antonio Damasio, professor of neuroscience at the University of Southern California who has been collaborating with Dr. Tranel suggests fear is processed unconsciously and instinctively.
The woman consciously knows she should avoid danger, but the scientists say without the amygdala that processes fear she has no alarm. Now that the scientists have verified where fear originates, they believe it could lead to improved treatment of PTSD and related anxiety disorders.