Fear, PTSD, and the Brain

Taking a neuroscience perspective, the program centers on the brain circuits underlying fear, which seem to involve two separate pathways. Potential threat activates the amygdala, which automatically triggers sweaty palms and increased heart rate. A slower circuit runs through the cerebral cortex, which assesses the seriousness of the threat. Psychiatrist J. Douglas Bremner explains the need for balance between these two brain pathways. The automatic response is necessary to survive real threat, but the fear must not overwhelm one's capacity to think. Further research suggests that Vietnam veterans suffering PTSD have vivid recollections of the war, while more recent experiences are poorly recalled. An MRI scan of Dennis's brain reveals that the structure involved in memory is significantly smaller than normal. Constant terror seems to have changed the structure of his brain.