Rape survivor Erika Krouse rarely dreams. She has lost memories. She has trouble remembering what happened the prior week but knows in spectacular detail how it felt to be raped when she was a child by someone her mother loved. A heartbreaking passage in her memoir Tell Me Everything: The Story of a Private Investigation explains, "It's as if the regular roads are missing from my mental map."

Trauma can change the brain in various ways. Brain chemistry as well as structure may be altered, affecting cognition, emotional management and neurological functioning. Specific areas of the brain that can be negatively affected by trauma include the amygdala, hippocampus and prefrontal cortex.

The amygdala is an almond-shaped section of the brain that assists in emotional management, including fear response and survival instincts. If a person with post-traumatic stress disorder (PTSD) is exposed to stimuli that recalls a traumatic episode, the amygdala can become hyperactive, and this ...