The amygdala is a region of the brain involved in creating the fear response. So here's a question that falls into the realm of weird science: If the amygdala gets damaged, might a person be incapable of experiencing fear? Oddly, the answer may be yes.
[The woman] has an unusual genetic disorder called Urbach-Wiethe disease. In late childhood, this disease destroyed both sides of her amygdala, which is composed of two structures the shape and size of almonds, one on each side of the brain. Because of this brain damage, the woman knows no fear, the researchers found.
According to the story, researchers were unable to frighten the woman. She experienced no fear of scary movies, snakes, spiders or even public speaking.