When she was ten, anonymous test subject SM damaged her amygdala. Now, not only does SM have two symmetrical black holes where her amygdala should be, but she also experiences life without fear. Although the amygdala is known to play a role in producing fear and anxiety, some scientists now believe that the amygdala is solely responsible for fear production. In a new study published in Current Biology, lead researchers, along with graduate student Justin Feinstein of the University of Iowa in Iowa City, tested whether SM could experience fear. The researchers took SM to a pet store filled with snakes and spiders, showed her scenes from horror films, took her to a haunted house, and measured her reaction to other’s fear. In each case they found that SM seemed excited and inquisitive, but lacked any fearful response. SM was also required to keep an electronic diary rating daily 50 different emotional states from 1 to 10, where “fearless” received the highest average rating. This same fearlessness is consistent with SM’s past as well. While researchers hope that their findings will lead to new therapies for post-traumatic stress disorder, or new forms of psychotherapy, critics state that more case studies are needed before the results could be considered definitive.