The No-Fear Woman (And What Her Brain Reveals)
Scientists study the brain and behavior of a woman known as "SM" who laughs when most people tremble.

A woman who feels no fear is teaching scientists about the connections between our brains and our behaviors, and offering hope for people whose lives are destroyed by trauma.

In a new study, researchers exposed the unusual woman -- well known to science as SM -- to as many scary situations they could come up with. From an infamously fright-filled haunted house to the spider section of a pet store, SM, who completely lacks a brain structure called the amygdala, failed to show any signs of being afraid.

Instead, she held a snake, pet its scales and touched its tongue. She enjoyed intensely scary horror movies like they were thrilling but fun roller coaster rides. And she revealed through her stories and her diary a lifetime of behaviors that would strike most people as odd and qualify, by all standards, as dangerous.

From 2010. Read the rest here.