Absence of Fear

A woman with no fear- Where Does Fear Come From? (Hint: It's Not the Creepy Basement) 
by Meredith Melnick

CLAIM--

"Because of a degenerative condition that left her with damage in certain brain structures, researchers say, SM is incapable of feeling fear."

1. "...because they spent several days trying to scare her silly. They exposed SM to snakes and spiders at a   pet store, showed her clips of horror movies like The Shining and The Blair Witch Project, and took her through a haunted house in a former sanatorium."

2. "SM says that she hasn't felt afraid since a childhood incident involving a snarling Doberman pinscher."

3. "The authors note that SM's response to what would normally be considered fear-inducing situations was not characterized simply by a lack of responsiveness, but rather a heightened arousal and interest."  

• SM is not able to respond or show emotion because there is something wrong with her amygdala
• the amygdala is the part of the brain that stores emotions and some past memories
• with the amygdala not acting correctly would cause someone not able to connect certain emotions to a situation, the person would come off as emotionless

here is a description of a situation that she was in-

A man jumped up from a park bench, pressed a knife to her throat and hissed, "I'm going to cut you."
SM, who heard a church choir practicing in the distance, looked coolly at him and replied, "If you're going to kill me, you're going to have to go through my God's angels first."
The man suddenly let her go. She didn't run home. She walked.
"Her lack of fear may have freaked the guy out," Feinstein said.
But it also got her into that situation in the first place, he noted. SM had willingly approached the man when he asked her to, even though it was late at night and she was alone, and even though she thought he looked "drugged out."

 

sentence of CONCESSION--

"To the average observer, it would seem that 44-year-old patient "SM" was just another typical mother of three: she scores normally on IQ tests, has good language skills and a decent memory."

I do agree that a corrupt amygdala would cause someone not able to show emotions because that is the part of the brain that houses emotions. If someone is not able to realize what emotions they are feeling then they  are not going to be able to connect those emotions to a situation.