Keep your hands off my Amygdala!

Humans, Like Animals, Are Fearless Without Amygdala

By SINDYA N. BHANOO, Published: December 16, 2010

In the 1930s, researchers discovered that when a certain part of monkeys’ brains was removed, the animals became fearless. They approached snakes, started batting them around like sticks and played with their hissing tongues.

This experiment has been repeated in animals numerous times, and the scientific consensus is that when the amygdala is removed, an animal loses any sense of fear.

Now, scientists have confirmed that a missing amygdala results in similar behavior in humans, according to a study in the journal Current Biology.

“There’s not very many humans with this sort of brain damage,” said Justin Feinstein, the study’s lead author and a clinical neuropsychologist at the University of Iowa. “Luckily for us, we had access to a patient, SM, and we studied her different fear behaviors and we read her personal diaries.”

Patient SM, because of a rare condition called lipoid proteinosis, has holes where her amygdala would normally reside. Researchers found that she, like the monkeys, has no fear of creatures like snakes and spiders, which ordinarily alarm most people.

But while this behavior is relatively benign, the researchers also found that SM put her life at risk. In one instance, she walked through a park alone at night and was attacked by a man with a knife.

“The following day, she again walked through the same park,” Mr. Feinstein said.

Advertisements

About carlos

I'm a curious person, of reasonable intellect, "on the beach" (retired) and enjoying my interest in anthropology, language, civil rights, and a few other areas. I've been a hippie/student/aerospace tech writer in the '60s, a witness to the Portuguese revolution in the ‘70s, a defense test engineer and witness to the Guatemalan genocide in the '80s, and a network engineer for an ISP in the '90s. Now I’m a student and commentator until my time is up. I've spent time under the spell of the Mesoamerican pyramids and the sweet sound of the Portuguese language. I've lived in Europe, traveled in Brazil, Central America, Iceland, New Zealand, and other places. My preferred mode of travel is with a backpack and I eat (almost) anything local. Somehow, many of the countries I have been to have had civil unrest (for which I was not responsible). I'm open to correspond with anyone who might share my liberal, humanist interests. I live in San Buenaventura, California.
This entry was posted in Anthropology and tagged , , . Bookmark the permalink.