Fear factor function in brain

A look of fear on another person's face is recognizable instantly. The split-second ability of the amygdala, a small, almond-shaped structure deep in the brain, distinguishes fear in facial expressions. In particular, it relies heavily on visual information contained in the eye region.

A study by scientists at the University of Iowa, Iowa City, reports that the mechanism by which the amygdala contributes to processing visual information about facial expressions is by actively directing a person's gaze to the eye region to seek out and fixate on the critical visual cues for fear.

"People often think of the brain as passively receiving information from the senses about the world. Yet, there are mechanisms in the brain that allow us to actively seek out information in the environment in the first place," the study reports.

The research may have implications for conditions such as autism, where patients show abnormal fixation on facial features and have a disrupted ability to interpret emotion from facial expressions. "That the amygdala is critical for recognizing fear expressions has been evident from prior studies," admits Antonio Damasio, head of neurology at the Roy J. and Lucille A. Carver College of Medicine. "The new findings, however, suggest a specific mechanism for the impairments of fear recognition that can be found in patients with amygdala damage.

"This study tells us how it is that the amygdala plays a role in recognizing fear and, in doing so, it shows us that the amygdala isn't specialized just to detect fear in faces but really serves a more abstract and general role in seeking out potentially important and salient information in the environment."

COPYRIGHT 2005 Society for the Advancement of Education
COPYRIGHT 2005 Gale Group