A new study shows that anxiety makes people more sensitive to social threats, giving them some kind of "sixth sense" that helps protect them from danger. Anxious people also reportedly process threat detection from a different part of the brain compared to those who are not anxious.

Researchers led by Marwa El Zein from the French Institute of Health and Medical Research (INSERM) and the Ecole Normale Supérieurein Paris recruited 24 volunteers and showed them digitally altered faces. Some of the faces had the same expression, but the eyes were looking at different directions.

The study participants were asked to identify if the faces showed fear or anger. The study involved 1,080 trials.

The researchers found that in people with non-clinical anxiety, the brain shifts the processing of threats from the sensory circuits to the motor circuits. Sensory circuits are involved in facial recognition, while motor circuits are involved in producing action.

They also found that the brain recognizes threat from someone not just based on his or her display of emotion, but also on the direction of his or her gaze. For example, when someone with an angry face looks directly at you, your brain will respond to the threat in just 200 milliseconds, a rate faster than when the angry person is looking somewhere else.

"In contrast to previous work, our findings demonstrate that the brain devotes more processing resources to negative emotions that signal threat, rather than to any display of negative emotion," El Zein said in a press release. "In a crowd, you will be most sensitive to an angry face looking towards you, and will be less alert to an angry person looking somewhere else."

The study was published online in the Dec. 29. issue of the journal eLife.