Being anxious once in a while may be good for you, according to a new study. A group of French scientists showed that the human brain allocates more processing power to circumstances when we detect social dangers.
Researchers from PSL Research University and the Université Pierre et Marie Curie wanted to explore the regions of the brain responsible for processing threatening sensory information and how it affects negative emotions. Though this is the first time scientists explored definite brain regions, they identified what is involved in this phenomenon.
The Sixth Sense
The study, published in the journal eLife, can now explain the "sixth sense" humans have that lets people identify an impending danger or stressful situation. In fact, the brain can detect social dangers or threats in these brain regions rapidly and automatically within 200 milliseconds.
Anxious people detect threats in a different brain region than individuals who are more relaxed. Though previous research shows that anxiety may cause oversensitivity to signals of threats, the difference on how people perceive threat may have a good purpose.
Rather than responding to threats only when needed, anxious people remain in a state of permanent uneasiness because of the fear of danger. The study found that being anxious allows the threats to reach the motor cortex of the brain more quickly, initiating a fight-or-flight response.
A Very Quick Look
The study involved 24 participants who were asked if a digitally altered face expressed anger or fear, but both are supposed to be perceived as threatening. The researchers, led by Marwa El Zein of the French Institute of Health and Medical Research, measured the electrical signals in the brains of the participants using an electroencephalogram (EEG) during the test.
Facial presentations of emotions can be unclear but the researchers were able to identify the thing that makes someone more threatening: gaze direction. They found that the direction a person was looking in affects the viewer's sensitivity to the other person's emotions. In the tests, anger that came with a straight stare at the viewer produced a reaction in the brain in only 200 milliseconds which is way faster than if the angry person is looking in another direction.
"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," said El Zein.
Survival Tactics
In terms of the regions of the brain affected, anxious people processed threats in the regions of the brain responsible for action (the motor cortex), while those who are less anxious processed the threats in their sensory circuits which are responsible for facial recognition (the temporal cortex).
If a person shows fear and looks in a definite direction, an anxious viewer may detect it more quickly than positive emotions and this may initiate quick reactions that can serve an adaptive purpose for survival. For instance, when we detect someone who seems to be afraid of something, an immediate, fight-or-flight mechanism is quickly triggered and we can immediately avoid danger. Being anxious can help us respond faster to threats.
"Efficient detection and reaction to negative signals in the environment is essential for survival. In social situations, these signals are often ambiguous and can imply different levels of threat for the observer, thereby making their recognition susceptible to contextual cues – such as gaze direction when judging facial displays of emotion," the researchers wrote in the study.
Photo: Patrik Nygren | Flickr
