Alcohol Stops Brain from Interpreting Social Cues

Alcoholics fail to communicate with people because their brains don't interpret social cues, a new study has found. Researchers said that long-term alcohol exposure can break communication between two areas of the brain that work together to interpret social signals.

The study was conducted by researchers at the University of Illinois at Chicago College of Medicine who found that alcohol inhibits signalling between amygdala and pre-frontal cortex.

The pre-frontal cortex is a region associated with cognitive function, social behavior, decision making and modulation of intense behavior.

Previous research too has shown that alcohol suppresses activity in amygdala- a part of the brain associated with processing social signals. Having a large amygdala has been linked with good social communication and larger circle of friends.

"Because emotional processing involves both the amygdala and areas of the brain located in the prefrontal cortex responsible for cognition and modulation of behavior, we wanted to see if there were any alterations in the functional connectivity or communication between these two brain regions that might underlie alcohol's effects," said K. Luan Phan, UIC professor of psychiatry.

The study was based on a small group of 12 participants who had a history of heavy social drinking. Researchers hooked the people on brain scanners while they were shown pictures of different facial expressions. The participants were also given drinks that either contained a placebo or alcohol while they looked at the pictures.

The photographs used in the study were of happy, sad or angry people. Each participant was shown three pictures on the screen- one picture on top and two at the bottom. Participants had to pick the picture from the bottom row that was similar to the one on top.

Researchers found that people on alcohol had reduced levels of activity between anygdala and the orbitofrontal cortex, which is associated with social cues and decision-making.

Alcohol also reduced brain's reaction to threat, the team found.

"The amygdala and the prefrontal cortex have a dynamic, interactive relationship. How the amygdala and prefrontal cortex interact enables us to accurately appraise our environment and modulate our reactions to it," Phan said in a news release. "If these two areas are uncoupled, as they are during acute alcohol intoxication, then our ability to assess and appropriately respond to the non-verbal message conveyed on the faces of others may be impaired. This research gives us a much better idea of what is going on in the brain that leads to some of the maladaptive behaviors we see in alcohol intoxication including social disinhibition, aggression and social withdrawal."

The study is published in the journal Psychopharmacology.