Do you ever wonder why that drunk guy continued to trash-talk some muscle-bound guy in a bro tank at the bar, when he clearly should have been running away? I mean, didn’t Drunk Guy notice that Bro Tank looked really angry, that he kept getting angrier and angrier?
In reality, Drunk Guy’s brain might not have been able to tell just how angry Bro Tank was, due to alcohol-induced disruptions in his drunk brain.
New research from the University of Illinois, Chicago, suggests that acute alcohol consumption affects the ability of the brain to process simple social cues, like the important facial expressions such as anger or fear. In an experiment involved 10 college-age men and 2 college-age women who reported an average of 7.8 age “binge drinking episodes per month,” researchers found that under the influence of alcohol, the participants could not identify faces that were fearful or angry.
Half the participants received a 16% alcoholic beverage (this is just a tad stronger than wine) and half received a placebo. In an fMRI machine, the participants were shown a target face, either happy, fearful, angry, or neutral, and had to match it to one of two faces shown below the target face.
Researchers found that under the influence of alcohol, neural pathways between the amygdala and important parts of the prefrontal cortex were interrupted. The amygdala, responsible for processing emotions, is an almond shaped bundled of neurons deep within the brain. The prefrontal cortex is extremely important for social and emotional processing and decision making.
From UIC Professor of psychiatry, K. Luan Phan (via Newswise):
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 alcohol also disrupted the important amygdala function of detecting a dangerous situation, which could explain why Drunk Guy had no idea he was about to get punched by Bro Tank.