Scientists using functional magnetic resonance imaging (fMRI) are exploring the possibility that low responders are less able to recognize certain modest sensory inputs because of atypical brain connectivity. Previous studies found that low responders are likely to require greater effort than high responders to identify facial emotions, a task that is key to social and emotional functioning. For the new study, researchers at the University of California San Diego showed pictures of happy, angry, and fearful faces to study participants undergoing brain scans. They examined connectivity between the amygdala, a structure involved in processing emotions and reward, and other brain regions, and whether differences between low and high responders were associated with problematic drinking later.
The study involved 108 college students aged 18–25. The students had taken an alcohol challenge and been identified as having either a low or high response to alcohol; none had developed an AUD before testing. They were organized into 54 pairs of low and high responders matched by sex, demographics, and substance use. Each participant underwent two fMRI sessions during which they observed pictures of faces, one after consuming alcohol, the other after a placebo beverage. The investigators measured the students’ accuracy at identifying facial expressions, compared amygdala activity, and used statistical analysis to look for associations between alcohol responses and problematic drinking five years later.