Previously, most brain-imaging research focused on cognition rather than emotion. A new study uses functional magnetic imaging (fMRI) to examine emotional processing, finding that alcoholics have stunted abilities to perceive dangerous situations.
Results are published in the September issue of Alcoholism: Clinical & Experimental Research.
“We knew that alcoholics show a deficit in accurate recognition of facial emotions,” said Jasmin B. Salloum, research scientist at the National Institute on Alcohol Abuse and Alcoholism and corresponding author for the study. “This can lead to insensitivity to, and overestimation and/or misattribution of, certain facial expressions.”
“Relatives and friends of alcoholics often wonder why they continue to drink even though they intellectually know how detrimental this is for them,” added Andreas Heinz, director and chair of the department of psychiatry at Charité – University Medical Center Berlin. “Patients often relapse when entering previous drinking situations, that is, entering a bar or a shop in which you can buy alcoholic drinks. One reason may be that they fail to perceive dangerous situations. This study suggests that there is a neurobiological correlate of this often-reduced ability to perceive dangerous situations.”
Study participants comprised 11 male subjects who met DSM-IV criteria for alcohol dependence, as well as 11 healthy male subjects or “controls.” All participants were given a facial-emotion decoding task during which they were asked to determine the intensity level of a target emotion displayed via facial expressions of happy, sad, anger, disgust and fear. Researchers used fMRI to examine the subjects' brain-blood oxygenation level dependent (BOLD) responses (a BOLD signal will increase when that part of the brain is engaged in active processing of information).
Results showed that the greatest deficit among the alcohol-dependent individuals was in brain activation during decoding of negative emotional expressions, particularly in the affective division of the anterior cingulate cortex. The anterior cingulate is part of the prefrontal brain area.