August 13, 2009
Excessive Drinking Impacts Facial Expressions
Excessive, chronic drinking can cause brain damage leading to the development of emotional abnormalities that can interfere with healthy interpersonal relationships.
Alcoholism-related emotional abnormalities can be subtle, such as misperceiving facial and verbal cues, or obvious, such as emotional flatness and apathy or sudden outbursts of anger. "Alcoholics also have problems in judging the emotional expressions on people's faces," Ksenija Marinkovic, assistant professor in residence in the radiology department at the University of California, San Diego is quoted as saying. "This can result in miscommunication during emotionally charged situations and lead to unnecessary conflicts and difficulties in interpersonal relationships. The resulting negative repercussions can, in turn, contribute to increased drinking."
For this study, researchers used functional magnetic resonance imaging (fMRI) technology to examine two groups of men matched on socioeconomic backgrounds, age, education, and IQ. Fifteen were abstinent long-term alcoholics and 15 were healthy, nonalcoholic controls. Findings suggest that diminished activity of the amygdala and hippocampus regions of the brain underlie emotional impairments observed in abstinent long-term alcoholics.
"Whereas nonalcoholic adult men showed stronger activation in the amygdala and hippocampus when viewing faces with emotional expressions," said Marinkovic, "the alcoholics showed decreased activation in these brain areas, and furthermore responded in an undifferentiated manner to all facial expressions. The alcoholics also were impaired on the intelligence-appraisal task, possibly due to their dampened amygdala activity."
"In addition," Edith V. Sullivan, professor in the department of psychiatry and behavioral sciences at Stanford University School of Medicine, was quoted as saying, "unlike the controls, the alcoholics recruited the prefrontal cortex while processing facial emotions, perhaps compensating for dampened activation of neural centers, such as the amygdala and hippocampus, which are normally invoked for such processing."
Use of a different neural "route" to process the same facial emotional information presented to controls is consistent with other fMRI studies, Sullivan added, which have demonstrated that alcoholics need to invoke additional and sometimes higher-order brain systems to accomplish a relatively simple task at normal levels.
"Whether the differences between controls and alcoholics in brain activation existed before the onset of alcoholism," said Sullivan, "or are the result of neural circuitry changes or differences in blood perfusion caused by chronic alcohol consumption, intoxication or withdrawal, remain as questions to be answered."
SOURCE: Alcoholism: Clinical & Experimental Research, November 2009