Abstract
BACKGROUND: There is considerable evidence that alcoholics differ from nonalcoholics in the processing of stimuli that have emotional content. The current study examines those differences that are present in multi-year abstinent individuals. METHODS: We compared reaction time (RT), accuracy, and Event Related Potentials (ERP) measures in long-term abstinent alcoholics (LTAA, n = 52) with that in age- and gender-comparable nonalcoholic controls (NAC, n = 47). Subjects were presented with male and female faces exhibiting happy, neutral, or sad facial expressions and were instructed to identify the picture gender in 1 task and the emotion being expressed in a subsequent task. RESULTS: LTAA had slower RTs than NAC when instructed to identify emotion, while RT was comparable when identifying gender. There were no differences between groups on task accuracy. P160 latency was increased in LTAA for both tasks compared to NAC, though P160 amplitude did not differ between groups. The P160 effect was about 5 x as large as the RT effect and was statistically independent of the RT effect, while the RT effect was no longer present after removing variance because of the P160 effect. CONCLUSIONS: Our data demonstrate slower early processing of emotional facial stimuli in alcoholics that is unresolved by long-term abstinence and is most sensitively indexed by delayed P160 latency in LTAA.