Alcohol-induced impairment of behavioral control: Effects on the alteration and suppression of prepotent responses

Objective: Alcohol use in humans is associated with aggression and other socially inappropriate behaviors. These adverse effects have been attributed to an acute impairment of behavioral control, and research findings indicate that inhibitory aspects of behavioral control might be particularly vulnerable to the effects of alcohol. The present study tested the degree to which alcohol-induced impairment of behavioral control is due to a specific impairment of inhibitory mechanisms or due to a general information processing deficit. Method: Forty subjects (29 men) per-formed a cued reaction time task before and after receiving 0.65 g/kg alcohol or a placebo. Subjects performed the task under conditions that differed in the type of response needed to maintain behavioral control: response-suppression and response-alteration. Results: Alcohol impairment was observed when behavioral control was dependent on response-suppression, but no impairment was observed when control relied on response-alteration. Conclusions: The findings point to the susceptibility of inhibitory processes by showing that alcohol can be particularly detrimental to behavioral control in situations where prepotent responses must be completely suppressed. Evidence for alcohol-induced impairment of inhibitory functions could provide important clues about basic behavioral mechanisms, by which alcohol disrupts such higher order cognitive processes as working memory, learning and decision making.