Compensating for alcohol-induced impairment: alcohol expectancies and behavioral disinhibition.

OBJECTIVE Studies have shown that expectations of alcohol-induced impairment can produce adaptive responses to alcohol that serve to reduce the degree of behavioral impairment displayed. The present research examined how an expectancy-induced adaptive response could reduce the impairing effects of alcohol on response activation, while at the same time increase its impairing effect on response inhibition. METHOD Social drinkers (N = 48) practiced a stop-signal choice reaction time (RT) task that measured their speed of responding and their ability to inhibit responses to stop signals. Subjects then received 0.65 g/kg of alcohol, a placebo beverage, or no beverage. Prior to performing the task again, one-half of the sample was given information to expect that alcohol would slow (i.e., impair) their RT. The others received no expectancy treatment. RESULTS Subjects led to expect slowed RT displayed faster RTs but fewer inhibitions under alcohol, compared with those who received no such expectancy The same pattern of results was observed under the placebo condition. In the "no beverage" condition, the expectancy treatment had no significant effect on subjects' RT or inhibitions. CONCLUSIONS The findings demonstrate that an alcohol expectancy can reduce impairment of one aspect of performance under the drug while increasing its impairing effect on another. The study contributes to a growing body of research that highlights the importance of understanding interactions between the expected and pharmacological effects of alcohol.