Alcohol and the ability to inhibit behavior in men and women.

OBJECTIVE This experiment tested the impairing effect of alcohol on cognitive inhibitory control of behavior in the absence of any motivational consequences for exhibiting or inhibiting a response. METHOD Men (n = 24) and women (n = 24) were trained on a computerized "go-stop" task that measured response reaction time (RT) to a go signal and inhibitory control by the number of inhibitions to a randomly occurring stop signal. Equal numbers of men (n = 8) and women (n = 8) were assigned to one of three groups (n = 16), and they performed the task alone in a room under either alcohol (A), placebo (P) or no-treatment control (C) conditions. Blood alcohol concentrations of men and women were matched in Group A by administering 0.62 and 0.54 g/kg of alcohol, respectively. RESULTS Alcohol impaired inhibitory control and had no significant effect on response RT. Under P and C conditions, no changes in inhibitions or response RT were observed. In addition, no significant gender effects were found. CONCLUSIONS The results showed that inhibitory control of behavior was impaired by a moderate dose of alcohol that did not affect response RT.