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.