Alcohol, intentional control, and inappropriate behavior: regulation by caffeine or an incentive.

This study shows that reduced intentional control under alcohol can be counteracted by caffeine or an environmental incentive. Four groups of social drinkers (n = 11) received 1 of the following: 0.62 g/kg alcohol (A), alcohol with 4.4 mg/kg caffeine (AC), alcohol with a rewarding monetary incentive (AR), or a placebo (P). They then performed a word stem completion task that provided separate measures of the influence of controlled and automatic processes governing responses. Controlled processes were depressed in Group A compared with Group P, whereas Groups AR and AC did not differ from Group P. Most inappropriate responses were displayed under alcohol alone, fewer with caffeine, and least with incentive. No treatment significantly affected automatic processes.