Drug-free behavioral history affects social drinkers' tolerance to a challenge dose of alcohol

This research tested the hypotheses that behavioral tolerance to a challenge dose of alcohol is enhanced by prior drug-free training under environmentally induced impairment and that the addition of verbal feedback about performance during training is ineffective.

A total of 44 male social drinkers participated in two studies that provided drug-free training of a psychomotor task (tracometer) under conditions of either moderate or intense environmental impairment. Impairment was produced and manipulated by the position of a screen that reduced the visibility of the task target display. Subjects were assigned to one of four groups in each study. Two experimental (E) groups received drug-free training under impairment, either with or without feedback, and two control (C) groups were trained either with or without feedback. After drug-free training, all subjects received a .62 g/kg dose of alcohol and performed the task.

E groups displayed more resistance to the effect of alcohol than did C groups, and feedback had no significant effect. Training under moderate or intense environmental impairment diminished drug effects to such an extent that subjects' performance under alcohol did not differ from their drug-free baselines.

Results show that a drug-free history of performance under environmental impairment can increase behavioral tolerance to a challenge dose of alcohol. The findings imply that an individual's drug-free behavioral history may contribute to differences in response to a challenge dose of alcohol.