Human tolerance to alcohol: the role of Pavlovian conditioning processes.

To test the Pavlovian conditioning model of alcohol tolerance, two groups of eight male social drinkers each received five administrations of alcohol and five administrations of an equal volume of tonic each, on an alternating basis, during the initial 10-session tolerance development phase of the study. Group 1 received alcohol in a "distinct" environment and received tonic in a "home" environment. For group 2, the relationship between environmental cues and substances consumed was reversed. In a subsequent tolerance test session, both groups received alcohol in the distinct environment. When group 2 subjects were tested in this session under cues never before associated with alcohol, they were significantly more impaired on a complex cognitive task than group 1 subjects who expected alcohol; this result was in accord with the classical conditioning model of tolerance. In a final session, both groups received tonic in the distinct environment. As predicted, group 1 exhibited a compensatory enhancement in cognitive performance relative to group 2.