The effect of drink familiarity on tolerance to alcohol.

Cues associated with familiar alcoholic drinks such as beer may, through repeated association with the unconditioned stimulus properties of alcohol, acquire the status of classically conditioned stimuli. It has been proposed that such drug-related conditioned stimuli mediate drug tolerance. Thus, the aim of the present experiment was to test this proposition on cognitive, subjective, and psychophysiological indicators of alcohol tolerance using human subjects. Two groups of subjects received alcohol in the form of a familiar drink (beer) or an unfamiliar drink (blue peppermint mixture). Both drinks contained the same dose of alcohol and were consumed at the same rate. Although conditioned heart rate and skin conductance responses occurring while subjects looked at and tasted the test drinks were weak, there were strong indicators of conditioned tolerance on the performance measures following consumption. Subjects who consumed the unfamiliar drink were significantly poorer on cognitive and motor tasks, and they rated themselves more intoxicated than did those who consumed the familiar drink.