Psychophysiological effects of alcohol-related stimuli: I. The role of stimulus intensity.

The present study extends previous research on conditioning factors in the physiological and subjective responses to naturalistic alcohol-related stimuli. Specifically, the effects of differential alcohol ingestion histories and of stimulus intensity were examined on the occurrence of conditioned responses in the laboratory. Twelve alcoholic subjects and twelve moderate drinkers participated in a single experimental session consisting of randomized presentations of three types of stimulus trials. Each trial included gustatory and visual presentation of alcohol, pepper juice (as a control for stimulus intensity) or water. Both alcohol and pepper juice stimuli significantly increased heart rate and skin conductance responses as compared with water stimuli. In contrast, subjects significantly increased self-report ratings of high and feel different following alcohol stimuli only. Physiological and subjective responses were similar in alcoholics and social drinkers with the exception of significantly higher self-reported craving in alcoholic subjects. These findings suggest that stimulus intensity contributes to the magnitude of physiological but not subjective responses to alcohol-related stimuli.