Prior exposures to the laboratory enhance the effect of alcohol

We compared responses to 0.6 g/kg alcohol of normal male drinkers in a laboratory environment that was new to the subjects with the responses of a second group in the same environment who had two prior exposures to the laboratory environment and procedures. Alcohol-induced increases in heart rate, cheek temperature and self-reported intoxication were greater in the subjects who had previous exposure to the laboratory environment than in the subjects who had no such previous exposure. Differences in blood alcohol concentration (BAC) also were found between the two environments. However, differences in the physiological and self-report measures were found after matching subjects in terms of BAC. These results suggest that novelty effects may contaminate alcohol responses in novel laboratory environments, and they add to our understanding of nonpharmacological factors in the responses to drugs.