Alcohol as an unconditioned stimulus in human classical conditioning

Recent experiments with human subjects have shown that drug cues (e.g. sight of beer or needle and syringe) elicit different responses than do neutral stimuli. However, because conditioning has not been carried out in the majority of cases, it is not clear why drug cues have different response eliciting capacities; associative and nonassociative mechanisms may both play a part. In this experiment a counterbalanced differential conditioning procedure was used to isolate the role of associative processes in the development of physiological, behavioural, and subjective conditioned responses to cues for alcohol over the course of repeated conditioning sessions. Twelve healthy volunteers took part in the experiment which involved each subject attending for ten sessions. On physiological measures evidence was found for conditioning of skin conductance and cardiac inter-beat interval responses to cues for alcohol delivery. Over the course of conditioning on behavioural measures of drink consumption there were changes in the rate of consumption and number of sips taken as a function of whether or not the drinks contained alcohol. Finally, on subjective measures, there was a differential change in subjective state in response to alcohol and soft drink expectancy as conditioning progressed.