Unconditioned response diminution in the skin resistance response.

An experiment was carried out to investigate unconditioned response diminution in the skin resistance response. By using an alternating series of paired and unpaired stimuli the differential predictions of the hypotheses of response interference, conditioned inhibition and expectancy could be tested. Ss were 27 young adult male students. The unconditioned stimulus was a tone of 105 db. For the conditioned stimulus the Ss were divided into two groups, one receiving a tone at 65 db and the other a tone at 85 db. Unconditioned response diminution was found. This diminution showed no significant change over trials and showed no correlation with amplitude of the conditioned response. This result is best explained in terms of expectancy.