Effects of real vs pretend shock on semantic differential judgments and the GSR in some classical conditioning paradigms

In two experiments subjects were shown different color 1-sec lights, one just before the end of a 4-sec UCS and the other coming 10 sec after UCS termination and 25 sec before the next UCS. For some groups the UCS was strong electric shock; for others it was a tone which subjects were instructed to imagine was a strong shock. The primary data were changes in semantic differential ratings of the lights before and after 12 “conditioning” trials. There were no differences among the groups. In a third experiment a 6-sec delay CS was used for GSR conditioning, some subjects receiving actual shock and others pretend shock. Only the former showed conditioning. The results are discussed in terms of a model of experimental demand.