Abstract
In two experiments an S delta was established which signalled the absence of an instrumental contingency between a particular response, R1, and a particular reinforcer, Rf1. The S delta suppressed operant responding, and the specificity of this suppression to the elements of the response-reinforcer association, R1 and Rf1, was explored. Experiment 1 showed that the S delta suppressed performance of R1 more effectively than it suppressed performance of a second response, R2. Experiment 2 showed that the S delta suppressed performance of a response rewarded with Rf1 more effectively than it suppressed performance of a response that had been rewarded with a second reinforcer, Rf2. These results suggest that an S delta's suppressive effects are specific to the particular response and reinforcer, which were uncorrelated in its presence during training. The implications of these results for theories of inhibitory discriminative control and for theories of occasion setting are discussed.