The hypothesis was tested that the pattern of CR magnitudes developed after long training in GSR discrimination conditioning will remain the same despite a change in the sequential positions of the individual CSs following a stereotyped order of presentation. The role of instructional parameters and levels of awareness of the CS-US sequence during the course of discrimination conditioning was also investigated.
Two experimental groups and two control groups; each consisting of six undergraduate Ss (three males, three females), were tested. Using a five-second CS-US interval, two responses were observed: a first response during the delay, and a second response following CS termination (with. US omitted). Ss informed of the OS-US sequence showed superior discrimination performance for both responses. Informed Ss appeared to be able to inhibit first response to the disparity CS, but were unable to inhibit the second response, indicating that second response discrimination represents a more basic process in classical conditioning than first response discrimination, since the former may be unaffected by verbal-perceptual control. Although no CR pattern invariant to the sequential presentations of CSs was observed, several improvements in the experimental procedure for future research were suggested. The importance of investigation in this field was stressed.