Contextual control of discriminated operant behavior

Abstract

Previous research has suggested that changing the context after instrumental (operant) conditioning can weaken the strength of the operant response. That result contrasts with the results of studies of Pavlovian conditioning, in which a context switch often does not affect the response elicited by a conditioned stimulus. To begin to make the methods more similar, Experiments 1-3 tested the effects of a context switch in rats on a discriminated operant response (R; lever pressing or chain pulling) that had been reinforced only in the presence of a 30-s discriminative stimulus (S; tone or light). As in Pavlovian conditioning, responses and reinforcers became confined to presentations of the S during training. However, in Experiment 1, after training in Context A, a switch to Context B caused a decrement in responding during S. In Experiment 2, a switch to Context B likewise decreased responding in S when Context B was equally familiar, equally associated with reinforcement, or equally associated with the training of a discriminated operant (a different R reinforced in a different S). However, there was no decrement if Context B had been associated with the same response that was trained in Context A (Experiments 2 and 3). The effectiveness of S transferred across contexts, whereas the strength of the response did not. Experiment 4 found that a continuously reinforced response was also disrupted by context change when the same response manipulandum was used in both training and testing. Overall, the results suggest that the context can have a robust general role in the control of operant behavior. Mechanisms of contextual control are discussed.

Figure 1

Results of Experiment 1. Mean elevation scores of the groups during acquisition in Context A (left) and testing in Context A or B (right; ± SEM).

Figure 2

Mean elevation scores of the groups during acquisition in Context A (top panel) and Context B (bottom panel) in Experiment 2.

Figure 3

Mean elevation scores of the groups’ R1 responding in S1 in Contexts A and B during testing in Experiment 2.

Figure 4

Mean elevation scores of the groups during acquisition in Context A (top panel) and Context B (bottom panel) in Experiment 3.

Figure 5

Mean elevation scores of the groups’ R1 responding in S1 in Contexts A and B during testing in Experiment 3.

Figure 6

Mean responses per minute for Group Same Manipulandum and Group Diff Manipulandum in Contexts A and B during acquisition in Experiment 4. The sessions were 30-min (1), 15-min (2), and 10-min (3–6) in duration.

Figure 7

Mean responses during the first two minutes of testing for Group Same and Diff in Contexts A and B in Experiment 4.

Figure 8

Mean latency to first response for Groups Same and Diff in Contexts A and B during testing in Experiment 4.

Figure 9

Four possible roles for the context in operant learning. Panel A. Direct association between the context and the response. Panel B. Direct association between the context and the response that is modulated by S. Panel C. Direct association between the context and the response that is then influenced by S via its possible S-R, S-(R-O), and S-O assocations. Panel D. Context as a modulator of the association between the response and the outcome which is then modulated by S via its possible S-R, S-(R-O), and S-O associations.