Learning to inhibit the response during instrumental (operant) extinction

Abstract

Five experiments tested implications of the idea that instrumental (operant) extinction involves learning to inhibit the learned response. All experiments used a discriminated operant procedure in which rats were reinforced for lever pressing or chain pulling in the presence of a discriminative stimulus (S), but not in its absence. In Experiment 1, extinction of the response (R) in the presence of S weakened responding in S, but equivalent nonreinforced exposure to S (without the opportunity to make R) did not. Experiment 2 replicated that result and found that extinction of R had no effect on a different R that had also been reinforced in the stimulus. In Experiments 3 and 4, rats first learned to perform several different stimulus and response combinations (S1R1, S2R1, S3R2, and S4R2). Extinction of a response in one stimulus (i.e., S1R1) transferred and weakened the same response, but not a different response, when it was tested in another stimulus (i.e., S2R1 but not S3R2). In Experiment 5, extinction still transferred between S1 and S2 when the stimuli set the occasion for R's association with different types of food pellets. The results confirm the importance of response inhibition in instrumental extinction: Nonreinforcement of the response in S causes the most effective suppression of responding, and response suppression is specific to the response but transfers and influences performance of the same response when it is occasioned by other stimuli. Theoretical and practical implications are discussed. (PsycINFO Database Record

Figure 1

Designs of Experiments 1 – 5. + signifies reinforced trials; - signifies extinction trials. See text for more explanation.

Figure 2

Mean number of responses (+ SEM) during the S and pre-S periods during acquisition (Panel A), extinction for Group SR (Panel B), and test (Panel C) in Experiment 1.

Figure 3

Mean number of responses (± SEM) during the S and pre-S periods during SR1 acquisition (Panel A), SR2 acquisition (Panel B), and extinction for Group SR1 (Panel C) in Experiment 2.

Figure 4

Mean number of responses (± SEM) during the S and pre-S periods during the SR1 and SR2 tests of Experiment 2.

Figure 5

Mean number of responses (± SEM) during the S and pre-S periods during acquisition in Experiment 3. Acquisition for the four stimulus/response combinations are shown separately: S1R1 in Panel A, S2R1 in Panel B, S3R2 in Panel C, and S4R2 in Panel D.

Figure 6

Mean number of responses (± SEM) during the S and pre-S periods during the extinction treatment given Group S1R1 in Experiment 3.

Figure 7

Mean number of responses (± SEM) during the S and pre-S periods for each group during the transfer test sessions of Experiment 3.

Figure 8

Mean number of responses (± SEM) during the S and pre-S periods for each group during the transfer test sessions of Experiment 3.

Figure 9

Mean number of responses (+ SEM) during the S and pre-S periods during S1R acquisition (Panel A), S2R acquisition (Panel B), and extinction for Group S1R (Panel C) in Experiment 5.

Figure 10

Mean number of responses (± SEM) during the S and pre-S periods for each group during the test sessions of Experiment 5. Responding in S1 and S2 is shown separately.