No abstract

One experiment with rats explored whether an extinction-cue prevents the recovery of extinguished lever-pressing responses. Initially, rats were trained to perform one instrumental response (R1) for food in Context A, and a different instrumental response (R2) in Context B. Then, responses were extinguished each in the alternate context (R1 in Context B; R2 in Context A). For one group, extinction of both responses was conducted in the presence of an extinction-cue, whereas in a second group, the extinction-cue only accompanied extinction of R1. During a final test, we observed that returning the rats to the initial acquisition context renewed performance and that response recovery was attenuated in the presence of the cue that accompanied extinction of the response. The impact of the extinction-cue, however, was not transferred to the response that has been extinguished without the cue. Our results are consistent with the idea that extinction established an inhibitory cue-response association.

In two experiments with rats, we analyzed the effect of experiencing extinction in one task on the context specificity of a new association learned within a different task. Rats were trained to run in a runway for water in Task 1, and received taste aversion conditioning in Task 2 (the tasks were reversed in Exp. 2). Half of the rats received conditioning and extinction of Task 1 in Context A, whereas the other half received no extinction. Then all animals received training in the alternate task in Context B, prior to testing in Context C. When they were tested in Context C, Task 2 performance was attenuated if Task 1 had been extinguished prior to Task 2. These results are similar to those we have reported in humans, and consistent with the idea that extinction prompts attention to contexts, regardless of whether or not the contexts were involved in extinction.

No abstract

Two experiments explored whether forgetting of an association depended on previous extinction of a different association in rats. Experiment 1 found that when rats were conditioned and extinguished with flavor X, a subsequently acquired conditioned aversion to flavor Y was reduced by a 19-day retention interval, something that did not occur when X and the US were initially presented unpaired. Experiment 2 found that when rats received training and extinction in one of two tasks (conditioned aversion to sucrose in Experiment 2a, and running for water in a straight alley in Experiment 2b), subsequent learning of the alternative task was partially forgotten over the 19-day retention interval. These results are similar to those previously found when manipulating physical and conceptual contexts in rats and humans, respectively, and suggest that the passage of time may play a role similar to the one played by the change in physical or conceptual contexts on information retrieval.