Effect of Stress on Spontaneous Recovery of a Pavlovian Conditioned Response
Siegl, Erica M.
Exposure to uncontrollable shock creates emotional, behavioral, and cognitive deficits in animals. One cognitive repercussion is learned helplessness--the subsequent inability to form simple R-S associations. Originally demonstrated with operant conditioning, studies using Pavlovian conditioning returned various and conflicting results. In a degraded contingency stress appears to facilitate learning, while interfering with discrimination tasks in a feature negative paradigm. To account for these results, Bouton proposed a context specific model of inhibition, emphasizing the dependence of response of context. Using this theory, we hypothesized that stress interferes with the formation of inhibitory associations. The purpose of this study was to investigate whether rats exposed to uncontrollable shock prior to extinction procedures will show evidence of attenuated inhibitory conditioning, as measured by strength of CR during the spontaneous recovery test, in comparison to rats not exposed to uncontrollable shock. Contrary to expectations, there was no evidence of spontaneous recovery in either the stressed or control group of rats. Over-training of extinction or the unstable nature of appetitive conditioned responses may explain this result. Future studies should consider minimizing extinction training.
vi, 17 p.
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