On the differences in degree of renewal produced by the differentrenewal designs

Abstract

tThis paper addresses sources contributing to the differences in the degree of recovery from extinctionobserved with different renewal paradigms. In two lick suppression experiments with rats, we assessedthe role of the associative status of the acquisition context in both the weakness of AAC renewal andthe sometimes observed weaker renewal resulting from an ABC design relative to an ABA design. InExperiment 1, we observed that AAC renewal relative to an AAA control group was small unless ContextA had undergone associative deflation (i.e., extinction of Context A). Deflation of Context A not onlydecreased behavioral control by the CS in the AAA condition, but increased it in the AAC condition,thereby implicating a comparator process in addition to associative summation between the CS and testcontext. In Experiment 2, an excitatory acquisition context was found to enhance the difference betweenABC and ABA renewal. Associative deflation of the acquisition context decreased ABA renewal more thanABC renewal. Thus, the associative value of the acquisition context (A) was more positively related tothe level of renewal when the target CS (X) was tested in this context than when it was tested in aneutral but equally familiar context (C), consistent with the frequently observed greater renewal in anABA condition than an ABC condition arising from associative summation of the CS and test context.These findings demonstrate that the excitatory status of the acquisition context influences the observeddegree of renewal.