Abstract

An extinction cue (EC) is a discrete stimulus that is presented during Pavlovian extinction, contingent and with close contiguity to the conditioned stimulus (CS) under extinction treatment. When this EC is presented during a recovery test (e.g., renewal, spontaneous recovery), it typically prevents response recovery. At least two associative mechanisms have been proposed to explain this effect: an EC might become a conditioned inhibitor, or it might become a negative occasion setter. Three experiments, using rats as subjects, assessed whether an EC prevented renewal, and evaluated with summation and retardation tests as to whether it acquired conditioned inhibition. Experiment 1 was conducted in a fear conditioning preparation, and experiments 2 and 3 in an appetitive conditioning paradigm. The results of the three experiments showed that an EC did not attenuate renewal compared to a novel cue, and subsequent inhibition tests also showed no difference between the EC and a novel stimulus. These results suggest that the effect might be more difficult to detect than expected, and are discussed within the framework of previous studies.