Abstract
Post-conditioning manipulation of a non-target stimulus sometimes affects conditioned responses evoked by a target stimulus. In the present study, we investigated the effect of post-training extinction of a conditioned excitor on conditioned inhibition in an instrumental conditioning situation. Food reinforcement was delivered as the outcome of lever pressing following the presentation of a single discriminative stimulus (i.e., A+), but not a compound stimulus (i.e., AX-), in order to establish a conditioned inhibitor. Omission training to an excitatory discriminative stimulus (i.e., A-) following the conditioned inhibition training did not attenuate the inhibitory property of the target stimulus. These results suggested the difficulty of obtaining a retrospective revaluation effect in the conditioned inhibition of instrumental behavior. The possible associative structure of instrumental conditioning and clinical implications are discussed.
