Reinstatement-induced recovery of a taste-LiCl association following extinction

Water-deprived rats were given a single exposure to saccharin and LiCl, either paired or unpaired. Half the subjects then received three saccharin-only exposures (extinction) in the training enclosure, followed by a single LiCl-only presentation (unconditioned stimulus reinstatement) 8 days after conditioning. The remaining subjects received six saccharin-only exposures, followed by LiCl reinstatement 13 days after conditioning. In both cases LiCl reinstatement occurred outside the training/test context. Appreciable recovery from extinction was observed after the partial loss of taste aversion obtained with three extinction sessions and the 8-day conditioning-reinstatement interval, but not after the asymptotic loss of taste aversion obtained with six extinction sessions and the 13-day conditioning-reinstatement interval. Conditioned taste aversions appear to be similar to more traditional associations with respect to both extinction and reinstatement-induced recovery from extinction. The results are discussed with reference to the event-memory, contextual-conditioning, and facilitated-retrieval hypotheses of postextinction reinstatement effects.