Interactions between retroactive-interference and context-mediated treatments that impair pavlovian conditioned responding.

In Pavlovian fear conditioning, context-mediated decrements in conditioned responding (e.g., the US preexposure effect) can counteract competition between cues trained together (e.g., overshadowing). Two experiments were conducted using rats in a conditioned lick suppression preparation to determine whether context-mediated competition also counteracts competition between c ues trained separately (retroactive interference, or RI). In Experiment 1, a combination of degraded contingency and RI treatments produced less of a decrement in conditioned responding than did either of those treatments alone. Experiment 2 showed that RI treatment attenuates the normally deleterious effect of trial massing. The results suggest that empirical similarities are shared by interference between cues trained apart and competition between cues trained together.