THE RELATION BETWEEN MEMORY AND EXPECTANCY AS REVEALED BY PERCENTAGE AND SEQUENCE OF REWARD INVESTIGATIONS

There is growing agreement that to explain instrumental learning prope rly, one should emphasize memory as well as expectancy. I call this ap proach memory-expectancy theory. Amsel's (1992) frustration theory is one variety of memory-expectancy theory. Capaldi's (1994) sequential t heory is another. In this report, I examine in considerable detail the effects of percentage and sequence of reward on extinction following different levels of acquisition training. These extinction findings, t aken together with certain serial learning acquisition findings, seem to support a novel version of memory-expectancy theory, one that in so me respects is similar to and in some respects is different from that suggested by Amsel. First, on the basis of this analysis, we may rejec t two ideas: that animals remember only the prior reward event and tha t animals anticipate only the reward event contingent upon the current response. Second, the analysis supports three salient propositions of the present memory-expectancy approach. Memories of reward events may serve as conditioned stimuli for expectancies of reward events. On an y current trial, the animal may remember each of the reward events ass ociated with one or more prior trials. On any current trial, the anima l may anticipate not only the current reward event, but also reward ev ents contingent upon subsequent trials. Essentially, according to this model, the stimuli that elicit expectancies, as well as the expectanc ies themselves, may change progressively over a series of learning tri als.