Prospective Memory is Resistant to Build-up of Proactive Interference

Proactive interference (PI), or memory impairment due to previously learned items, has been studied extensively in retrospective memory (RetroM). PI builds up rapidly when items learned recently are similar to those learned previously (e.g., all animal words). Release is observed if items learned subsequently are no longer similar (e.g., profession words), and memory improves. In six experiments, we examined whether a similar build-up and release would also be observed in prospective memory (ProM), which is memory for future intentions. In Experiments 1-5, although the usual findings were replicated in RetroM, there was no evidence of build-up of PI in ProM. Memory for the same words was unaffected when they served as ProM cues but impaired when they served as the to-be-recalled RetroM words. In Experiment 6, when the ProM and RetroM tasks were combined into a single task, a comparable build-up and release was observed in ProM, as well. Our findings suggest qualitative differences in ProM retrieval processes and we suggest that it is primarily the recursive remindings (Block & Zakay, 2006) that enable ProM to stay resistant to build-up.