The goal of this research was to determine whether and how people deactivate prospective memory (PM) intentions after they have been completed. One view proposes that PM intentions can be deactivated after completion, such that they no longer come to mind and interfere with current tasks. Another view is that now irrelevant completed PM intentions exhibit persisting activation, and continue to be retrieved. In Experiment 1, participants were given a PM intention embedded within the ongoing task during Phase 1, after which participants were told either that the PM task had been completed or suspended until later. During Phase 2, participants were instructed to perform only the ongoing task and were periodically prompted to report their thoughts. Critically, the PM targets from Phase 1 reappeared in Phase 2. All of our measures, including thoughts reported about the PM task, supported the existence of persisting activation. In Experiment 2, we varied conditions that were expected to mitigate persisting activation. Despite our best attempts to promote deactivation, we found evidence for the persistence of spontaneous retrieval in all groups after intentions were completed. The theoretical and practical implications of this potential dark side to spontaneous retrieval are discussed.
Keywords: Prospective memory; deactivation; persisting activation; spontaneous retrieval; thought probe.