Great Expectations: Anticipating a Reminder Influences Prospective Memory Encoding and Unaided Retrieval

Abstract

The current study tested the idea that expecting a reminder reduces unaided prospective memory (PM) retrieval by reducing encoding effort (i.e., encoding effort hypothesis) and over-reliance on reminders reduces internal memory ability (i.e., use-it-or-lose-it hypothesis). To test this idea, participants completed four PM task blocks. Two reminder conditions had reminders for the first three blocks, but not on the fourth. Critically, the non-expecting reminder condition was told they would not have a reminder prior to encoding targets in the fourth block, while the expecting reminder condition was told they would have a reminder. A no reminder control never had a reminder. The encoding effort hypothesis was supported by showing that expecting a reminder in the fourth block reduced unaided PM retrieval and retrospective memory target recognition (Experiments 1 and 2), while deep processing at encoding negated these effects (Experiment 3). The use-it-or-lose-it hypothesis was not supported, as memory in the fourth block was similar between the non-expecting reminder and no reminder conditions. Our results suggest expecting a reminder reduces encoding effort, which negatively impacts PM when reminders are unavailable. We propose the PM Effort Monitoring and Control Framework to describe how experiencing the effectiveness of retrieval with reminders with low effort (blocks 1-3) leads to a less effortful encoding strategy when they expect another reminder during a subsequent PM task (block 4).