Sleeping to Remember: Spontaneous Retrieval of Prospective Memories Across Sleep and Wake Delays

Laboratory-based prospective memory tasks have rarely examined the effect of retention interval on later remembering. In the current study, participants had to remember to perform an intended action: press Q in response to a target cue) after a short delay: approximately 20 min), a 12-hr sleep delay, or a 12-hr wake delay. The results demonstrated a large decline in prospective memory performance after a 12-hr wake delay: relative to the short delay condition). Interestingly, prospective remembering was not only better following a 12-hr sleep delay than a 12-hr wake delay but performance in this condition did not differ significantly from performance in the short delay condition. Cost analyses: i.e., ongoing task performance decline associated with embedding a prospective memory task) demonstrated that spontaneous retrieval processes primarily supported prospective remembering. These results are discussed in relation to theories of prospective memory retrieval and sleep-dependent memory consolidation