Sleep Benefits to Spatial Source Memory in Older Adults

While it is well-established that sleep benefits episodic memory, most evidence is on younger adults. The current study examined sleep benefits in older adults and chose spatial source memory as a target measure for which a recent study in younger adults showed particularly strong sleep benefits (Berres et al., 2025). This corresponds to theories of sleep and memory (e.g., active systems consolidation hypothesis) which predict sleep (especially SWS) benefits in hippocampus-dependent source memory. Using the same design as Berres et al.’s (2025) Experiment 1, we tested 58 older adults (aged 60 – 86 years) who were randomly assigned to study object pictures in left versus right screen locations either in the morning (7-10am; wake group) or in the evening (7-10pm; sleep group). Testing for item (pictures) and source (location) memory followed 12 hours later (i.e., wake group: same day evening; sleep group: next morning). Multinomial model-based analyses showed that both item and, especially, source memory were significantly improved in the sleep group. Additionally, older adults in the sleep group wore FitBitChargeHR™ wristbands for sleep tracking. Based on an extended sample of n = 61 older adults in this group, we estimated correlations to sleep parameters in a Bayesian-hierarchical multinomial analysis. Contrary to expectations, time spent in deep sleep did not predict next morning’s source memory, but time spent in deep sleep embedded in sleep cycles was positively correlated with source memory the next morning. Further, time spent awake after sleep onset was negatively correlated with source memory.