Nighttime sleep benefits the prospective component of prospective memory.

Studies suggest that sleep benefits event-based prospective memory, which involves carrying out intentions when particular events occur. Prospective memory has a prospective component (remembering that one has an intention), and a retrospective component (remembering when to carry it out). As effects of sleep on retrospective memory are well established, the effect of sleep on prospective memory may thus be due exclusively to an effect of sleep on its retrospective component. Therefore, the authors investigated whether nighttime sleep improves the prospective component of prospective memory, or a retrospective component, or both. In a first session, participants performed an event-based prospective-memory task (that was embedded in an ongoing task) 3 minutes after forming an intention and, in a second session, 12 hours after forming an intention. The sessions were separated by either nighttime sleep or daytime wakefulness. The authors disentangled prospective-memory performance into its retrospective and prospective components via multinomial processing tree modeling. There was no effect of sleep on the retrospective component, which may have been due to a time-of-day effect. The prospective component, which is the component unique to prospective memory, declined less strongly after a retention interval filled with sleep as compared with a retention interval filled with wakefulness. A hybrid interaction suggested that refreshed attention after sleep may account for this effect, but did not support the consolidation of the association between the intention and its appropriate context as a mechanism driving the effect.

Are subjective sleepiness and sleep quality related to prospective memory?

Event-based prospective memory (PM) involves carrying out intentions when specific events occur and is ubiquitous in everyday life. It consists of a prospective component (remembering that something must be done) and a retrospective component (remembering what must be done and when). Subjective sleep-related variables may be related to PM performance and an attention-demanding prospective component. In two studies, the relationship of subjective sleepiness and subjective sleep quality with both PM components was investigated with a laboratory PM task and separation of its components via Bayesian multinomial processing tree modeling. In Study 1, neither component of PM was related to naturally occurring subjective sleepiness or sleep quality. In Study 2, sleepiness was experimentally increased by placing some participants in a supine body posture. Testing participants in upright vs. supine posture affected neither PM component. However, body posture moderated the relationship between subjective sleep quality and the prospective component: In supine posture, subjective sleep quality tended to be more positively related to the prospective component. Overall, neither subjective sleepiness nor subjective sleep quality alone was related to PM.

Is prospective memory related to depression and anxiety? A hierarchical MPT modelling approach.

Prospective memory (PM) refers to remembering to perform an action in the future. One hundred and twenty-nine students completed a laboratory event-based PM task as well as depression and anxiety questionnaires. The data were analysed with the beta-MPT version of the multinomial processing tree model of event-based PM. Thereby, the prospective and retrospective components of PM were estimated for each participant and were then correlated with depression and anxiety. State anxiety was negatively correlated with the prospective component of PM. Neither depression nor trait anxiety were related to either component of PM.