Reduced REM and N2 sleep, and lower dream intensity predicts increased mind-wandering the following day

Abstract

Mind-wandering is a mental state in which attention shifts from the present environment or current task to internally driven, self-referent mental content. Homeostatic sleep pressure seems to facilitate mind-wandering as indicated by studies observing links between increased mind-wandering and impaired sleep. Nevertheless, previous studies mostly relied on cross-sectional measurements and self-reports. We aimed to combine the accuracy of objective sleep measures with the use of self-reports in a naturalistic setting in order to examine if objective sleep parameters predict the tendency for increased mind-wandering on the following day. We used mobile sleep EEG headbands and self-report scales over 7 consecutive nights in a group of 67 healthy participants yielding ~ 400 analyzable nights. Nights with more wakefulness and shorter REM and SWS were associated with poorer subjective sleep quality at the intra-individual level. Reduced REM and N2 sleep, as well as less intense dream experiences, predicted more mind-wandering the following day. Our micro-longitudinal study indicates that intra-individual fluctuations in the duration of specific sleep stages predict the perception of sleep quality as assessed in the morning, as well as the intensity of daytime mind-wandering the following hours. The combined application of sleep EEG assessments and self-reports over repeated assessments provides new insights into the subtle intra-individual, night-to-day associations between nighttime sleep and the next day’s subjective experiences.