Reduced REM and N2 sleep, and lower dream intensity predict increased mind-wandering

Mind-wandering, where attention shifts from the present to internal thoughts, is more likely after nights with less REM and N2 sleep and less intense dream experiences. Over 7 nights, 67 healthy participants wore mobile sleep EEG headbands and completed self-reports, yielding about 400 analyzable nights. Nights with more wakefulness and shorter REM and slow wave sleep were linked to poorer subjective sleep quality. Reduced REM and N2 sleep, along with less vivid dreams, predicted increased mind-wandering the following day. The findings highlight that night-to-day variations in specific sleep stages influence both perceived sleep quality and daytime mind-wandering intensity.

Study at a glance

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 electroencephalographic (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 slow wave sleep were associated with poorer subjective sleep quality at the intraindividual 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 intraindividual 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 intraindividual, night-to-day associations between nighttime sleep and the next day's subjective experiences.