Interindividual differences in mindfulness are linked to sleep-electroencephalographic characteristics

Study Objectives Mindfulness describes the ability to focus on the presence, including one’s thoughts and feelings. Trait mindfulness—a person’s inherent tendency to be mindful—has been connected to increased subjective sleep quality, but evidence from objective EEG-based sleep measures is lacking. Here, we investigate whether objective EEG-based sleep parameters explain interindividual differences in trait mindfulness. Methods Whole-night polysomnographic data were gathered from 52 healthy adults (27 females; agemean = 21.5 [SE = 0.28]) in their homes using a portable high-density EEG device. Trait mindfulness was assessed using the Five Facet Mindfulness Questionnaire short form (FFMQ-SF). Results Trait mindfulness was positively correlated at trend level with the percentage of rapid eye movement (REM), but not N1, N2, or slow wave sleep. Additionally, those exhibiting less REM beta/gamma power and NREM beta power displayed higher trait mindfulness and vice versa. Lastly, we replicated findings connecting higher trait mindfulness to better subjective sleep quality. Conclusions REM sleep is pivotal for emotional processing. Decreased REM high-frequency activity was suggested to reflect adrenergic reduction that defuses affective experiences. Increased NREM high-frequency activity is a marker for cognitive hyperarousal in insomnia. We speculate that differences in trait mindfulness might be explained by differences in REM- and NREM-sleep functions that promote ideal emotional regulation and prevent hyperarousal.