Sleeping poorly is robustly associated with a tendency to engage in spontaneous waking thought

We spend approximately-one third of our lives sleeping, and spontaneous thoughts dominate around 20-50% of our waking life, but little is known about the relation between the two. Studies examining this relationship measured only certain aspects of sleep and certain forms of spontaneous thought, which is problematic given the heterogeneity of both conceptions. The scarce literature suggests that disturbed sleep and the frequency of spontaneous waking thoughts are associated, however this could be caused by shared variance with negative affect. We report a comprehensive survey study with a large range of self-reported sleep and spontaneous thought measures (N = 236), showing that poorer sleep quality, more daytime-sleepiness, and more insomnia symptoms, consistently predicted higher tendencies to engage in disruptive spontaneous thoughts, independently of trait negative affect, age and gender. Contrarily, only daytime sleepiness predicted positive-constructive daydreaming. Findings underscore the role of sleep for spontaneous cognition tendencies.

Automated summary

We spend a significant portion of our lives sleeping and experiencing spontaneous thoughts. However, little is known about the relationship between sleep and spontaneous thoughts. Previous studies have focused on specific aspects of sleep and certain forms of spontaneous thought, which limits the understanding of this relationship. This comprehensive survey study suggests that poorer sleep quality, daytime sleepiness, and insomnia symptoms are consistently associated with disruptive spontaneous thoughts, while only daytime sleepiness is related to positive-constructive daydreaming.