Association Between Sleep, Cognitions about Sleep, and Executive Functioning in a College Student Sample: The Moderating Role of Dysfunctional Beliefs

Abstract

Sleep is essential for mental and physical health. However, as pursuing college begets new opportunities for independent living, social activities, and work/school responsibilities, undergraduate students frequently experience disruptions in sleep patterns, leading to a sleep deficit. Previous research has highlighted the negative impact of sleep deficits on daily functioning and academic performance. However, there is limited research examining how dysfunctional beliefs about sleep might influence the relationship between sleep and executive functioning. Harvey's Cognitive Model of Insomnia elucidates how dysfunctional sleep cognitions can significantly contribute to the development and maintenance of sleep difficulties through their instigation of unhelpful sleep-related behaviors (i.e. clock watching, catastrophizing, etc.). Therefore, this study aimed to address the existing gap in the literature by examining how negative sleep cognitions might moderate the relationship between sleep quantity/quality and executive functioning college students. Further, although executive functioning is often regarded as one comprehensive domain, literature has shown that it can be divided into three distinct components: inhibition (one's ability to resist automatic impulses), working memory (one's ability to hold and manipulation information in one's mind), and cognitive flexibility (one's ability to switch between different tasks and adapt to changing rules/situations). Upon studying these different components, research has shown that each component is impacted by sleep in a unique way. With this in mind, the present study aimed to expand prior literature by conducting exploratory analysis on the impact of sleep quality/quantity and dysfunctional sleep cognitions on the three components of executive functioning. Further, exploratory moderation analyses were run to assess the impact of dysfunctional sleep cognitions on the relationship between sleep and the three distinct facets of executive functioning. In accordance with the literature, it was hypothesized that both sleep duration and sleep quality would be positively correlated with executive functioning abilities. It was also hypothesized that dysfunctional sleep beliefs would moderate the relationship between sleep duration/quality and executive functioning. The hypotheses were partially supported. The results revealed no significant associations between sleep duration or insomnia severity and objective executive functioning. However, both sleep duration and insomnia severity were significantly correlated with subjective executive functioning. In moderation analyses, dysfunctional sleep beliefs did not significantly affect objective executive functioning or moderate the relationship between insomnia severity and subjective executive functioning. However, these beliefs did moderate the relationship between sleep duration and subjective executive functioning; this pattern remained consistent across the facets of inhibition, cognitive flexibility, and working memory. Regarding specific predictors, sleep duration was found to influence overall subjective executive functioning, but not any of the specific executive functioning facets, suggesting that other factors may have a stronger influence on the individual components. In fact, the primary factor found to exert its effect over these three components was dysfunctional beliefs about sleep. However, this predictor effect, as well as any moderation effect, diminished when insomnia severity was included in the model, which may indicate that insomnia severity accounts for much of the variance attributed to dysfunctional sleep beliefs. Insomnia severity itself had a strong impact on perceived executive functioning, and when dissected, on the facets of inhibitory control and cognitive flexibility. However, insomnia severity did not significantly predict working memory scores, which may suggest that working memory may be more resistant to the effects of sleep disturbances and dysfunctional sleep beliefs. Clinical implications of these results are discussed, and future directions of this research are encouraged in order to continue growing the literature regarding the complex relationship between these variables.