Author ORCID Identifier
https://orcid.org/0000-0003-3519-2316
Defense Date
2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Psychology
First Advisor
Natalie Dautovich
Second Advisor
Joseph Dzierzewski
Third Advisor
Jared Keeley
Fourth Advisor
Bruce Rybarczyk
Fifth Advisor
Tushar Thakre
Abstract
Sleep is essential to overall health and well-being. Sleep health dimensions, including regularity, satisfaction, alertness/sleepiness, timing, efficiency, and duration are associated with better physical, mental, and cognitive health, including better subjective and objective cognitive functioning, across the lifespan. As individuals age into middle and older adulthood there are expected normative changes in sleep, including shorter and more fragmented sleep, and cognitive functioning, including changes in memory, attention, and executive functioning. How sleep health, including global sleep health, sleep regularity, and daytime sleepiness, is associated with subjective and objective cognitive functioning in middle and older adulthood remains poorly understood. Dzierzewski and colleagues (2022) proposed a model outlining several psychological and social mechanisms (e.g., depression, anxiety, loneliness, physical activity) that may underlie associations between sleep and subjective and objective cognition. This study investigated how sleep health, including global sleep health, sleep regularity, and sleepiness, is associated with both subjective and objective cognition in a sample of middle-aged and older adults. Further, this study explored potential demographic and clinical moderators, and psychosocial mediators of this association.
Participants included 370 middle-aged and older adults aged 55+ who completed an online survey through Amazon’s MTurk with questionnaires related to sleep health (RUSATED, Sleep Regularity Questionnaire (SRQ), Karolinska Sleepiness Scale (KSS)), subjective cognitive function (PROMIS-Cognitive Function Scale), mood (PHQ-9, GAD-7, De Jong Gierveld Loneliness Scale), physical activity, and sedentary behavior. After the survey, participants completed online objective cognitive testing through CANTAB, measuring attention, memory, executive function, and impulsivity. Correlational and regression analyses were utilized to examine how sleep health was associated with subjective and objective cognition. Moderation and parallel mediation analyses were utilized to explore how demographic, clinical, and psychosocial variables impacted associations between sleep health and cognition.
Better sleep health, including higher global sleep health, sleep regularity, and lower sleepiness, was associated with better subjective cognitive function and objective cognitive performance. Notably, specific dimensions of sleep health appeared to have differential impacts on objective cognition, with sleepiness being particularly salient for attention and regularity for executive functioning. Probable insomnia status moderated associations, such that those with probable insomnia exhibited a weaker or non-significant association between better sleep health and cognition compared to those without probable insomnia, suggesting that clinical sleep disturbances may impact how sleep health is associated with cognition. Further, anxiety and sedentary behavior were consistent mediators of sleep health—cognition associations, supporting the model proposed by Dzierzewski and colleagues (2022) that psychosocial variables likely underlie these associations. Taken together, these findings suggest that sleep health, not just disordered sleep, is strongly associated with subjective and objective cognitive function. Further, those with elevated insomnia symptoms may not experience the same associations between better sleep health characteristics and cognitive function. Lastly, psychosocial variables, particularly anxiety and sedentary behavior, may underlie the associations between sleep health and cognitive function.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
4-10-2026