Subjectively and Objectively Measured Sleep Predict Differing Aspects of Cognitive Functioning in Adults.

Abstract

Objective: To examine associations between subjectively-reported sleep and objectively-measured sleep (i.e., actigraphy) with different domains of cognitive functioning, and determine whether age may moderate these associations.

Method: In this cross-sectional study, a total of 489 participants (mean age = 45.4 years; SD = 18.8) completed a self-reported sleep measure and one week of actigraphy. Participants also completed a battery of cognitive tests measuring episodic memory, social cognition, executive functioning, and complex cognition (i.e., reasoning, visuospatial, and language abilities).

Results: Multiple regression analyses revealed that greater objective sleep quality and longer onset latencies were both associated with better performance on measures of conceptual flexibility. In contrast, subjective sleep quality was not associated with performance in any cognitive domain after accounting for objective sleep variables. Age moderated sleep-cognition relationships in differing ways based on cognitive domain and facet of sleep assessed. For example, whereas poorer subjective sleep quality was associated with poorer complex cognition in younger, but not older adults, poorer objective sleep quality was associated with poorer conceptual flexibility in older, but not younger adults.

Conclusions: Objectively-measured and self-reported sleep are associated with differing aspects of executive functioning, with the latter related to executive functioning broadly and the former associated with conceptual flexibility in particular. Age moderates sleep-cognition relationships differentially depending on the method by which sleep quality and quantity are measured.