Impact of daytime sleepiness and insomnia on simple and complex cognitive task performances

• Published in: Sleep medicine Vol. 87; pp. 46 - 55
• Main Authors: Edinger, Jack D., Bathgate, Christina J., Tsai, Sheila, Khassawneh, Basheer
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2021
• Subjects: Adult; Cognition; Cognitive performance; Cross-Sectional Studies; Daytime alertness; Disorders of Excessive Somnolence; Female; Humans; Hyperarousal; Insomnia disorder; Male; MSLT; Sleep Initiation and Maintenance Disorders - complications; Task Performance and Analysis; Cognitive performance; MSLT; Hyperarousal; Insomnia disorder; Daytime alertness
• ISSN: 1389-9457; 1878-5506
• DOI: 10.1016/j.sleep.2021.08.004

To examine the individual and combined effects of daytime sleepiness and insomnia disorder (ID) on measures of cognitive functioning. This study was conducted at a medical center using a cross-sectional research design. 35 persons with ID (Mage = 40.6 years; 25 women) and 54 normal sleepers (NS; Mage = 31.5 years; 38 women). Participants underwent two nights of home-based polysomnography (PSG) followed by daytime testing with a four-trial Multiple Sleep Latency Test (MSLT). Before each MSLT nap, they completed a computer-administered battery of reaction time tasks. Measures of response latencies and response accuracy were tabulated and used as dependent measures. The ID and NS groups were each subdivided into “alert” (eg, MSLT mean latency > 8 min) and “sleepy” (eg, MSLT mean latency ≤ 8 min) subgroups to identify hyperaroused persons with ID and allow for their comparisons with the other participant subgroups. Multivariate analyses of variance showed a significant main effect for level of daytime sleepiness (F [1, 84] = 8.52, p = 0.0045) on simpler performance tasks and a significant main effect for presence vs. absence of ID (F [1,84] = 6.62, p = 0.012) on complex tasks. A lack of significant participant type x MSLT alertness level interactions in study analyses suggested those ID participants with presumed hyperaousal were not relatively more impaired than the other participant subgroups. Daytime performance deficits on simple tasks seem most dependent on individuals’ levels of daytime sleepiness, whereas performance deficits on more complex tasks appears related to the presence of ID. Therefore, it seems best to use complex performance measures both to document cognitive deficits among those with ID and to determine if insomnia treatments reduce such impairments. ClinicalTrials.gov Identifier: NCT02290405. •Persons with insomnia disorder (ID) complain of daytime impairment and show more work absenteeism and traffic accidents than do normal sleepers.•Laboratory studies have not produced consistent findings in regard to documenting the daytime impairments of which those with ID complain.•The types of laboratory measures used to assess daytime impairment among those with ID may determine whether or not this impairment is evident.•Impairment on simple tasks is more the result of daytime sleepiness, per se, but level of impairment shown on complex task is more affected by the presence of ID.