Interindividual Differences in the Effects of Sleep Deficiency on Cognitive Performance
Open Access
- Author:
- Mathew, Gina
- Graduate Program:
- Biobehavioral Health
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 15, 2021
- Committee Members:
- Jennifer Williams, Outside Field Member
Orfeu Buxton, Major Field Member
Michael Russell, Major Field Member
Anne-Marie Chang, Chair & Dissertation Advisor
Nancy Dennis, Outside Unit Member
Thomas Gould, Program Head/Chair - Keywords:
- sleep restriction
sleep disruption
sleep restriction
sleep disruption
cognition
performance
interindividual differences
attention
vigilance
working memory
visuospatial processing
processing speed
alertness
motivation
effort - Abstract:
- Millions of American adults experience sleep deficiency, a multidimensional construct that includes insufficient quantity and poor quality of sleep. Both experimental sleep restriction (where participants experience several days of short sleep duration) and sleep disruption (where disruptive stimuli are presented to reduce sleep quality) impair performance, impacting global cognitive domains such as attention and more domain-specific cognitive performance such as working memory, visuospatial processing, and processing speed. The degree of performance impairment during sleep restriction varies widely among individuals, though interindividual vulnerability after sleep disruption has not been studied. This dissertation examined interindividual differences in performance during sleep deficiency using data from two inpatient studies: Sleep Restriction and SoundSleeping. The Sleep Restriction study was conducted in 15 healthy young men 20-35 years of age and included three nights of 10-hour time in bed (TIB), five nights of sleep restricted to 5 hours TIB, and two recovery nights of 10 hours TIB. The SoundSleeping study was conducted in 8 healthy men and women 35-50 years of age and included a night of habituation sleep, a night including either disruptive or enhancing auditory stimuli presented during sleep, a control sham night, and a night with either disruptive or enhancing auditory stimuli during sleep (whichever condition had not occurred two nights prior; order randomized and counterbalanced across participants), with 9-hour TIB all nights. Only disruptive and sham conditions were included in current analyses. During scheduled wake time for both studies (every 2 hours for Sleep Restriction and every 3 hours for SoundSleeping), participants completed a 20-minute cognitive battery assessing attention and domain-specific cognitive performance including working memory, visuospatial processing, and processing speed. Each cognitive battery was immediately followed by a survey assessing subjective alertness, motivation, and effort. Several aspects of interindividual differences in the effect of sleep deficiency on cognitive performance were examined. Chapter 2 tested whether the changes in subjective alertness, motivation, and effort from full rest to sleep restriction moderated the impact of sleep restriction on attentional performance. Results indicated that some aspects of attentional performance were differentially moderated by the changes in subjective motivation and subjective effort during sleep restriction. Chapter 3 examined whether attentional vulnerability after sleep restriction moderated the impact of sleep restriction on domain-specific cognitive performance. Results indicated that more vulnerable participants demonstrated greater working memory and visuospatial processing impairment during sleep restriction than did less vulnerable participants. Chapter 4 examined whether the differences in subjective alertness, motivation, and effort between sleep disruption and a sham control condition moderated the impact of sleep restriction on attentional performance; there were no significant interactions. Chapter 5 examined whether attentional vulnerability after the disruptive condition moderated the impact of sleep disruption on domain-specific cognitive performance. Results indicated that comparatively less vulnerable participants rated their confidence in incorrect responses on a working memory task as lower in the disruptive versus the sham conditions. Overall, the findings suggest similar effects of sleep restriction and sleep disruption on attentional performance, but that markers of interindividual differences in attention may differ between the types of sleep deficiency. Furthermore, attentional vulnerability is a marker of working memory and visuospatial impairment after sleep restriction but not sleep disruption.