An examination of the association between chronic sleep restriction and electrocortical arousal in college students

• Chronic sleep deficits across an academic semester impair vigilant attention.
• Changes in circadian rhythm activity and average daily sleep are each associated with changes in cortical arousal.
• Very small changes in sleep have a profound effect on neurocortical functioning.

ObjectiveThe deleterious neurocognitive effects of laboratory-controlled short-term sleep deprivation are well-known. The present study investigated neurocognitive changes arising from chronic sleep restriction outside the laboratory.MethodsSleep patterns of 24 undergraduates were tracked via actigraphy across a 15-week semester. At the semester beginning, at a midpoint, and a week before finals, students performed the Psychomotor Vigilance Test (PVT) and cortical arousal was measured via event-related potentials (ERP) and resting state electroencephalography (EEG).ResultsAverage daily sleep decreased between Session 1 and Sessions 2 and 3. Calculated circadian rhythm measures indicated nighttime movement increased and sleep quality decreased from Sessions 1 and 2 to Session 3. Parallel to the sleep/activity measures, PVT reaction time increased between Session 1 and Sessions 2 and 3 and resting state alpha EEG reactivity magnitude and PVT-evoked P3 ERP amplitude decreased between Session 1 and Sessions 2 and 3. Cross-sectional regressions showed PVT reaction time was negatively associated with average daily sleep, alpha reactivity, and P3 changes; sleep/circadian measures were associated with alpha reactivity and/or P3 changes.ConclusionsSmall, but persistent sleep deficits reduced cortical arousal and impaired vigilant attention.SignificanceChronic sleep restriction impacts neurocognition in a manner similar to laboratory controlled sleep deprivation.