Limited Benefit of Sleep Extension on Cognitive Deficits During Total Sleep Deprivation: Illustration With Two Executive Processes

Abstract

Introduction: Sleep extension has been associated with better alertness and sustained attention capacities before, during and after sleep loss. However, less is known about such beneficial effect on executive functions (EFs). Our aim was to investigate such effects on two EFs (i.e., inhibition and working memory) for subjects submitted to total sleep deprivation and one-night of recovery. Methods: Fourteen healthy men (26–37 years old) participated in an experimental cross-over design with two conditions: extended sleep (EXT, 9.8 ± 0.1 h of Time In Bed, TIB) and habitual sleep (HAB, 8.2 ± 0.1 h TIB). During these two conditions subjects underwent two consecutive phases: Six nights of either EXT or HAB followed by 3 days in-laboratory: baseline (BASE), TSD (38 h) and after recovery (REC). EFs capacities were assessed through Go-NoGo (inhibition) and 2N-Back (working memory) tasks. Both EFs capacities were measured at different time (BASE/TSD/REC: 09:30, 13:00, 16:00; TSD: 21:00, 00:00, 03:00, 06:30). Results: In both conditions (HAB and EXT), TSD was associated with deficits in inhibition (higher errors and mean reaction time from TSD 09:30 until the end; p < 0.05) and working memory (lower corrects responses from TSD 06:30 or 09:30; p < 0.05). We observed no significant differences between HAB and EXT conditions on EFs capacities during BASE, TSD, and REC periods. Conclusion: Six nights of sleep extension is neither efficient to reduce core EFs deficits related to TSD nor to improve such capacities after a recovery night. These results highlight that sleep extension (six nights of 10 h of TIB) is not effective to limit EFs deficits related to TSD suggesting a disconnection inside cognition between executive and sustained attention processes. Clinical Trials: NCT02352272.

Decreased resting-state alpha-band activation and functional connectivity after sleep deprivation

“…After a night of recovery sleep following sleep deprivation, alpha-band activation and functional connectivity did not return to normal levels, indicating that one night of sleep recovery cannot eliminate the damage caused by 36 of sleep deprivation. In general, sleep has a recovery and organizing effect on the cortical activity of wakefulness [56,57]. Although the sleep recovery effect was not signi cant in our results, the difference between RS and SD sessions was smaller than the difference between NS and SD sessions, thus con rming the homeostatic regulation of sleep to a certain extent [58].…”

Decreased resting-state alpha-band activation and functional connectivity after sleep deprivation

“…After a night of recovery sleep following sleep deprivation, alpha-band activation and functional connectivity did not return to normal levels, indicating that one night of sleep recovery cannot eliminate the damage caused by 36 h of sleep deprivation. In general, sleep has a recovery and organizing effect on the cortical activity of wakefulness 30 , 53 . Although the sleep recovery effect was not significant in our results, the difference between RS and SD sessions was smaller than the difference between NS and SD sessions, thus confirming the homeostatic regulation of sleep to a certain extent 54 .…”

Impaired Vigilant Attention Partly Accounts for Inhibition Control Deficits After Total Sleep Deprivation and Partial Sleep Restriction

“…For instance, one study demonstrated that six nights of sleep extension before sleep deprivation did not reduce inhibition control deficits during a total sleep deprivation period. 18 By contrast, another study found that six nights of sleep extension was sufficient to reduce vigilant attention deficits related to total sleep deprivation. 82 Therefore, the effects of sleep deprivation on inhibition control likely depend on the interaction of vigilant attention, working memory, decision making, and sensory perception, among other factors.…”

“… 14 In another study in which 12 participants spent 14 days in the laboratory with 2 baseline days followed by 7 days of partial sleep restriction and 3 recovery days, researchers observed a significant sleep restriction effect on errors of commission in the Go/No-Go task. 18 However, a few studies have found no significant changes in individuals’ levels of inhibition control after TSD or PSR. 23 , 28 , 41 For example, some researchers posit that sleep deprivation does not affect inhibition per se, but rather affects a supervisory attentional process, which is regarded as an active effort to cope with a complex task.…”