Functional Brain Network Stability Reflects Individual Resilience during Sleep Deprivation.
STUDY OBJECTIVES Sleep deprivation is known to impair cognitive performance, but individuals differ in their ability to maintain function under sleep loss. This study examined the neural mechanisms that support such resilience by tracking changes in resting-state functional connectivity during prolonged wakefulness. METHODS Six resting-state fMRI sessions obtained during approximately the first 32 hours of a 39-hour total sleep deprivation protocol were analyzed in sixteen healthy adults, enabling unusually dense longitudinal sampling of brain network dynamics during prolonged wakefulness. Functional connectivity changes were analyzed using network-based statistics as the primary approach for analyzing pairwise functional connectivity, with nodal strength used as a secondary node-level follow-up analysis in relation to a behavioral resilience index derived from psychomotor vigilance performance. RESULTS Two NBS-defined subnetworks, referred to here as the thalamocortical and perceptual-memory subnetworks, showed significant interactions between time awake and resilience, indicating that the trajectory of functional connectivity across prolonged wakefulness differed as a function of behavioral resilience. Participants with higher resilience showed less negative connectivity trajectories within these networks, particularly in the thalamus, globus pallidus, and visual cortex. In contrast, participants with lower resilience exhibited progressive declines in connectivity. CONCLUSION The ability to withstand the cognitive effects of sleep deprivation appears to be associated with less negative connectivity trajectories within thalamocortical and perceptual-memory subnetworks. These patterns may represent state-dependent neural correlates of resilience during sleep deprivation and may be relevant to future fatigue-state monitoring.