Enhanced high-frequency precuneus-cortical effective connectivity is associated with decreased sensory gating following total sleep deprivation.

Sleep deprivation decreases an individual's cognitive function. When cognitive impairment reaches a certain level, human errors occur and may even result in accidents. Previous research has shown that sensory gating is a basic mechanism in cognitive function, but only limited studies have so far reported how it is affected by sleep deprivation. This study aimed to analyze the effects of sleep deprivation on sensory gating and its cognitive and neural mechanisms. Thirty-six healthy subjects participated in our study. The resting-state, auditory P50-task electroencephalography (EEG) recordings and the psychomotor vigilance task (PVT) were performed at resting wakefulness (RW) and after 36 h of total sleep deprivation (TSD). Changes in P50 suppression before and after sleep deprivation were recorded, and the isolated effective coherence (iCoh) was employed for analyzing effective connectivity based on EEG data during the resting-state and P50 tasks. Subjects demonstrated reduced P50 suppression and prolonged PVT reaction time after TSD compared with RW. Effective connectivity analysis of resting-state EEG data showed that sleep deprivation decreased the connectivity from the right middle occipital gyrus (RMOG)/Rcuneus to left inferior/middle temporal gyrus (LITG/LMTG) and left parahippocampal/fusiform gyrus (LPH/LFG). EEG data analysis during the P50 task showed that, in addition to the aforementioned connectivity changes, the directed high-frequency effective connectivity from the left precuneus to the left superior/middle frontal gyrus (LSFG/LMFG), LITG/LMTG, LPH/LFG, and left middle occipital gyrus (LMOG)/Lcuneus increased. P50 suppression in Cz positively correlated with PVT reaction time. This study reveals that the precuneus is a key brain region in neural network correlates of sensory gating, and that changes in its effective connectivity with other regions (including LSFG/LMFG, LPH/LFG, LMOG/LCuneus, and LITG/LMTG) are important for decreasing sensory gating after TSD.