Effects of Sleep Deprivation on Functional Connectivity and Integration During Cognitive Tasks

Introduction: We previously demonstrated that sleep deprivation (SD) alters the balance of integration and segregation of brain activity in cortical networks, which was correlated to cognitive impairment following SD. The objectives of this study is to examine the effects of total sleep deprivation and recovery nap on (i) cognitive performances, (ii) functional connectivity, (iii) integration and (iv) compare changes in integration with cognitive changes during different cognitive tasks individually. We hypothesized that sleep deprivation will lead to increase integration within-networks relative to between-networks and associated with cognitive impairment for all three tasks. Methods: 20 healthy adults (MAGE=21.32, 12 females) were scanned using simultaneous EEG-fMRI during three cognitive tasks (attention, working memory, vigilance) in three conditions: following a normal night of sleep, 24-hour of total SD, and 1-hour recovery nap. A general linear model was performed to compare functional connectivity between the three conditions. Functional clustering ratio (FCR) was used to calculate integration and Pearson’s correlations was used to compare the changes in integration and cognitive changes between each conditions. Results: SD was associated with increased FCR, driven by a rise of integration within cortical networks which was associated with deficits in performance of working memory and attention tasks, but not vigilance task. Restoration of balance between integration and segregation of cortical activity was related with performance following recovery nap demonstrating bidirectional effect. Conclusions: These results demonstrate intra- and interindividual differences in cortical network integration and segregation during task performance may play a critical role in vulnerability to cognitive impairment in the SD state