Dissociable effects of sleep deprivation on functional connectivity in the dorsal and ventral default mode networks

Objective: To examine changes in functional connectivity of the default mode network (DMN) that are induced by sleep deprivation, and to identify individual differences that contribute to the vulnerability of the brain's response to sleep deprivation. Methods: Using functional magnetic resonance imaging, we scanned 51 healthy young subjects during the resting state. Of these participants, 28 were scanned following 24 h of sleep deprivation, and 23 age and education-matched control subjects were scanned after being well rested. Results: Independent component analysis was conducted to identify the DMN. Unlike previous studies that consider the DMN as one homogeneous network, the present study found a dissociable effect of sleep deprivation on two subsystems of the DMN. Functional connectivity within the dorsal DMN decreased; this was correlated with longer response times in a psychomotor vigilance task (PVT). An enhanced functional connectivity was found within the ventral DMN as well as between two subsystems, after sleep deprivation. In addition, between-subsystems connectivity was positively correlated with working memory and negatively correlated with the response time of PVT, suggesting a possible compensatory effect of enhanced communication across two subsystems. Conclusions: The present findings suggest a dissociable effect of sleep deprivation on functional connectivity in the DMN. Lower functional connectivity in dorsal DMN was related to impairments of basic cognitive function. Notably, working memory was positively correlated with the putative compensatory enhanced functional connectivity across two subsystems, which in turn correlated with behavioral performance after sleep deprivation; this suggests that good working memory may play a protective role in sleep deprivation. (C) 2018 Elsevier B.V. All rights reserved.