Reversed and increased functional connectivity in non-REM sleep suggests an altered rather than reduced state of consciousness relative to wake.
Abstract
Sleep resting state network (RSN) functional connectivity (FC) is poorly understood, particularly for rapid eye movement (REM), and in non-sleep deprived subjects. REM and non-REM (NREM) sleep involve competing drives; towards hypersynchronous cortical oscillations in NREM; and towards wake-like desynchronized oscillations in REM. This study employed simultaneous electroencephalography-functional magnetic resonance imaging (EEG-fMRI) to explore whether sleep RSN FC reflects these opposing drives. As hypothesized, this was confirmed for the majority of functional connections modulated by sleep. Further, changes were directional: e.g., positive wake correlations trended towards negative correlations in NREM and back towards positive correlations in REM. Moreover, the majority did not merely reduce magnitude, but actually either reversed and strengthened in the opposite direction, or increased in magnitude during NREM. This finding supports the notion that NREM is best expressed as having altered, rather than reduced FC. Further, as many of these functional connections comprised "higher-order" RSNs (which have been previously linked to cognition and consciousness), such as the default mode network, this finding is suggestive of po...Continue Reading
References
Breakdown of long-range temporal dependence in default mode and attention networks during deep sleep
Towards a consensus regarding global signal regression for resting state functional connectivity MRI
Using Dual Regression to Investigate Network Shape and Amplitude in Functional Connectivity Analyses
Software Mentioned
Related Concepts
Related Feeds
Adrenocortical Carcinoma
Adrenocortical carcinoma (ACC) is a rare malignancy of the adrenal cortex, associated with a generally dismal prognosis owing to its aggressive behavior. Here are the latest discoveries pertaining to this disease.