Title
To wake or not to wake? The two-sided nature of the human K-complex.
Abstract
Sleep fosters performance but likewise renders creatures insensitive to environmental threat. The brain balances between sleep promotion and protection during light sleep. One associated electrophysiological hallmark is the K-complex (KC), the sleep promoting versus arousal inducing role of which is under debate. We examined 37 subjects using EEG-combined fMRI and found KC-associated positive BOLD signal changes in subcortical (brainstem, thalamus), sensory and motor, midline and regions which form part of the default mode network, and negative changes in the anterior insula. Connectivity analysis revealed the primary auditory cortex as the first region to be influenced during the KC and that midline regions activated successively from front to back in association with the sleep protecting part of the KC. Our findings support thalamic involvement in KC mediation and an association of KCs with subcortical arousal mechanisms: activations in sensory areas suggest the existence of low level information processing during KC limited by anterior insula disengagement suggesting a two-sided nature of the KC: it embodies an arousal with subsequent sleep-guarding counteraction that might on the one hand serve periodical monitoring of the environment with basic information processing and on the other hand protect the continuity of sleep and thus its restoring effect.
Year
DOI
Venue
2012
10.1016/j.neuroimage.2011.09.013
NeuroImage
Keywords
Field
DocType
K-complex,Sleep,EEG,fMRI,Dynamic Causal Modeling,Thalamus,Saliency network
Thalamus,Auditory cortex,Arousal,Developmental psychology,Default mode network,Neuroscience,Psychology,K-complex,Sensory system,Electroencephalography,Brainstem
Journal
Volume
Issue
ISSN
59
2
1053-8119
Citations 
PageRank 
References 
13
1.04
6
Authors
7
Name
Order
Citations
PageRank
Kolja Jahnke1523.58
Frederic von Wegner21089.13
Astrid Morzelewski3805.00
Sergey Borisov4805.33
Marcella Maischein5131.04
Helmuth Steinmetz6403.62
H Laufs744538.97