Open AccessDoes sleep restore the topology of functional brain networks?
Author(s) -
Koenis Maria M.G.,
Romeijn Nico,
Piantoni Giovanni,
Verweij Ilse,
Van der Werf Ysbrand D.,
Van Someren Eus J.W.,
Stam Cornelis J.
Publication year - 2013
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.21455
Subject(s) - wakefulness , electroencephalography , resting state fmri , neuroscience , functional connectivity , sleep deprivation , small world network , sleep (system call) , clustering coefficient , psychology , coupling (piping) , eyes open , computer science , complex network , mathematics , circadian rhythm , cluster analysis , artificial intelligence , combinatorics , balance (ability) , operating system , mechanical engineering , engineering
Previous studies have shown that healthy anatomical as well as functional brain networks have small‐world properties and become less optimal with brain disease. During sleep, the functional brain network becomes more small‐world‐like. Here we test the hypothesis that the functional brain network during wakefulness becomes less optimal after sleep deprivation (SD). Electroencephalography (EEG) was recorded five times a day after a night of SD and after a night of normal sleep in eight young healthy subjects, both during eyes‐closed and eyes‐open resting state. Overall synchronization was determined with the synchronization likelihood (SL) and the phase lag index (PLI). From these coupling strength matrices the normalized clustering coefficient C (a measurement of local clustering) and path length L (a measurement of global integration) were computed. Both measures were normalized by dividing them by their corresponding C‐s and L‐s values of random control networks. SD reduced alpha band C/C‐s and L/L‐s and theta band C/C‐s during eyes‐closed resting state. In contrast, SD increased gamma‐band C/C‐s and L/L‐s during eyes‐open resting state. Functional relevance of these changes in network properties was suggested by their association with sleep deprivation‐induced performance deficits on a sustained attention simple reaction time task. The findings indicate that SD results in a more random network of alpha‐coupling and a more ordered network of gamma‐coupling. The present study shows that SD induces frequency‐specific changes in the functional network topology of the brain, supporting the idea that sleep plays a role in the maintenance of an optimal functional network. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.