title: EEG correlation and power during maintenance of wakefulness test after sleep-deprivation.
abstract: OBJECTIVE
  To investigate whether there are any objective EEG characteristics that change significantly between specific time periods during maintenance of wakefulness test (MWT) and whether such changes are associated with the ability to appropriately communicate sleepiness.
  
  
  METHODS
  After a night of total sleep deprivation, 12 healthy young subjects underwent a MWT whilst being instructed to communicate the experience of subjective sleepiness by pressing a button. EEG analysis consisted of average relative power and correlation between EEG signals.
  
  
  RESULTS
  A comparison of the 30 s before microsleep (MS) with 30 s before subjects communicated experience of sleepiness (PB) showed increased β correlation as well as increased power in the β band (13-20 Hz) whereas power in the θ (4.5-7.5 Hz) and α (8-12.5 Hz) band was significantly decreased. When subjects later failed to communicate the experience of subjective sleepiness before (micro-)sleep occurred, average relative power and EEG correlation were significantly higher during 30 s following lights off in the δ (1-4 Hz) band and power in the α and β bands was decreased.
  
  
  CONCLUSIONS
  EEG spectral power and correlation change significantly in specific frequency bands between different time periods of MWT. Failure to communicate sleepiness is associated with certain precursors of EEG power and correlation.
  
  
  CONCLUSIONS
  This study demonstrates that there are specific EEG characteristics associated with impending failure to communicate sleepiness.
authors.affiliation: Department of Neurology, Inselspital, Bern University Hospital, University Bern, Switzerland. heidemarie.gast@gmail.com
authors.forename: Heidemarie
authors.initials: H
authors.lastname: Gast
authors.forename: Kaspar
authors.initials: K
authors.lastname: Schindler
authors.forename: Christian
authors.initials: C
authors.lastname: Rummel
authors.forename: Uli S
authors.initials: US
authors.lastname: Herrmann
authors.forename: Corinne
authors.initials: C
authors.lastname: Roth
authors.forename: Christian W
authors.initials: CW
authors.lastname: Hess
authors.forename: Johannes
authors.initials: J
authors.lastname: Mathis
mesh_terms: D000328:Adult; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography / Q000379:methods; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology*; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult