title: Resting-state EEG gamma activity in children with attention-deficit/hyperactivity disorder.
abstract: OBJECTIVE
  Children with Attention-Deficit/Hyperactivity Disorder (AD/HD) have well-described abnormalities in the four traditional EEG bands. However, to date the gamma band has not been widely investigated. This study investigated resting-state EEG in children with AD/HD and matched controls, with a particular focus on gamma activity.
  
  
  METHODS
  Forty children with AD/HD, and 40 age- and sex-matched controls, participated. EEG was recorded from 19 sites during an eyes-closed resting condition and Fourier transformed to provide estimates for absolute and relative power in the delta, theta, alpha, beta and gamma bands.
  
  
  RESULTS
  Children with AD/HD had elevated levels of absolute delta and theta power, and decreased levels of absolute beta and gamma power, compared to controls. With relative power measures, children with AD/HD showed enhanced delta and theta activity, with reduced alpha, beta and gamma activity. Inattention scores on the Conners' Parent Rating Scale were negatively correlated with absolute gamma.
  
  
  CONCLUSIONS
  These patients demonstrate the typical EEG profile in the eyes-closed resting state, over the delta, theta, alpha and beta bands, associated with AD/HD. In addition, compared with controls, they demonstrate reduced absolute and relative gamma activity. These differences appear to contribute importantly to their dysfunctional stimulus processing, and impact their behavioural outcomes.
  
  
  CONCLUSIONS
  This resting-state study extends the well-established fast-wave EEG deficits in children with AD/HD to the gamma band, and links that to increased inattention, which is of special importance in understanding their cognitive-processing problems.
authors.affiliation: Brain & Behaviour Research Institute and School of Psychology, University of Wollongong, Wollongong 2522, Australia. Robert_Barry@uow.edu.au
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Barry
authors.forename: Adam R
authors.initials: AR
authors.lastname: Clarke
authors.forename: Mihaly
authors.initials: M
authors.lastname: Hajos
authors.forename: Rory
authors.initials: R
authors.lastname: McCarthy
authors.forename: Mark
authors.initials: M
authors.lastname: Selikowitz
authors.forename: Franca E
authors.initials: FE
authors.lastname: Dupuy
mesh_terms: D001288:Attention / Q000502:physiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000503:physiopathology*; D001611:Beta Rhythm; D002648:Child; D003700:Delta Rhythm; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D012146:Rest / Q000502:physiology* / Q000523:psychology; D013826:Theta Rhythm