title: Differential oscillatory electroencephalogram between attention-deficit/hyperactivity disorder subtypes and typically developing adolescents.
abstract: BACKGROUND
  A neurobiological-based classification of attention-deficit/hyperactivity disorder (ADHD) subtypes has thus far remained elusive. The aim of this study was to use oscillatory changes in the electroencephalogram (EEG) related to informative cue processing, motor preparation, and top-down control to investigate neurophysiological differences between typically developing (TD) adolescents, and those diagnosed with predominantly inattentive (IA) or combined (CB) (associated with symptoms of inattention as well as impulsivity/hyperactivity) subtypes of ADHD.
  
  
  METHODS
  The EEG was recorded from 57 rigorously screened adolescents (12 to 17 years of age; 23 TD, 17 IA, and 17 CB), while they performed a cued flanker task. We examined the oscillatory changes in theta (3-5 Hz), alpha (8-12 Hz), and beta (22-25 Hz) EEG bands after cues that informed participants with which hand they would subsequently be required to respond.
  
  
  RESULTS
  Relative to TD adolescents, the IA group showed significantly less postcue alpha suppression, suggesting diminished processing of the cue in the visual cortex, whereas the CB group showed significantly less beta suppression at the electrode contralateral to the cued response hand, suggesting poor motor planning. Finally, both ADHD subtypes showed weak functional connectivity between frontal theta and posterior alpha, suggesting common top-down control impairment.
  
  
  CONCLUSIONS
  We found both distinct and common task-related neurophysiological impairments in ADHD subtypes. Our results suggest that task-induced changes in EEG oscillations provide an objective measure, which in conjunction with other sources of information might help distinguish between ADHD subtypes and therefore aid in diagnoses and evaluation of treatment.
authors.affiliation: Academic Medical Center, Department of Psychiatry, University of Amsterdam, The Netherlands. Electronic address: ali.mazah@gmail.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Mazaheri
authors.affiliation: M.I.N.D. Institute, University of California, Davis, California; Department of Psychiatry and Behavioral Sciences, University of California, Davis, California; Imaging Research Center, University of California, Davis, California; Center for Mind and Brain , University of California, Davis, California.
authors.forename: Catherine
authors.initials: C
authors.lastname: Fassbender
authors.affiliation: Center for Mind and Brain , University of California, Davis, California.
authors.forename: Sharon
authors.initials: S
authors.lastname: Coffey-Corina
authors.affiliation: M.I.N.D. Institute, University of California, Davis, California.
authors.forename: Tadeus A
authors.initials: TA
authors.lastname: Hartanto
authors.affiliation: M.I.N.D. Institute, University of California, Davis, California; Department of Psychiatry and Behavioral Sciences, University of California, Davis, California.
authors.forename: Julie B
authors.initials: JB
authors.lastname: Schweitzer
authors.affiliation: Center for Mind and Brain , University of California, Davis, California; Department of Psychology , University of California, Davis, California; Department of Neurology, University of California, Davis, California.
authors.forename: George R
authors.initials: GR
authors.lastname: Mangun
mesh_terms: D000293:Adolescent; D041923:Adolescent Development / Q000502:physiology; D000513:Alpha Rhythm; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D001611:Beta Rhythm; D001921:Brain / Q000254:growth & development* / Q000503:physiopathology*; D002648:Child; D003463:Cues; D004569:Electroencephalography; D056344:Executive Function / Q000502:physiology*; D006801:Humans; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D013826:Theta Rhythm; D014796:Visual Perception / Q000502:physiology*
keywords: Attention-deficit/hyperactivity disorder; EEG oscillations; connectivity; cue-processing; response preparation; top-down control