title: Inhibition in children with attention-deficit/hyperactivity disorder: a psychophysiological study of the stop task.
abstract: BACKGROUND
  The purpose of the study was to investigate and identify abnormal brain activity, as revealed by event-related potentials (ERPs) concurring with deficient inhibitory control in children with attention-deficit/hyperactivity disorder (ADHD).
  
  
  METHODS
  Performance and ERPs from 16 children with ADHD and 16 control subjects were compared in the stop-signal paradigm.
  
  
  RESULTS
  The ADHD children showed a lower inhibition percentage and their (estimated) response time to the stop signal was disproportionally longer compared to the slowing of reaction times to primary-task stimuli. In normal control subjects, fronto-central positivity (100-400 msec) after the onset of the stop-signal was larger in case of successful inhibition, relative to failed inhibition; this was less so in ADHD children. A late positive wave (500-700 msec), maximal at Oz on failed inhibition trials, and possibly related to error-detection, was smaller in ADHD children.
  
  
  CONCLUSIONS
  These results point to abnormalities in brain processes involved in motor inhibition and error-detection in ADHD children.
authors.affiliation: Faculty of Pharmacy, Department of Psychopharmacology, Rudolf Magnus Institute for Neurosciences, Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands.
authors.forename: Carin C E
authors.initials: CC
authors.lastname: Overtoom
authors.forename: J Leon
authors.initials: JL
authors.lastname: Kenemans
authors.forename: Marinus N
authors.initials: MN
authors.lastname: Verbaten
authors.forename: Chantal
authors.initials: C
authors.lastname: Kemner
authors.forename: Maurits W
authors.initials: MW
authors.lastname: van der Molen
authors.forename: Herman
authors.initials: H
authors.lastname: van Engeland
authors.forename: Jan K
authors.initials: JK
authors.lastname: Buitelaar
authors.forename: Harry S
authors.initials: HS
authors.lastname: Koelega
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D011930:Reaction Time; D013647:Task Performance and Analysis