title: Error and feedback processing in children with ADHD and children with Autistic Spectrum Disorder: an EEG event-related potential study.
abstract: OBJECTIVE
  Performance monitoring was investigated in typically developing (TD) children, children with Autistic Spectrum Disorder (ASD), and Methylphenidate (Mph)-treated and medication-free children with Attention Deficit Hyperactivity Disorder (ADHD).
  
  
  METHODS
  Subjects performed a feedback-based learning task. Event-related Potentials (ERPs) time locked to responses and feedback were derived from the EEG.
  
  
  RESULTS
  Compared to the TD and ASD groups, the medication-free ADHD group showed a decreased response-locked Error Related Negativity (ERN) and error Positivity (Pe), particularly as learning progressed throughout the task. Compared to the medication-free ADHD group, the Methylphenidate-treated group showed a normalised Pe. All clinical groups showed or tended to show a decreased feedback-locked late positive potential to negative feedback.
  
  
  CONCLUSIONS
  The ERPs suggest that medication-free children with ADHD, but not with ASD, have a diminished capacity to monitor their error responses when they are learning by performance feedback. This capacity partially 'normalises' in Mph-treated children with ADHD. Both children with ADHD and children with ASD are suggested being compromised in affective feedback processing.
  
  
  CONCLUSIONS
  This study shows that measuring ERPs of error and feedback processing is a useful method for (1) dissociating ADHD from ASD and (2) elucidating medication effects in ADHD on component processes of performance monitoring.
authors.affiliation: Department of Psychiatry, University Medical Center Groningen, University of Groningen, P.O. Box 660, 9700 AR Groningen, The Netherlands. y.groen@accare.nl
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Groen
authors.forename: Albertus A
authors.initials: AA
authors.lastname: Wijers
authors.forename: Lambertus J M
authors.initials: LJ
authors.lastname: Mulder
authors.forename: Brenda
authors.initials: B
authors.lastname: Waggeveld
authors.forename: Ruud B
authors.initials: RB
authors.lastname: Minderaa
authors.forename: Monika
authors.initials: M
authors.lastname: Althaus
mesh_terms: D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D001321:Autistic Disorder / Q000503:physiopathology*; D002648:Child; D003265:Contingent Negative Variation / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005246:Feedback / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009716:Numerical Analysis, Computer-Assisted; D010775:Photic Stimulation; D011337:Probability Learning; D011930:Reaction Time; D011795:Surveys and Questionnaires; D013997:Time Factors