title: Adaptive control deficits in attention-deficit/hyperactivity disorder (ADHD): the role of error processing.
abstract: Cognitive performance of children with attention-deficit hyperactivity disorder (ADHD) is characterized by large moment-to-moment fluctuations in cognitive control reflected by a highly inconsistent and inaccurate response style. It has been suggested that abnormal error processing underlies this failure to implement adequate control. We investigated the error-related negativity (ERN), a negative deflection in the event-related potential (ERP) time-locked to erroneous responses in 16 rigorously screened ADHD boys aged 8-12 years and 16 age-matched normal control boys during a modified Eriksen flanker paradigm with two levels of time pressure. Children with ADHD responded as fast and regularly as controls, but committed significantly more errors, particularly when facing time pressure and response conflict. ADHD children produced shorter runs of correct responses than controls. In addition, with high time pressure, error runs were prolonged relative to control children, suggesting an increase in both frequency and magnitude of temporary lapses of control. ERP amplitude differences between correct and incorrect responses were diminished in ADHD children, whereas post-error slowing remained unaffected. This pattern of results indicates that a specific deficit in monitoring ongoing behaviour, rather than insufficient strategic adjustments, gave rise to performance limitations in ADHD. Findings are discussed in terms of anterior cingulate cortex (ACC) dysfunction, leading to a failure to predict the likelihood that an error occurs in a given context.
authors.affiliation: Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, Van der Boechorststraat 1 1081 BT Amsterdam, The Netherlands. csmeel@fsw.leidenuniv.nl
authors.forename: Catharina S
authors.initials: CS
authors.lastname: van Meel
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Heslenfeld
authors.forename: Jaap
authors.initials: J
authors.lastname: Oosterlaan
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Sergeant
mesh_terms: D001288:Attention / Q000502:physiology*; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D003118:Color Perception / Q000502:physiology*; D003220:Conflict, Psychological; D003265:Contingent Negative Variation / Q000502:physiology*; D003657:Decision Making / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology; D005071:Evoked Potentials / Q000502:physiology; D005425:Flicker Fusion / Q000502:physiology; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009949:Orientation / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D012815:Signal Processing, Computer-Assisted