title: Altered response-preparation in patients with adult ADHD: A high-density ERP study.
abstract: Aberrations in early-developing bottom-up processes, such as stimulus-driven response preparation, are thought to play a critical role in the onset of ADHD, and in its persistence over time. Electrophysiology offers a unique tool to gain insight into response preparation, since response preparation has been associated with distinctive ERP changes, including negative potential-shifts which occur predominantly over frontal brain areas. We examined response-preceding negative potential shifts (RPNS) as a probe of response-preparation in adult ADHD patients by obtaining high-density event-related potentials from 33 ADHD and 29 matched healthy subjects during a Go/Nogo task using a 128-channel BioSemi recording-system. Compared to controls, ADHD patients showed enhancement of the RPNS in fronto-central brain regions in the Go condition during correct responses. This change was associated with poor performance in the Stroop incongruency-task: the greater the enhancement, the higher the proportion of errors. Moreover, the ERP-enhancement showed association with the severity of ADHD-symptoms; and with heightened response-variability. Thus, ADHD patients demonstrate neurophysiological alterations in response-preparation and response-preceding brain activity, suggestive of excessive activation of prefrontal neural circuits. Given the correlation with neuropsychological and psychopathological measures, these changes may constitute a pathway for core symptoms of ADHD, including premature and impaired response-preparation and motor-hyperactivity.
authors.affiliation: Semmelweis University, Department of Psychiatry and Psychotherapy, Budapest, Hungary.
authors.forename: Brigitta
authors.initials: B
authors.lastname: Kakuszi
authors.affiliation: Semmelweis University, Department of Psychiatry and Psychotherapy, Budapest, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Tombor
authors.affiliation: Semmelweis University, Department of Psychiatry and Psychotherapy, Budapest, Hungary.
authors.forename: Szilvia
authors.initials: S
authors.lastname: Papp
authors.affiliation: Semmelweis University, Department of Psychiatry and Psychotherapy, Budapest, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Bitter
authors.affiliation: Semmelweis University, Department of Psychiatry and Psychotherapy, Budapest, Hungary; Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA. Electronic address: czobor.pal@med.semmelweis-univ.hu.
authors.forename: Pál
authors.initials: P
authors.lastname: Czobor
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology*; D055815:Young Adult
keywords: ADHD; ERP; Response-locked; Response-preceding negative potential shifts; Response-preparation