Electrophysiological correlates of behavioral response inhibition in patients with obsessive–compulsive disorder

Abstract

In this study, we have attempted to determine the electrophysiological correlates of behavioral response inhibition in patients with obsessive-compulsive disorder (OCD). To evaluate response inhibition ability, we have used the Go/NoGo task and measured N2 and P3 event-related potential (ERP) components. Both the OCD and control groups exhibited greater and more frontally distributed N2 and P3 amplitudes in the NoGo condition compared to what we observed in the Go condition. However, the patients with OCD also manifested reduced NoGo-N2 and Go-N2 amplitudes at the frontocentral electrode sites compared to the controls. In addition, the NoGo-N2 amplitudes were more posteriorly distributed in patients with OCD than in controls. The NoGo-N2 amplitudes and latencies measured at the central sites were also negatively correlated with the obsession score on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). The OCD and control groups were comparable with regard to Go-P3 and NoGo-P3 amplitude and latencies. Our findings suggest dysfunctions in frontal regions mediating response inhibition in OCD, consistent with the involvement of response inhibition in the pathophysiology of this disorder. In addition, NoGo-N2 seems to result in more accurate response inhibition measurements in patients with OCD than does NoGo-P3. Depression and Anxiety 24:22-31, 2007.

Electrophysiological evidence for reduced inhibitory control in depressed patients in partial remission: A Go/Nogo study

“…Moreover, the present findings are consistent with the study by Chiu and Deldin (2007) and two recent studies which demonstrated a response inhibition deficit in patients with obsessivecompulsive disorder (Herrmann et al, 2003;Kim et al, 2007) but no between group differences in behavioural data. Contrary to that, Zhang et al (2007) found longer reaction times and greater incidence of commission errors in their MDD patients compared to control subjects.…”

“…The Nogo-N2 has been argued to reflect response inhibition, i.e. a top-down mechanism to suppress the incorrect tendency to respond operating at a processing stage prior to motor execution (Falkenstein et al, 1999;Kaiser et al, 2003;Kim et al, 2007). Contrary to that, Nieuwenhuis et al (2003) and Donkers and van Boxtel (2004) suggested that the N2 mirrors conflict monitoring rather than response inhibition as Nogo "responses" compete and conflict with overt responses.…”

Separating distinct aspects of the voluntary selection between response alternatives: N2- and P3-related BOLD responses

“…However, the differences between the voluntary selection task and the other experimental conditions (control, nogo, go) failed to be significant, probably due to a relatively high variability regarding timing and the N2 amplitude between subjects. Generally, the N2 has been associated with the top-down inhibition processes in order to suppress the incorrect tendency to respond (Falkenstein et al, 1999;Kim et al, 2007) as well as the response conflict caused by the necessity to respond to low-frequency stimuli (Bartholow et al, 2005;Donkers and van Boxtel, 2004;Nieuwenhuis et al, 2003).…”

The free choice whether or not to respond after stimulus presentation

“…The N2 has been associated with the top-down inhibition processes in order to suppress the incorrect tendency to respond [Falkenstein et al, 1999;Kim et al, 2007]. More recently, it has also been related to response conflict caused by the necessity to respond to low-frequency stimuli, regardless of the kind of response requested [Bartholow et al, 2005;Donkers and van Boxtel, 2004;Nieuwenhuis et al, 2003].…”