Are electrophysiological correlates of response inhibition linked to impulsivity and compulsivity? A machine-learning analysis of a Go/Nogo task.

Heightened impulsivity and compulsivity are often found in association with both dysfunctional everyday behavior and with psychopathology. Impulsivity and compulsivity are also linked to alterations in behavioral response inhibition and its electrophysiological correlates. However, they are rarely examined jointly and their effect outside of clinical samples is still disputed. This study assesses the influence and interaction of impulsivity and compulsivity as measured by questionnaires (Barratt Impulsiveness Scale, UPPS Impulsive Behavior Scale, and Obsessive-Compulsive Inventory-Revised) on behavioral performance and event-related potentials (N2, P3a, and P3b) in a visual Go/Nogo task. Data from 250 participants from the general population (49% female; age M = 25.16, SD = 5.07) were collected. We used robust linear regression as well as regression tree analyses, a type of machine learning algorithm, to uncover potential non-linear effects. We did not find any significant relationship between the self-report measures and behavioral or neural inhibition effects in either type of analysis, with the exception of a linear effect of the lack of premeditation subscale of the UPPS Impulsive Behavior Scale on behavioral performance. The current sample size was large enough to uncover even small effects. One possibility is that inhibitory performance was unimpaired in a non-clinical sample, suggesting that the effect of these personality traits on inhibition and cognitive control may require a clinical sample or a more difficult task version. Further studies are needed to uncover possible associations and interactions to delineate when impulsivity and compulsivity lead to dysfunctional everyday behavior and psychopathology.