Emotional context modulates response inhibition: neural and behavioral data.

Although recent hemodynamic studies indicate that neural activity related to emotion and that associated with response inhibition constitute closely interrelated and mutually dependent processes, the nature of this relationship is still unclear. In order to explore the temporo-spatial characteristics of the interaction between emotion and inhibition, event-related potentials (ERPs) were measured as participants (N=30) performed a modified version of the Go/Nogo task that required the inhibition of prepotent responses to neutral cues during three different emotional contexts: negative, neutral, and positive. Temporal and spatial principal component analyses were employed to detect and quantify, in a reliable manner, those ERP components related to response inhibition (i.e., Nogo-N2 and Nogo-P3), and a source-localization technique (sLORETA) provided information on their neural origin. Behavioral analyses revealed that reaction times (RTs) to Go cues were shorter during the positive context than during neutral and negative contexts. ERP analyses showed that suppressing responses to Nogo cues within the positive context elicited larger frontocentral Nogo-P3 amplitudes and enhanced anterior cingulate cortex (ACC) activation than within the negative context. Regression analyses revealed that Nogo-P3 (i) was inversely related to RTs, supporting its association with the inhibition of a prepotent response, and (ii) was associated with contextual valence (amplitude increased as context valence was more positive), but not with contextual arousal. These results suggest that withholding a prepotent response within positively valenced contexts is more difficult and requires more inhibitory control than within negatively valenced contexts.