Emotional enhancement of error detection : the role of perceptual processing and inhibition monitoring in failed auditory stop trials

The first aim of the present study was to test whether arousing, aversive sounds can influence inhibitory task performance and lead to increased error monitoring relative to a neutral task condition. The second aim was to examine whether the enhancement of error monitoring in an affective context (if present) could be predicted from stop-signal-related brain activity. Participants performed an emotional stop-signal task that required response inhibition to aversive and neutral auditory stimuli. The behavioral data revealed that unpleasant sounds facilitated inhibitory processing by decreasing the stop-signal reaction time and increasing the inhibitory rate relative to neutral tones. Aversive sounds evoked larger N1, P3, and Pe components, indicating improvements in perceptual processing, inhibition, and conscious error monitoring. A first regression analysis, conducted regardless of the category of the stop signal, revealed that both selected indexes of stop-signal-related brain activity - the N1 and P3 amplitudes recorded in the unsuccessfully inhibited trials - significantly accounted for the Pe component variance, explaining a large amount of the observed variation (66%). A second regression model, focused on difference measures (emotional minus neutral), revealed that the affective increase in the P3 amplitude on failed stop trials was the only factor that significantly accounted for the emotional enhancement effect in the Pe amplitude. This suggests that, in general (regardless of stop - signal condition), error processing is stronger if the erroneous response directly follows the stimulus, which was effectively processed on both the perceptual and action - monitoring levels. However, only inhibition - monitoring evidence accounts for the emotional increase in conscious error detection.