Intertrial interval duration affects error monitoring

The purpose of this study was to investigate the effect of varying intertrial interval (ITI) durations on neural signals of error monitoring, given the importance of the ITI as a time window for engaging in self-evaluation and cognitive control. In a between-subjects design, 35 participants were assigned to one of three ITI durations (short: 768 ms; medium: 1,280 ms; long: 1,792 ms) in a standard Stroop task while EEG was recorded. Participants in the short-ITI group demonstrated lower performance accuracy, a reduced error-related negativity (even when correcting for frequency of errors), lower error-related alpha suppression during the ITI, and increased post-error slowing. Results indicate that fast-paced trial timing can be disruptive to self-monitoring, perhaps due to capacity limitations or bottlenecks in processing.