Simultaneous EEG and pupillary evidence for post-error arousal during a speeded performance task.

Arousal evoked by detecting a performance error may provide a mechanism by which error detection leads to either adaptive or maladaptive changes in attention and performance. By pairing EEG data acquisition with simultaneous measurements of pupil diameter, which is thought to reflect norepinephrinergic arousal, this study tested whether transient changes in EEG oscillations in the alpha frequency range (8-12 Hz) following performance mistakes may reflect error-evoked arousal. In the inter-trial interval following performance mistakes (approximately 8% of trials), pupil diameter increased and EEG alpha power decreased, compared to the inter-trial interval following correct responses.