Common and Unique Neurophysiological Processes That Support the Stopping and Revising of Actions.

Abstract

Inhibitory control is a crucial cognitive-control ability for behavioral flexibility, which has been extensively investigated through action-stopping tasks. Multiple neurophysiological features have been proposed as "signatures" of inhibitory control during action-stopping, though the processes indexed by these signatures are still controversially discussed. The present study aimed to disentangle these processes by comparing simple stopping situations with those in which additional action revisions were needed. Three experiments in female and male humans were performed to characterize the neurophysiological dynamics involved in action-stopping and action-changing, with hypotheses derived from recently developed two-stage "pause-then-cancel" models of inhibitory control. Both stopping and revising an action triggered an early, broad "pause"-process, marked by frontal EEG β-frequency bursting and nonselective suppression of corticospinal excitability. However, EMG showed that motor activity was only partially inhibited by this "pause" and that this activity could be modulated during action revision. In line with two-stage models of inhibitory control, subsequent frontocentral EEG activity after this initial "pause" selectively scaled depending on the required action revisions, with more activity observed for more complex revisions. This demonstrates the presence of a selective, effector-specific "retune" phase as the second process involved in action-stopping and action revision. Together, these findings show that inhibitory control is implemented over an extended period of time and in at least two phases. We are further able to align the most commonly proposed neurophysiological signatures to these phases and show that they are differentially modulated by the complexity of action revision.