Early attentional processes distinguish selective from global motor inhibitory control: an electrical neuroimaging study

The rapid stopping of specific parts of movements is frequently required in daily life. Yet, whether selective inhibitory control of movements is mediated by a specific neural pathway or by the combination between a global stopping of all ongoing motor activity followed by the re-initiation of task-relevant movements remains unclear. To address this question, we analyzed electrical neuroimaging responses to global vs selective inhibition stimuli presented during a Go/NoGo task. Participants had to respond as fast as possible with their two hands to Go stimuli and to withhold the response from the two hands (global inhibition conditions, GNG) or from only one hand (selective inhibition, SNG) when specific NoGo stimuli were presented. Behaviorally, we replicated previous evidence for slower response times in the SNG than in the Go condition. Electrophysiologically, there were two distinct phases of event-related potentials modulations between the GNG and the SNG conditions. At 110-150ms post-stimulus onset, there was a difference in the strength of the electric field without concomitant topographic modulation, indicating the differential engagement of statistically indistinguishable configurations of neural generators for selective and global inhibitory control. At 150-200ms, there was a change in the electric field topography, indicating the engagement of distinct configurations of neural generators. Source estimations localized these effects within bilateral temporo-occipital and posterior parietal regions and within a parieto-central network, respectively. Our results suggest that while both types of motor inhibitory control depend on global stopping mechanisms, selective and global inhibition still differ quantitatively at early attention-related processing phases