Motor inhibition processes in Go/No-Go and Stop Signal Tasks: New insight from mouse tracking

Action control can be guided by visual stimuli, particularly in situations with stringent time/accuracy constraints as in certain sports. Action implementation and inhibition in response to visual targets have been studied in relation to proactive and reactive cognitive control. In those studies, performance is typically recorded by keypress methods that could be insufficient to capture dynamic response features. We used a mouse-tracking procedure to evaluate movement velocity profiles related to proactive and reactive control during two inhibitory visuomotor tasks. Participants performed a cued Go/No-Go (cGNG), with high&low Go-stimulus occurrence conditions, which mainly involve proactive control; and a Stop Signal Task (SST), where the reactive component is engaged. We hypothesized that different movement profiles could be associated with inhibitory failures between tasks, reflecting the influence of proactive/reactive mechanisms on motor preparation and execution. Set-up consisted of a mouse-device positioned in the centre of a board. For Go-conditions, subjects were instructed to move the mouse quickly and accurately in the direction indicated by the Go-stimulus (i.e., left/right) until reached a set barrier. For No-Go/Stop conditions they were requested not to move the mouse. Movements with a smooth profile without corrections were classified as 'one-shot'. Multi-peaked profiles, reflecting movement alterations, were classified as 'non-one-shot'. A significantly higher proportion of one-shots was found in the SST (81±9%) compared to the cGNG (high:21±34%, low:30±33%) for inhibition failures (p<0.001). No difference emerged between tasks for Go-conditions. Profiles revealed that inhibitory failures are differently modulated under mainly reactive/proactive control: corrections to the initial motor plan were less frequent under mainly reactive control, suggesting that the influence of inhibitory control mechanisms on motor planning may be marginal. The opposite trend emerged for mainly proactive control. Additionally to these findings, a preliminary comparison between professional athletes and non-athletes is reported to address whether and how experience plays a role.