A Proactive Mechanism for Selective Suppression of Response Tendencies

Abstract

While most research on stopping action examines how an initiated response is stopped when a signal occurs (i.e. reactively), everyday life also calls for a mechanism to prepare to stop a particular response tendency (i.e. proactively and selectively). We hypothesized that human subjects can prepare to stop a particular response by proactively suppressing that response representation in the brain. We tested this by using single pulse Transcranial Magnetic Stimulation and concurrent electromyography. This allowed us to interrogate the corticomotor excitability of specific response representations even before action ensued. We found that the motor-evoked potential (MEP) of the effector that might need to be stopped in the future was significantly reduced compared to when that effector was at rest. Further, this neural index of proactive and selective suppression predicted the subsequent selectivity with which the behavioral response was stopped. These results go further than earlier reports of reduced motor excitability when responses are stopped. They show that the control can be applied in advance (proactively) and also targeted at a particular response channel (selectively). This provides novel evidence for an active mechanism for suppression in the brain that is setup according to the subject's goals and even before action ensues.

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

“…Aron and Verbruggen, 2008;Claffey et al, 2010;Greenhouse et al, 2012;Majid et al, 2012). These data indicate that specific inhibition mechanisms support selective inhibition only when the need for selective inhibition can be predicted (Cai et al, 2011). By contrast, while our results largely support the current "global stopping plus movement re-initiation" model of reactive selective inhibition, they extend this Combination model by suggesting that the inhibition mechanism may differ during its very early phase when global or selective inhibition is required in unpredictable conditions.…”

Theta burst magnetic stimulation over the pre-supplementary motor area improves motor inhibition

“…Amongst the various processes by which the pre-SMA is considered to exert top-down control [34][35][36][37], our results suggest a predominant role in reactive motor inhibition, without a significant contribution to conflict resolution (see next section for interpretation). Previous imaging evidence shows activation of the pre-SMA during performance of the go no-go [38,39], or stop signal tasks [3][4][5]7,9,21].…”

Proactive modulation of long-interval intracortical inhibition during response inhibition

“…Transcranial magnetic stimulation (TMS) has been used to assess the temporal modulation of corticomotor excitability (CME) during both types of response inhibition. Proactive stopping is suggested to recruit the indirect basal ganglia pathway to selectively decrease CME for only the movement cued to stop (Aron and Verbruggen 2008;Cai et al 2011;Majid et al 2013). A topic of current debate is whether reactive stopping can be achieved selectively (Xu et al 2015), given that several lines of evidence indicate a transient process in which stopping response preparation suppresses movement nonselectively.…”