Stopping a response has global or nonglobal effects on the motor system depending on preparation

Abstract

Much research has focused on how people stop initiated response tendencies when instructed by a signal. Stopping of this kind appears to have global effects on the motor system. For example, by delivering transcranial magnetic stimulation (TMS) over the leg area of the primary motor cortex, it is possible to detect suppression in the leg when the hand is being stopped (Badry R et al. Suppression of human cortico-motoneuronal excitability during the stop-signal task. Clin Neurophysiol 120: 1717-1723, 2009). Here, we asked if such "global suppression" can be observed proactively, i.e., when people anticipate they might have to stop. We used a conditional stop signal task, which allows the measurement of both an "anticipation phase" (i.e., where proactive control is applied) and a "stopping" phase. TMS was delivered during the anticipation phase (experiment 1) and also during the stopping phase (experiments 1 and 2) to measure leg excitability. During the anticipation phase, we did not observe leg suppression, but we did during the stopping phase, consistent with Badry et al. (2009). Moreover, when we split the subject groups into those who slowed down behaviorally (i.e., exercised proactive control) and those who did not, we found that subjects who slowed did not show leg suppression when they stopped, whereas those who did not slow did show leg suppression when they stopped. These results suggest that if subjects prepare to stop, then they do so without global effects on the motor system. Thus, preparation allows them to stop more selectively.

Proactive modulation of long-interval intracortical inhibition during response inhibition

“…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. For example, when successful stopping can be achieved by inhibiting all movement, CME is reduced in response-irrelevant muscles (Badry et al 2009;Cai et al 2012;Coxon et al 2006;Greenhouse et al 2012). When only a subcomponent of a prepared response is required to stop (Partial trials), the remaining response is delayed (Coxon et al 2007(Coxon et al , 2009(Coxon et al , 2012MacDonald et al 2012MacDonald et al , 2014.…”

The influence of recent decisions on future goal selection

“…These parameters yield a measure of the reactive response to stop signal presentation, which is also referred to as the stop signal reaction time (SSRT). A well-described effect of proactive control in this task is the elongation of the RT in go trials following trials with stop signal presentation [30], which corresponds to an increased probability of success in case of a further stop trial appearance [28,31]. The observation that a recent trial sequence can influence performance in the countermanding task suggests that factors other than the outcome of the two competitive processes in the race might play a role [27,29,30,[32][33][34][35][36].…”

The role of the right presupplementary motor area in stopping action: two studies with event-related transcranial magnetic stimulation

“…A distinction between standard (nonselective) and selective stopping has recently been made on the basis of behavioral and physiological studies (Aron and Verbruggen 2008;Greenhouse et al 2012;Majid et al 2011). The standard (nonselective) form of stopping is putatively implemented via the hyperdirect pathway to the subthalamic nucleus of the basal ganglia (Aron et al 2007b;Forstmann et al 2012;Jahfari et al 2011;Ray et al 2012), whereas the selective stopping could be implemented by the indirect pathway through the striatum.…”