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

Abstract Background Stopping an ongoing motor response or resolving conflict induced by conflicting stimuli are associated with activation of a right-lateralized network of inferior frontal gyrus (IFG), pre-supplementary motor area (pre-SMA) and subthalamic nucleus (STN). However, the roles of the right IFG and pre-SMA in stopping a movement and in conflict resolution remain unclear. We used continuous theta burst stimulation (cTBS) to examine the involvement of the right IFG and pre-SMA in inhibition and conflict resolution using the conditional stop signal task. Methods We measured stop signal reaction time (SSRT, measure of reactive inhibition), response delay effect (RDE, measure of proactive action restraint) and conflict induced slowing (CIS, measure of conflict resolution). Results Stimulation over the pre-SMA resulted in significantly shorter SSRTs (improved inhibition) compared to sham cTBS. This effect was not observed for CIS, RDE, or any other measures. cTBS over the right IFG had no effect on SSRT, CIS, RDE or on any other measure. Conclusions The improvement of SSRT with cTBS over the pre-SMA suggests its critical contribution to stopping ongoing movements.