PreSMA stimulation changes task‐free functional connectivity in the fronto‐basal‐ganglia that correlates with response inhibition efficiency

Abstract

Previous work using transcranial magnetic stimulation (TMS) demonstrated that the right pre-supplementary motor area (preSMA), a node in the fronto-basal-ganglia network, is critical for response inhibition. However, TMS influences interconnected regions, raising the possibility of a link between the preSMA activity and the functional connectivity within the network. To understand this relationship, we applied single-pulse TMS to the right preSMA during functional magnetic resonance imaging when the subjects were at rest to examine changes in neural activity and functional connectivity within the network in relation to the efficiency of response inhibition evaluated with a stop-signal task. The results showed that preSMA-TMS increased activation in the right inferior-frontal cortex (rIFC) and basal ganglia and modulated their task-free functional connectivity. Both the TMS-induced changes in the basal-ganglia activation and the functional connectivity between rIFC and left striatum, and of the overall network correlated with the efficiency of response inhibition and with the white-matter microstructure along the preSMA – rIFC pathway. These results suggest that the task-free functional and structural connectivity between the rIFCop and basal ganglia are critical to the efficiency of response inhibition.

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].…”

“…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]. Greater pre-SMA activation has been associated with: (i) faster SSRTs [6], and (ii) stronger effective connectivity with the right caudate [40] and right IFG [37], related to gray matter densities [41]. Our results showing that continuous cTBS of the pre-SMA improves/speeds up motor inhibition is consistent with previous findings [6].…”

On the Globality of Motor Suppression: Unexpected Events and Their Influence on Behavior and Cognition

“…Early monkey tract tracing showed that likely homologues of these prefrontal areas connect to the STN (Inase et al, 1999) (Nambu et al, 1997) (also see Haynes and Haber, 2013). Several human studies using diffusion tensor imaging have also reported such connections, and some have shown that white matter variability in these connections relates to the speed of stopping (Aron et al, 2007; Coxon et al, 2012; Danielmeier et al, 2011; Forstmann et al, 2012; Rae et al, 2015a; Xu et al, 2016). These specific connections provide an anatomical basis for a putative ‘hyperdirect pathway’ by which the STN can be quickly activated (Nambu et al, 2002).…”

Using subjective expectations to model the neural underpinnings of proactive inhibition

“…In addition to the striatum, the right inferior frontal gyrus (IFG) has long been recognized as playing an important role in proactive inhibition (Aron, Fletcher, Bullmore, Sahakian, & Robbins, 2003;Rubia, Smith, Brammer, & Taylor, 2003;Vink, de Leeuw, et al, 2015;Vink, Kaldewaij, et al, 2015). An increase in functional connectivity between this area and the basal ganglia has been shown to increase response inhibition efficiency (Xu et al, 2016) and rIFG activity has been correlated with stopping speed (Whelan et al, 2012). In contrast, hypoactivation of the rIFG in patients with ADHD has been linked to impaired response inhibition (Morein-Zamir et al, 2014).…”