Neural circuit mapping of waiting impulsivity and proactive inhibition with convergent evidence from fMRI and TMS

Introduction Waiting and stopping are essential distinct elements of appropriate behavioral control with its dysfunction implicated in various impulsivity related mental disorders. Although rodent human studies have investigated both phenomena, the role preparing to stop waiting has rarely been investigated. Furthermore, convergent evidence from multi-modal investigation tools remains a poorly utilized approach addressing such questions. Objectives Here, we conducted two separate, but hierarchical studies, using functional magnetic resonance imaging (fMRI) map neural circuit involved proactive stopping, subsequently provide mechanistic causal disruption this by transcranial stimulation (TMS). In second study, based on our fMRI study data, attempted investigate possible causation between LIFG modulating LIFG, i.e. non-invasively producing “virtual lesion” an inhibitory (TMS) protocol called continuous theta burst Methods We recruited 41 healthy volunteers who performed adapted version (1CSRT) well-established 5 choice serial reaction time task capture impulsivity. developed novel measuring inhibition. scanned participants while completing these tasks. Our data showed strong association activity 1CSRT task. single-blind, randomized, between-subjects design cTBS sample 51 completed (2CSRT task). priori hypothesis was that would transiently decrease local cortical increase frequency premature responses fixed delayed cue-target interval trials 2CSRT Results first show shared network comprising pre-supplementary motor area bilateral anterior insula underlying stopping. further demonstrate dorsomedial prefrontal cortex left inferior frontal gyrus (LIFG) negatively correlated additional target onset delay. active significantly increased Conclusions validated significance structure for assessing aspects impulsivity, which is translational interest. established lIFG thus highlighting integrity circuitry required Disclosure Interest None Declared