Abstract #40: Direction of PAS-Induced Modulation of Corticospinal Excitability Depends on Timing Between Stimulation and Movement Onset

Abstract

Introduction: Paired associative stimulation (PAS) is a recognized technique to induce neuro-plastic changes in the human motor cortex (M1). PAS modulates cortical excitability by pairing peripheral nerve stimulation with transcranial magnetic stimulation (TMS) of M1 in a timing-dependent manner to induce Hebbian-like plasticity. To date, PAS is most often performed with the subject at rest. A key question about how to combine PAS and voluntary movement is the timing of stimuli with respect to muscle activation onset. Here, we investigated the effect of PAS on M1 excitability when the stimuli are delivered during preparation or execution of a voluntary movement.