Timing-specific associative plasticity between supplementary motor area and primary motor cortex in humans

Introduction: The supplementary motor area (SMA) is essential for preparation and execution of voluntary movements. Anatomically, SMA shows dense reciprocal connections to primary motor cortex (M1), yet the functional connectivity within the SMA-M1 network is not well understood. Here we modulated the SMA-M1 network using multifocal transcranial magnetic stimulation (TMS) and detected changes in functional coupling by electroencephalography (EEG) as well as corticospinal output changes by motor evoked potentials (MEPs). Material and Methods: Twenty-four right-handed subjects aged 19–43 years participated in the…