Specific modulation of intracortical excitability by anodal tDCS applied over the primary motor cortex during motor skill acquisition

Introduction: We recently demonstrated that anodal tDCS applied to the primary motor cortex (M1) facilitates motor skill acquisition over multiple days through an effect on consolidation (1). Here we investigated the neurophysiological correlates of this effect using transcranial magnetic stimulation (TMS). Methods: 24 healthy subjects trained their dominant right hand on a sequential isometric pinch force task (200 trials/day) for 5 days. They received either sham tDCS or anodal tDCS (20min 1mA, 0.048 C/cm2, total charge 0.04 mA/cm2) to the left M1 during training. Motor cortical function, including motor thres…