Associations between interhemispheric inhibition, measured by the ipsilateral silent period (iSP), and overall motor impairment of the arm (measured by the Upper Extremity Fugl-Meyer Assessment) and proximal arm motor performance (measured by reaching response time). Note that response time values are displayed longest to shortest (left to right), since longer response time indicates slower task completion. For both biceps and triceps, higher iSPs correlated with more severe motor impairment of the arm (top row). For triceps, higher iSP values also tended to be associated with longer (i.e. slower) reaching response times (bottom right).