The motor threshold (MT) for the left abductor pollicis brevis will be determined by a figure of 8 shaped coil, using the Rossini-Rothwell method. MT will be defined as the lowest intensity, which produces 5 motor evoked potential (MEP) responses of at least 50 µV in 10 trials. The prefrontal cortex rTMS stimulation site will be determined by measuring 5 cm anterior and in a parasagittal line from the point of maximum stimulation of left abductor pollicis muscle. Ten active rTMS treatments will be administered at 10 Hz frequency, over right or left prefrontal cortex at 110% of MT for duration of 5 seconds and 20 trains per session, with the coil-angled tangentially to the head.