Theta Burst Stimulation (TBS) is a type of sub-threshold repetitive Transcranial Magnetic Stimulation (rTMS) which has effects on the excitability of human motor cortex that outlast stimulation by up to an hour. TBS also affects performance of a motor task for up to 30 minutes after stimulation in healthy subjects, and improves reaction times (and increases corticospinal excitability) in patients with chronic stroke (Talelli 2005). The advantages of TBS over other non-invasive brain stimulation strategies are its low intensity, short duration of application and long lasting effects.