Differences between 3 Hz monophasic and biphasic repetitive transcranial magnetic stimulation

These findings suggest that the facilitation occurred at the motor cortex. We hypothesize that monophasic TMS has a stronger short-term effect during repetitive stimulation than biphasic TMS because monophasic pulses preferentially activate one population of neurons oriented in the same direction so that their effects readily summate. Biphasic pulses in contrast may activate several different populations of neurons so that summation of the effects is not so clear as with monophasic pulses.