Transcranial magnetic stimulation (TMS) is a noninvasive method used to stimulate small regions of the brain. During a TMS procedure, a magnetic field generator, or "coil", is placed near the head of the person receiving the treatment. The coil produces small electric currents in the region of the brain just under the coil via electromagnetic induction. The coil is connected to a pulse generator, or stimulator, that delivers electric current to the coil.