ABSTRACT
Transcranial magnetic stimulation (TMS) is a technique to stimulate the human brain transcranially by pulsed magnetic fields generated by a coil positioned outside the head. The pulsed magnetic fields induce electric fields in the brain, and the induced electric fields stimulate the brain. Stimulation of human brain by TMS with a round coil was reported by Barker et al. (1985). The success of the human brain stimulation by TMS made a strong impact on the scientific community. By TMS with a round coil, however, it was difficult to stimulate a localized area of the brain. A method of localized brain stimulation by TMS with a figure-eight coil was proposed by Ueno et al. (1988), and stimulation of the human motor cortex within a 5 mm resolution was successfully realized (Ueno et al., 1989). The functional map of the human motor cortex was obtained in a 5 mm resolution by this method (Ueno et al., 1990). TMS with a figure-eight coil is now used worldwide in cognitive brain research and clinical medicine.
