ABSTRACT
Transcranial magnetic stimulation (TMS) is a noninvasive technique used to apply brief magnetic pulses to the brain. The pulses are administered by passing high currents through an electromagnetic coil placed upon the scalp that can induce electrical currents in the underlying cortical tissue, thereby producing a localized axonal depolarization. Neuronal stimulation by TMS was first demonstrated in 1985 (Barker et al., 1985), when a circular coil was placed over a normal subject vertex and evoked action potentials from the abductor digiti minimi. Since then this technique has been applied to studying nerve conduction, excitability, and conductivity in the brain and peripheral nerves, and to studying and treating various neurobehavioral disorders, primarily mood disorders (Kircaldie et al., 1997; Wassermann and Lisanby, 2001).
