The physiological basis of transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) is the noninvasive method of choice for studying the causal relevance of a cortical area in the human brain. The success of TMS, however, is contrasted by limited insight into its mechanism of action. A recent study by Allen and colleagues offers stunning new insight into the physiological underpinnings of TMS. Their findings expand our understanding about a method that is widely used for stimulating research in the cognitive neurosciences.