Transcranial magnetic stimulation as a tool for cognitive studies

Transcranial Magnetic Stimulation (TMS) is a tool for the non-invasive stim ulation of the human brain. It allows the activation of arbitrary sites of the superficial cortex and, combined with other brain-imaging techniques su ch as EEG, PET, and fMRI, it can be used to evaluate cortical excitability and connectivity. This is of major importance in, for example, the study of cognitive processes such as language, learning, memory and self-representa tion, which are thought to be represented in multiple brain areas. The mech anisms of action of TMS are known on a basic level, but its effect on the a ctivation stale of brain tissue is still poorly understood. Clinical applic ations of TMS have also been proposed and guidelines for its safe use draft ed.