EDITORIAL Integrating TMS with EEG: How and What For?

Transcranial magnetic stimulation (TMS) is a unique tool that utilizes magnetic fluxes to noninvasively stimulate the human cortex. Introduced in 1985 (Barker et al. 1985), it has developed into a powerful research device by virtue of its capacity to stimulate the brain with a relatively good spatial and temporal selectivity (Walsh and Cowey 2000), without the pain associated with transcranial electrical stimulation (TES), and with an excellent safety profile if appropriate guidelines are followed (Rossi et al. 2009). Guided by studies using brain imaging (e.g. functional MRI) that deliver evidence correlating brain activity with specific behaviors, TMS has been employed to induce transient ‘‘virtual lesions’ ’ in humans under controlled conditions, providing causal evidence linking activity in specific brain areas with behavior (Walsh and Pascual