Magnetic fields that map the brain may also treat its disorders

Welcome to transcranial magnetic stimulation (TMS), one of the hottest research tools in neuroscience. Since its invention 15 years ago, TMS has become a relatively simple, noninvasive, and usually painless way to electrically stimulate specific brain regions. It's power tantalizes investigators who want to unravel how the human mind works. More recently, TMS has also grabbed the attention of physicians and psychologists, who predict that it has the potential to treat conditions ranging from epilepsy to stuttering to depression.

There's preliminary evidence, for example, that TMS offers a less drastic alternative to electroconvulsive therapy (ECT), the treatment of last resort for people with severe depression. At the same time, investigators acknowledge that there's much they don't know about how TMS affects the brain.