Researchers are studying whether stimulating the brain before rehabilitation could yield greater gains in motor function for people recovering from stroke. The technology is akin to a more advanced version of constraint-induced therapy in which clinicians physically tie down a patient's good arm, which forces the patient to use the injured side. With this non-invasive device, researchers are using electromagnetism to slow activity in portions of the healthy brain hemisphere that control the uninjured arm, similarly forcing the brain to use its injured half.