The students were referred to Yousef Salimpour, a Johns Hopkins Medicine postdoctoral research associate who has been studying a noninvasive Parkinson’s therapy called transcranial direct current stimulation. In this painless treatment, low-level current is passed through two electrodes placed over the head to tweak the electrical activity in specific areas of the brain. The technique can be used to excite or inhibit these nerve cells. The treatment is still considered experimental, but it has attracted much attention because it does not require surgery and is inexpensive, safe and relatively easy to administer without any side effects.

Source: https://hub.jhu.edu/2015/06/10/stimband-brain-stimulator