When patients with severe depression don't respond to medication, they are often prescribed electroconvulsive therapy, or ECT, in which an electric shock is used to simulate activity in the prefrontal cortex -- frequently easing their symptoms. It's effective, but it has significant side effects. The reason is that there is no way to confine the current to the prefrontal cortex. The electricity, delivered to the skin, floods the entire brain, stimulating areas that trigger se