At the National Institute for Neurological Disorders and Stroke in Bethesda, Maryland scientists are studying the effect an electric current applied to the scalp has on cognitive abilities of the subject.
From MIT Technology Review:
To explore how effective such stimulation can be as a learning tool, Eric Wassermann, a neuroscientist at the National Institute for Neurological Disorders and Stroke, is using an approach known as transcranial direct current stimulation (TDCS), in which an electrical current is passed directly to the brain through the scalp and skull. The technology for TDCS, which has been available for decades, is simple and fairly crude. (In the 1960s, it was used to improve mood in people with psychiatric disorders, although that effect hasn’t been repeated in more recent studies.) And in contrast to people undergoing electroconvulsive therapy, a seizure-inducing treatment used for severe depression that requires anesthesia, people undergoing TDCS feel just a slight tingle, if anything.
The device is simple: a nine-volt battery that’s been approved by the Food and Drug Administration for delivering drugs across the skin is connected to large flat sponges that are moistened and then applied to the head. It delivers a gentle 2 to 2.5 milliamps of current spread over a 20 to 50 square millimeter area of the scalp for up to 15 minutes. Little of that current actually reaches the brain–about half is shunted away from the target area, and the other half quickly dissipates as it gets farther from the scalp.
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