Researchers at the National Institute for Neurological Disorders and Stroke are studying how applying gentle electrical current to the scalp can improve learning.

The transcranial direct current stimulation (TDCS) device uses a simple nine-volt battery, which passes about 2 to 2.5 milliamps of electrical current directly to the brain through the scalp and skull.

Researchers found that direct current stimulation could improve memory in participants asked to learn and then recall a list of 12 words.