Adventures in transcranial direct-current stimulation

150406_r26337-320Elif Batuman at The New Yorker:

The human drive to zap one’s head with electricity goes back at least to antiquity, and was originally satisfied by means of electric fish. “Headache even if it is chronic and unbearable is taken away and remedied forever by a live torpedo placed under the spot that is in pain,” the first-century physician Scribonius Largus wrote. He also used the torpedo, a species of ray native to the Mediterranean, to treat hemorrhoids. In the eleventh century, the Islamic polymath Avicenna reportedly recommended the placement of an electric catfish on the brow to counteract epilepsy. As late as 1762, a Dutch colonist in Guyana wrote that “when a slave complains of a bad headache” he should put one hand on his head and another on a South American electric eel and “will be helped immediately, without exception.”

The invention, in 1745, of the Leyden jar—a device to store static electricity—enabled many new experiments in electrotherapy, not all of them deliberate. In 1783, Jan Ingenhousz, a Dutch scientist, accidentally picked up a charged Leyden jar, causing an explosion that made him temporarily lose his memory, judgment, and ability to read and write. Having found his way home with great difficulty, he went to sleep. He woke to find that his mental faculties had not only returned but had sharpened: “I saw much clearer the difficulties of every thing,” he wrote in a letter to Benjamin Franklin. “What did formerly seem to me difficult to comprehend, was now become of an easy solution.”

more here.