David Noonan in Smithsonian:
Two hundred and thirty-five years after the Italian scientist Luigi Galvani reported that dismembered frog legs twitch in response to a static charge applied to a nerve, we are still exploring the mysteries of what he called “animal electricity,” especially in the brain. That the brain generates a bit of its own electricity, which can be detected by an electroencephalogram, or EEG, is well established, as is the fact that some neurosurgeons today sometimes use hair-thin electrodes to stimulate deep brain structures and stop Parkinson’s tremors. But scientists are now exploring a question that is, well, mind-boggling: Can low-voltage doses of electricity, transmitted through hair, skin and skull directly into particular regions of the brain, make already healthy people sharper and more alert?
Aron Barbey, a 39-year-old neuroscientist at the University of Illinois, is a leader in this research, though he is excruciatingly cautious about its prospects. He resists the idea that tomorrow’s malls and airports will feature commercial brain-charging stations, updated versions of today’s massage stops, but if that future (or something like it) comes to pass, his work will have played a critical role in bringing it about. Barbey is the director of the UI’s Decision Neuroscience Laboratory at the university’s Beckman Institute for Advanced Science and Technology, and his experiments appear to point to a time when students, soldiers, executives and the elderly could all benefit from a treatment called transcranial direct-current stimulation (tDCS).