I called Weisend recently to see what he thought of people experimenting with tDCS. “In the DIY crowd they don’t have the neuroimaging to start the process and know where to place the electrodes,” he told me. “Their success and their safety are going to be limited.” In the laboratory, subjects go through two or three sessions of tDCS over a week. What happens long term if you do more than that? Nobody knows. And the equipment you order from some random person online may not be as reliable as what’s used in a laboratory.
That said, Weisend believes tDCS can be done safely, and he thinks it might be used to prevent memory loss in the elderly or to help patients recover from traumatic brain injuries. He’s tried tDCS on his own brain hundreds of time and hasn’t suffered any deleterious effects—with the notable exception of a few skin burns that were severe enough to leave scars. “You get attached to your work, I guess,” he says.