According to the advertising hype, you too can enjoy incredible neural and psychological benefits in the comfort of your own home by using a simple electrical device that offers transcranial direct current stimulation (tDCS). For instance, three different models of tDCS devices sold online claim to improve mood, increase creativity, enhance memory, accelerate learning, and combat pain and depression. For the low, low price of between $99 and $189.95, you get a compact handheld device with easy-to-use controls and two electrical leads that end in small sponges. These sponges are dipped into saline solution to make them current-carrying electrodes, then placed against your head. The websites typically show the sponges located on either side of the forehead, but point out that they need to be placed elsewhere on the skull to activate different parts of the brain, depending on the desired outcome.
Wherever you place the sponges, when you switch on the unit, you’re pumping electric current into your brain, although not very much.