How electrical brain stimulation can change the way we think

U.S. military researchers have had great success using “transcranial direct current stimulation” (tDCS) — in which they hook you up to what’s essentially a 9-volt battery and let the current flow through your brain. After a few years of lab testing, they’ve found that tDCS can more than double the rate at which people learn a wide range of tasks, such as object recognition, math skills, and marksmanship.
We don’t yet have a commercially available “thinking cap,” but we will soon. So the research community has begun to ask: What are the ethics of battery-operated cognitive enhancement? Recently, a group of Oxford neuroscientists released a cautionary statement about the ethics of brain boosting; then the U.K.’s Royal Society released a report that questioned the use of tDCS for military applications.