Calls to regulate electrical brain stimulation
Early research suggests that using electrical currents to stimulate your brain could improve your attention and maths ability.
It could also help alleviate symptoms of depression and Parkinson's disease.
But now similar devices (like the one shown in this clip) are sold online and marketed specifically to gamers, which has led for calls to regulate the technology.
Dr Hannah Maslen from the Oxford Martin School at the University of Oxford, explains what electrical stimulation can do and why her team wants regulation.
Read more: Warning over electrical brain stimulation
Video Journalist: Dave O'Neill