Devices that send a weak electrical current through your brain via head-mounted electrodes are marketed online as cognitive enhancers. Transcranial Direct Current Stimulation (tDCS) – not to be confused with Transcranial Magnetic Stimulation (TMS) – is claimed by those who sell it to speed up reactions, calm you down, help you focus, increase physical endurance and improve more or less any mental skill you want.
Although it sounds gimmicky, there is actually a vast amount of solid evidential support for tDCS both as a treatment (for pain, depression, tinnitus, dementia and much else) and for enhancement. When it’s used correctly it is extraordinarily safe, and comparatively cheap – you can get a tDCS kit for about $127.
However, like brain training, tDCS has not yet shown itself capable of improving overall cognition (rather than individual functions), and much of what’s known about it has come from a large, dedicated band of DIY researchers, and as a result is anecdotal and/or difficult to assess. Judge the evidence for yourself at reddit.com/r/tDCS/.ß
Rita Carter is a science writer, lecturer and broadcaster, specialising in the brain
Devices that use tDCS (transcranial Direct Current Stimulation) to ‘boost your brain’ are widely available, though scientific evidence that they do so is hard to find