Transcranial Direct-Current Stimulation is a technique that involves passing low-level electrical currents through parts of the brain. The effects of this are various, depending somewhat on the area being zapped, but it appears to change the baseline level of cortical excitability, and the effects can persist for several hours (or perhaps days) after a standard 20-minute session. People have been zapping themselves in the head pretty much since electricity was discovered, but tDCS in its modern form is a relatively new technique, and is thought to have potential for treating depression, stroke-recovery, and other clinical issues. It can also apparently lead to enhancements of normal functions (visual, motor, working memory, etc.) in healthy participants. The Guardian published an article this week on the effects of tDCS on maths ability, based on research which has been fairly widely criticised on Twitter.
This potential cognitive-enhancing effect is what’s caught the eye of a company called Foc.us, who are now offering a commercial tDCS system, for use by anyone at home, for $249 (or £179 in the UK). Here it is:
So, it’s a small band with a battery at the back, and four electrodes at the front that sit over the forehead. Foc.us are marketing this as a device for gamers to “Excite your prefrontal cortex and get the edge in online gaming.”
So – does it work? Possibly… But it almost certainly doesn’t do what the company says it does. For a start, if you want to “get the edge in online gaming” wouldn’t you want to stimulate your motor cortex (at the top of the head) and/or the visual cortex (at the back)? It’s unclear how stimulating the prefrontal cortex (behind the forehead) would give you an advantage in games. In fact, (as this article explains) placement of the electrodes over the dorsolateral prefrontal cortex is most often used for treatment of depression and chronic pain, so potentially these devices might have more of an effect on mood or emotions than any useful gaming-related functions. There is no information about effectiveness or effects on the company website; the standard protocol of 1mA stimulation for five minutes is unlikely to do much beyond delivering a mild sensation on the scalp. The device can be configured to deliver up to 2mA (through a smartphone app), which may be enough to affect the brain.
Furthermore, there are important safety considerations for this kind of device. In fact, tDCS is such a recent technique that researchers are still in the process of working out what the safe limits actually are (in terms of both power delivered, and duration/frequency of stimulation). This article highlights the possibility that the electrodes can cause skin lesions, and tDCS can even potentially cause lesions in the brain (admittedly in rats, and with currents a couple of orders of magnitude higher than used in humans). Still, potentially people could be using these systems repeatedly for long periods, and we have very little idea about what the effects of that might be.
If you’re still really intent on zapping your own brain to see if you can become an intellectual giant, or give yourself telekinetic powers or X-ray vision (hint: you won’t) then you could also build your own tDCS device using a 9V battery, some wire, a resistor and a couple of sponges, as described here. Total cost: about $5.
ABSOLUTELY DO NOT DO THIS. IT’S A FUCKING STUPID THING TO DO TO YOURSELF.
Passing electrical currents through the body can be fantastically dangerous. A (alternating) current as low as 10 MICRO-Amps can be enough to cause ventricular fibrillation and cardiac arrest, if passed directly across the heart, current in the 10-20mA range causes severe muscular contractions, while 60-70 mA is usually fatal (source: Wikipedia). Seriously, let’s leave passing electric currents through the body to the professionals, eh?
Many thanks to tDCS researcher Nick Davis for helpful discussions on Twitter related to this article.