Are the measured effects of tDCS really large enough to outweigh any effects from confirmation bias and statistical anomalies? Were the tests performed double-blind using placebo units?
I was skeptical that simple, unguided tDCS could have significant effects so I searched some more and found a very nice overview paper: http://www.aipass.org/files/TDCS_State%20of%20the%20art.pdf "Transcranial direct current stimulation: State of the art 2008"
I was looking for something, anything, that would tell me if there's significant research in the area and if simple procedures that could be carried out using this kit would work.
(Also you might note that the Nature article was linked 9 hours after my post :) In some ways it does give a better overview of the technique, I'd link it if I had found it.)
This keeps getting thrown around but I'm having a hard time identifying a good source (other than a bunch of blogs repeating the same 'fact'). The best I can do is this set of slides which claim 'a 2.1x improvement' [1], but no confirmation that it's actually in use.
The brain is very poorly understood, and throwing random electrical fields across it "because I saw it on extremetech" is a terrible idea.
Zap your brain into the zone: Fast track to pure focus http://www.newscientist.com/article/mg21328501.600-zap-your-...
Which references Experimental Brain Research, vol 213, p 9: http://www.mendeley.com/research/transcranial-direct-current...
Nevertheless, they probably wouldn't have funded it without some indication that it could be useful.
Reasons range from "it works" through "it's a safe useful placebo" through "it might work" to "it doesn't work, but it'll confuse (and scare) the communists and divert them from our real research."