Learn a new language faster than ever! Leave doubt in the dust! Be a better sniper! Could you do all that and more with just a zap to the noggin? Maybe. Sally Adee, an editor at New Scientist, was at a conference for DARPA - The Defense Advanced Research Projects Agency - when she heard about a way to speed up learning with something called trans-cranial direct current stimulation (tDCS). A couple years later, Sally found herself weilding an M4 assualt rifle, picking off enemy combatants with a battery wired to her temple. Of course, it was a simulation, but Sally's sniper skills made producer Soren Wheeler wonder what we should think of the world of brain stimulation.  In the last couple years, tDCS has been all over the news. Researchers claim that juicing the brain with just 2 milliamps (think 9-volt battery) can help with everything from learning languages, to quitting smoking, to overcoming depression. We bring Michael Weisend, neuroscientist at Wright State Research Institute, into the studio to tell us how it works (Bonus: you get to hear Jad get his brain zapped). Peter Reiner and Nick Fitz of the University of British Columbia help us think through the consequences of a world where anyone with 20 dollars and access to Radioshack can make their own brain zapper. And finally, Sally tells us about the unexpected after-effects of a day of super-charged sniper training and makes us wonder about world where you can order up a state of mind.   Special thanks for the music of Brian Carpenter's Ghost Train Orchestra