I'm sorry, but considering I study neuroscience every day, this is a load of garbage. It's not the research that's flawed, it's the conclusions that are preposterous. You cannot extrapolate objective findings to completely unpredictable situations. Let me just put it simply like this to illustrate how little we know about the brain: activation and deactivation of neurons appears as identical activity under imaging. The thought that the shock in a certain area will get you into a 100% subjective state of mind is ridiculous. Until you implant electrodes into an amateur athlete and see them all perform like professionals, let's keep the science in the lab.
From what I understood from the article (and I haven't read the primary papers yet), the technique is thought to depolarize the membranes (which, if you know how neurons work, actually brings the cells closer to firing threshold), rendering them more susceptible to inputs.
I'm unclear on what you mean about activation and deactivation of neurons appearing as identical under imaging. What kind of imaging are you talking about? If fMRI, then the only way I can see that those two processes would show identical activity is if we're measuring BOLD responses caused by an excitatory population of cells and an inhibitory population of cells. But in both cases, we're measuring "positive" activity (although one will result in another population of cells being activated and the other will result in deactivation).
And what, exactly, is a load of garbage? I never saw them claim that this will put them in a 100% subjective state (whatever that means), or that this technique can generalize to all people in all situations. Which conclusion/interpretation are you criticizing here? And who made these conclusions? Michael Weisend?
Assuming the described study was well controlled, the results are fascinating, and offer unique insight into the mechanisms underlying the phenomenon of flow.