Sally Adee tested out transcranial direct current stimulation (tDCS), where electrodes attached to your head send the current of a 9-volt battery through your brain:
The 20 minutes I spent hitting targets [with a rifle] while electricity coursed through my brain were far from transcendent. I only remember feeling like I had just had an excellent cup of coffee, but without the caffeine jitters. I felt clear-headed and like myself, just sharper. Calmer. Without fear and without doubt. From there on, I just spent the time waiting for a problem to appear so that I could solve it.
It was only when they turned off the current that I grasped what had just happened. Relieved of the minefield of self-doubt that constitutes my basic personality, I was a hell of a shot. And I can’t tell you how stunning it was to suddenly understand just how much of a drag that inner cacophony is on my ability to navigate life and basic tasks.
She elaborated on the experience for New Scientist. Either piece makes for a fascinating read.