Interesting to note that Michael Weisend is now associated with San Francisco based company Rio Grande Neurosciences.

The current was set to 2 milliamps, about 1,000 times less than the electrical current that flows through a typical iPad charger. But only about 1/50th of that current makes it through the skull to the brain, Weisend said. The stimulation, which lasted for 10 minutes, was aimed at my right inferior frontal cortex and the right anterior temporal lobe, which are brain areas thought to be important for learning. If this were a real experiment, Weisend would have scanned my brain first to determine the optimal placement for the electrode, but in my case, he made an approximation.

I turned the electricity on myself, and the first thing I noticed was the mild stinging where the electrode attached to my head. Weisend assured me this was normal, but said if the sensation continued, he would turn it off and try to get a better connection. Next I noticed a slight taste of metal in my mouth, a common side effect of tDCS, according to Weisend.

Source: LiveScience.com