Exciting! Reports from self-experimenting starting to come in! In this case the author used the Cambridge Brain Challenge suite of tests to guage the effect of tDCS.

Observations The most immediatley obvious and striking effect of tDCS is the modest but significant increase in Paired Associates score during excitatory tDCS. This score, which measures the ability to remember the locations of objects on a screen, likely correlates with overall working memory, which has been previously shown to be improved by exciting the left DLPFC.

Another striking effect is that of excitatory tDCS on the Odd One Out test, a general test of fluid intelligence. Although it only reached a significance level of 0.41, the 1.6667 point average improvement is this task represents a very large gain in performance…

via Effects of inhibiting and exciting the left DLPFC–an experiment : tDCS.