Every time I read about either tDCS or psychedelics, I'm reminded of altering random hex values in games on my Apple II+ as a kid. One tweak got me a score of 100,000,000 in Falcons, and the screen dump made for nice bragging rights on the school bus the next morning. The next one crashed the game and wrote a bad sector to the floppy.

Maybe the first such experimentation actually teaches you something? By destroying a part you get to understand the true shape of the self. But by repeated use I imagine you get diminishing effects on the knowledge, and exponential damage, as you are left unable to self heal or develop adaptations to the missing corrupted sectors