It's likely lots of intellectually challenging activities produce structural/che...

It's likely lots of intellectually challenging activities produce structural/chemical changes in the brain:

piano tuning

http://www.bbc.co.uk/news/health-19398413

playing musical instrument

http://www.sott.net/articles/show/216086-Mental-muscle-six-w...

I would expect similar effects from learning diff eq's or haskell and maybe from challenging sports like rock climbing, paragliding, or maybe Ashtanga yoga.