I'd suggest to record all of the foods you eat each day. Just a quick list. Also total calories would be interesting, and exercise.<p>I tracked diet, and my estimates of mental functions for a while and surprisingly found that strawberries increased my mood considerably. Of course I could just be bad at statistics :-(
It's an interesting test for sure. I do similar with brain training on the 3DS, and though I've always been mindful of the various factors affecting my performance, I've never gone the effort of mapping them vs. my results.<p>As noted, as long as you don't start drawing any conclusions before you've played consistently to eliminate practice effects (getting better at the games) as best you can, it's fairly interesting and valuable stuff.
Hey all, author here. What I'd really like is feedback from statisticians / cognitive scientists about better / less biased ways to perform these tests and the analysis.