An interesting and observable self metric I've been able to use to assess my mental acuity has been to look at my statistics on clearing 40 lines in Tetris. (te

An interesting and observable self metric I've been able to use to assess my mental acuity has been to look at my statistics on clearing 40 lines in Tetris. (tetr.io if anyone else is interested) On fully rested, deep sleep days, I can drop the tetronimoes at 1.5 to 1.6 pieces per second (pps), while, sleep deprived states (4-5 hours), no matter how hard I try (and it "feels" like I'm performing very fast) drops to 1.2-1.3 pps. There's also a bit of a qualitative measure on how difficult it was to sustain focus for the 1 minute to 1.5 minutes that gives me an idea of my ability to focus and perform.