mindlsn / mind lesson

Track that you're getting sharper.

Seven drills across five cognitive domains. One rating per drill, tracked honestly. No claims about IQ, no claims about cognitive decline - just a measurement of how sharp you are this month versus last.

Begin the first drill ›

The drills

seven daily drills

Working memory Digit Span. Forward digit recall, one digit per second. Adaptive ceiling. Play ›

Arithmetic Fast Math. Speed-accuracy with operator mix. Enter submits, 60s window. Play ›

Processing speed Reaction Time. Five trials, 2–5s random delay. Tap or spacebar; trimmed mean RT (middle 3 of 5). Play ›

Visuospatial Mental Rotation. Which of the four matches the source under rotation? Correct − incorrect over 60s. Play ›

Working memory N-back. N-back match rate over a three-minute stream of letters. Play ›

Inhibition Stroop. Name the ink, not the word. Correct count over 30s. Play ›

Fluid reasoning Sudoku. Standard 9×9 grid, tiered solve time. Errors tracked silently. Play ›

How Mind index works.

five domains / weighted sum / unbounded

Each cognitive domain has its own per-game skill rating. Mind Index is the weighted sum of those ratings, sorted highest first, with weights 1.0, 0.8, 0.7, 0.5, 0.3 - so the more domains you cover, the higher it climbs, with diminishing returns past three. Population growth never moves your number, and long inactivity fades it gradually rather than resetting it.

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