PULSE — Adaptive Reaction Timing Instrument
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A precision rhythm game with real-time statistical calibration. Tap as the ring closes — the adaptive window scales to your personal reaction-time distribution, maintaining challenge at the edge of your ability.
How It Works
The game maintains a running statistical model of your absolute timing errors. On each hit, it:
- Transforms |error| via variance-stabilizing log mapping:
y = 60 · ln(1 + |error| / 60) - Fits a log-normal MLE over regime-tagged samples (slow/fast, with 60 ms hysteresis to prevent flicker)
- Sets the window to the empirical 85th percentile of the last 20 in-regime magnitudes, capped to [4.5%, 22%] of the beat cycle
- Adjusts BPM based on window tightness — narrow window → faster, wide window → slower
Late responses (t ≥ 1.0 cycle) and extreme early taps (> 6% of cycle before window) are treated as censored observations and excluded from spread estimation.
| Feature | Description |
|---|---|
| Adaptive window | Empirical 85th percentile, n ≥ 10 gated |
| Regime system | Slow/fast with hysteresis, cache invalidation on switch |
| Live visualization | Gaussian PDF + timing-error histogram |
| Session feedback | Bias, σ_log, window size, regime, difficulty tier |
Controls
| Input | Action |
|---|---|
Space or tap |
Register timing |
Esc |
End session early |
Technical Notes
- Single-file deployment. All logic, styles, and assets inline. No build step, no external dependencies.
- Canvas rendering. Game loop, particle system, and background grid via 2D context with DPR scaling.
- Responsive layout. CSS Grid with breakpoint at 720 px.
- Persistence. Personal best stored in
localStorage(pulse3_bestkey).
## Future Work
| Priority | Item | Notes |
|---|---|---|
| Bug | Fix best score persistence |
Math.max assignment order issue — one-line fix |
| Feature | Web Audio API integration | Tone.js or native oscillator for beat cues |
| Feature | Cross-session statistics | Aggregate reaction times across sessions |
| Feature | Export session data | JSON/CSV of raw timing errors for external analysis |
| Polish | Reduced motion preference | Respect prefers-reduced-motion media query |
Browser Requirements
ES2015+ (Math.log1p, ResizeObserver, PointerEvent). Modern
browsers only — Chrome, Firefox, Safari, Edge.
Running Locally
git clone https://github.com/YOUR_USERNAME/pulse-game.git
cd pulse-game
# Option 1: open directly
open index.html # macOS
xdg-open index.html # Linux
# Option 2: local server (recommended for DPR/resize testing)
python3 -m http.server 8000
# Visit http://localhost:8000
