01.
Millisecond-Accurate Paint Sync Calibration
Standard browser reaction timers initiate time-captions during a state trigger, letting the browser queue and paint the visual state change asynchronously. This introduces a variable latency jitter of 8ms to 32ms depending on GPU scheduling and screen refresh rates.
BrainBenchmarks resolves this by measuring reaction triggers using a double-nested requestAnimationFrame (rAF) loop. The start timestamp is locked only when the browser confirms the paint buffer has updated, matching real-world photon emission delays.
// Visual trigger paint synchronization
requestAnimationFrame(() => {
requestAnimationFrame(() => {
startTime.current = performance.now();
});
});
02.
Hick's Law (Choice & Decision Latency)
Hick's Law states that the time it takes to make a decision increases logarithmically with the number of alternatives:
RT = a + b · log₂ (n)
In our Choice Reaction Test, n = 4. This logarithmic increase represents prefrontal cortex stimulus-classification delays. We calibrate this by subtracting the participant's simple reaction time base to measure pure decision-overhead.
03.
Fitts's Law (Spatial Aim Precision)
Fitts's Law predicts that the time required to rapidly move to a target is a function of the ratio between the distance to the target and the width of the target:
MT = a + b · log₂ (2D / W)
Our Aim Precision Trainer logs pinpoint coordinate offsets (sub-pixel distances from target center) and target acquire latency. This indexes the efficiency of the motor-cortex feedback loops governing spatial control.
04.
Auditory Low-Latency Web Audio API
Playing compressed audio formats like .mp3 or .wav via HTML5 <audio> elements triggers decoder setup overhead and buffer delay.
Our Sound Reflex Test synthesizes a pure 750Hz sine tone directly on the audio hardware thread using the Web Audio API OscillatorNode. This minimizes audio emission delay to sub-millisecond ranges.
05.
Miller's Law (Working Memory)
Miller's Law states that the average human short-term working memory span can hold approximately 7 items or "chunks" (7 ± 2).
The Sequence Memory Test evaluates this boundary. By chunking coordinate lists into visual shapes, patterns, or vectors, participants can bypass Miller's Law limits and reach higher levels.