Psychomotor
Vigilance Task
The PVT is the standard laboratory measure of behavioural alertness. It is deliberately the simplest task in this collection: nothing to learn, nothing to remember, no strategy that helps. That is what makes it work — with aptitude and practice taken out of the picture, what moves your numbers between sessions is state, not skill. What it detects is not slowness but wake-state instability: brief attentional failures intruding into otherwise normal responding.
The task
Do not press before the counter appears. Early presses are recorded as false starts and restart the wait with a fresh random interval, so pressing to a rhythm gets you nothing but a worse score. On a phone, tap anywhere instead of SPACE.
What comes out
Two numbers carry the session, and neither is your average reaction time.
Mean RT is reported too, and pointedly not scored: an average over a distribution with a long lapse tail moves mostly with that tail, so it is noisiest exactly where the signal lives — and it cannot tell uniformly mediocre responding apart from fast responding punctuated by failures. Those are different states.
These are fixed, not preferences. The parameterisation is the instrument — change the interval range or the threshold and the numbers stop being comparable with anyone else's, or with your own.
This version trades sensitivity for brevity. If you can spare the ten minutes, the standard PVT separates alert from impaired more sharply, and a vigilance decrement has room to show itself.
Go to PVT-10 — 10 min, lapse ≥ 500 ms →They are scored as separate instruments and keep separate histories. Runs on one are not comparable with runs on the other, so pick a version you can stick with rather than alternating.
This is a research-style measurement instrument and an educational demonstration — not a medical or diagnostic device. A browser adds display and input latency that a laboratory PVT device does not, so absolute values here are not comparable with published norms; what is usable is the change in your own numbers across sessions on the same hardware. Nothing here can confirm or rule out a condition, diagnose sleep disorders, or tell you whether you are fit to drive.
PVT-B (3-minute)
What this test measures
The PVT-B (Basner, Mollicone & Dinges, 2011) is the validated three-minute form of the Psychomotor Vigilance Task: stop a millisecond counter the instant it starts. It measures the same construct as the ten-minute test — behavioural alertness, the stability of attention under sleep pressure and fatigue — in less than a third of the time.
It is a re-tuned instrument, not simply a shortened one. The waits between stimuli are compressed to 1–4 seconds, which preserves most of the stimulus count and raises workload, and the lapse threshold drops to 355 ms to match the faster responding the denser pacing produces. The trade is modest sensitivity for much better adherence — its scores live on their own scale and are tracked separately from the ten-minute test.
How to use it
Three minutes makes daily testing realistic, which is where a vigilance measure earns its keep: the value is in the trend across sleep, time of day, and caffeine, not any single run. Signed-in sessions feed the brief-alertness trend on the Progress page.
Sapiens Bench tasks are educational instruments for self-tracking, not medical or diagnostic devices.