What does this attention test measure?
Response control is a go/no-go task: you build a habit of tapping, then have to stop it when a decoy appears. It reports how many decoys you tapped, how many signals you missed and your median reaction time.
Visual attention is a flanker-style task. You judge the middle arrow while the arrows around it point the same way (matching) or the opposite way (conflicting). The “distraction cost” is how much slower you were on conflicting trials — a direct look at how much irrelevant information pulled on you.
Short memory asks you to repeat a growing sequence of positions. Your result is the longest sequence you repeated correctly.
Why browser results are approximate
A browser can only register a response when the screen and input system report it. A 60 Hz display updates every ~16.7 ms, touchscreens add their own delay, and busy tabs slow everything down. Because of this, compare yourself against your own earlier attempts on the same device, not against other people or against the iPhone app.
Why your score changes between attempts
- Practice: the second attempt is usually better simply because the rules are familiar.
- State: sleep, stress, caffeine and time of day all shift short reaction-time tasks.
- Chance: with only 20–30 trials, a couple of slips move the percentage noticeably.
Is this a medical or ADHD test?
No. It’s a game-style challenge for curiosity and practice. It cannot screen for, diagnose or rule out any condition. If you’re worried about attention or memory, please speak with a qualified professional.