Go/No-Go Task: The Hard Part Is Not Tapping
The Go/No-Go task is the standard laboratory measure of inhibitory control. Shapes appear about every second and a half and you tap for circles — which quickly becomes a habit — until a square arrives and you have to stop a movement that is already underway. Most people find the tapping trivial and the not-tapping surprisingly hard. That gap is the whole measurement, and this version scores it with d′ rather than raw accuracy so the easy trials can't flatter you.
Not a diagnostic tool. Go/No-Go tasks appear widely in research on ADHD, autism, and substance use, so results from them are easy to over-read. This version is a practice and self-tracking exercise: it is not validated, not normed, and it cannot screen for or indicate any condition.
A quiet round of Go/No-Go Task — Standard, 75 sec. When you start, everything else fades — just you and the task.
No sign-up needed. Press Esc to exit anytime.
Tip
Don't sit with the tap already loaded. Three shapes in four are circles, so it is tempting to hold the movement ready and release it on sight. That readiness is exactly what a square then asks you to cancel, and it is where false starts come from.
Everything here is free
Every test, every difficulty, no limit and no account. If it is useful to you, you can chip in — entirely optional, and nothing changes either way.
Go/No-Go Task: what it is and where it comes from
What is a Go/No-Go task? The Go/No-Go task measures response inhibition: you respond quickly to frequent go stimuli and hold back on rare no-go stimuli. It has no single origin paper — it descends from Donders's 1868 subtractive method and has been reinvented across several literatures. Focani's free browser version runs 48 trials per session and needs no sign-up.
| Specification | Go/No-Go Task |
|---|---|
| Primary cognitive domain | Response inhibition — in the “Holding a rule under pressure” group |
| Original citation | No single published source. No single origin paper. The procedure descends from Donders's (1868) subtractive method and has been independently reinvented across the developmental, addiction and clinical literatures, with the ratio of go to no-go trials and the stimuli differing in each. |
| Core dependent metrics | Hits · False alarms (commission errors) · Misses (omission errors) · Correct rejections · Mean reaction time (ms) · Reaction-time variability (SD, ms) |
| Standard stimulus / trial parameters | Varies widely by literature. Go trials outnumber no-go trials so that responding becomes the prepotent habit that has to be withheld. |
| This version | Standard — 48 trials · Extended — 72 trials |
| Browser adaptation notes | The parameters here are ours, because there is no reference version to match. That makes the demonstration valid and the number meaningless outside this site. |
Full sources for every test, and what each version changes, are on the instructors page.
How to play
- A shape appears for about half a second, roughly every second and a half.
- Circle: tap the panel, or press the space bar. Go as fast as you comfortably can.
- Square: do nothing at all. Three out of four shapes are circles, so the urge to tap will already be running.
- The task runs on its own clock — you can't speed it up or pause it. Standard takes about eighty seconds, Extended about two minutes.
Go/No-Go Task tips
Ways to play it better — each one comes from how this version actually scores, not from general advice about concentration.
Don't sit with the tap already loaded
Three shapes in four are circles, so it is tempting to hold the movement ready and release it on sight. That readiness is exactly what a square then asks you to cancel, and it is where false starts come from.
Let post-error slowing pass
After a false start, responses get noticeably slower for the next several trials — a well-documented reaction, not a correction. It costs Go speed without making the next square any easier, and the run is short enough that there is little room to earn it back.
The clock is not yours to beat
Shapes arrive on a fixed schedule, so the run takes the same time however hard you push and there is nothing to win between trials. What speed does count for is your reaction time on the circles, and it is capped at about fifteen percent of the score — applied on top of your inhibition, never instead of it.
One caveat worth knowing: a change of strategy moves your score for reasons that have nothing to do with attention. Your dashboard reads each session against your own recent ones, so if you adopt something from this list, give it a few sessions before reading anything into the trend.
Frequently asked questions
What does the Go/No-Go task measure?+
Response inhibition — your ability to cancel an action you have already started preparing. Because most trials call for a response, tapping becomes the default, and every No-Go trial asks you to override that default under time pressure.
Why isn't my score just my accuracy?+
Because accuracy here has a ceiling. Three quarters of the trials are easy Go trials, so almost everyone lands above 90% overall and the number tells you nothing. The signal lives in the few trials where you tapped on a square. This test scores with d′ from signal detection theory, which compares your hit rate against your false-alarm rate — so two sessions with identical overall accuracy can score very differently, which is exactly the point.
Should I go as fast as possible?+
Fast, but not reckless. Speed can only move your score by about 15% here, deliberately: in this task, mashing the panel as fast as possible produces excellent Go performance and terrible inhibition, and rewarding that would reward the very failure the task exists to expose. Speed only counts once your d′ is high.
Does this show whether I have ADHD?+
No. Go/No-Go tasks are used in research on ADHD, autism, and substance use, which is exactly why it's worth being clear: this version has no clinical validation, no age-matched norms, and no trained administration. A low score on one run means you had a distracted minute, nothing more. If you have real concerns about your attention or impulsivity, talk to a professional.
What counts as a false start?+
Tapping on a square — a commission error, in the literature. Missing a circle is an omission error, and it's counted separately because it means something different: false starts point to weak braking, misses point to attention drifting off the task altogether.
Where this fits
- Mind Wandering — The same signal-detection shape as the task above, but tuned for braking rather than for drifting — stops come often enough to stay effortful. Its missed circles are still the drift: the shape was there, on its own clock, and you were not.
Related attention paradigms
Holding a rule under pressure — closest to this one
- Stroop Test — practices and measures selective attention and mental control.
- Simon Effect Test — practices and measures response conflict and inhibitory control.
- Flanker Test — practices and measures selective attention and interference control.