Go/No-Go Test — Impulse Control Test
Press for green circles, hold back for red — 45 rapid trials (5 practice + 40 scored, about 75% green) build an urge to press that your score depends on resisting.
What this test measures
Response inhibition — the ability to cancel a prepotent action. Green circle = press space or click as fast as you can; red circle = do nothing. The test runs 45 trials: the first 5 are unscored practice, then 40 scored trials in which roughly 75% are green. That Go-heavy ratio is deliberate — it builds an automatic 'press' habit that the rare red circles force you to override. Each stimulus stays on screen for only 800ms, and a fixation cross of unpredictable length (0.4-1s) precedes it, so you cannot rely on rhythm. Your raw score is a composite: commission errors (pressing on red) × 50 plus mean Go reaction time × 0.5 — lower is better. Pressing on more than 5 red circles caps your percentile at 25, because at that point speed no longer means control.
The science behind it
The go/no-go paradigm descends directly from F.C. Donders' c-reaction, described in his 1868/1869 work on the speed of mental processes — respond to one stimulus type, withhold to another. It remains one of the two standard laboratory measures of response inhibition, alongside the stop-signal task formalized in Logan & Cowan's 1984 race model (Psychological Review; see also Logan 1994 for the practical guide). In the influential Miyake et al. 2000 framework (Cognitive Psychology), inhibition is one of three core executive functions, and commission errors on go/no-go tasks are a standard impulsivity index in research on ADHD, addiction, and risk-taking. Our percentile uses a composite norm (mean 330, SD 80) estimated from this literature — an initial estimate, flagged as pending recalibration until our own sample is large enough.
How to improve your impulse control
Be honest about what training can do. Practice on inhibition tasks reliably improves performance on that task, but reviews of brain-training research find little evidence that gains transfer far beyond the trained paradigm (Simons et al. 2016, Psychological Science in the Public Interest). Within this test, the biggest lever is strategy: the composite makes one false press cost as much as adding 100ms to your average Go reaction time, so slowing down slightly on every trial to identify the color before your finger moves is usually a net win. Avoid settling into a motor rhythm — the unpredictable fixation interval punishes it. Between sessions, the basics matter: inhibitory control is measurably worse when sleep-deprived or under the influence of alcohol, and it recovers with rest. Expect improvement in points, not a personality change.
Frequently Asked Questions
What is a good Go/No-Go score?
Lower is better. Against the composite norm (mean 330, SD 80), anything under 330 beats the average; under 250 is roughly the top 16%, and around 200 is about the top 5%. As a concrete anchor: zero false presses with a 300ms mean Go reaction time scores 150 — roughly the top 1-2%.
How is the Go/No-Go score calculated?
Raw score = commission errors × 50 + mean Go reaction time × 0.5, computed over the 40 scored trials (the 5 practice trials never count). That weighting makes one press on a red circle cost exactly as much as being 100ms slower on average across the green ones. If you make more than 5 commission errors, your percentile is capped at 25 regardless of speed.
What are commission and omission errors?
A commission error is pressing when a red circle appears — the classic laboratory index of impulsivity. An omission error is failing to press within 800ms of a green circle, usually read as a lapse of attention rather than poor inhibition. Only commission errors and Go speed enter the composite score behind your percentile; omissions simply don't count as hits.
Is this the same as a stop-signal test?
They are cousins, not twins. In go/no-go, the no-go stimulus (red circle) appears instead of the go stimulus, so you decide not to start the action at all. In the stop-signal task, a stop cue arrives after the go stimulus, forcing you to cancel an action already underway — the paradigm behind Logan & Cowan's 1984 race model. Both load on response inhibition, but stop-signal isolates cancellation, while go/no-go mixes inhibition with decision speed.
Can impulse control be trained?
You can definitely improve your score here — practice effects on inhibition tasks are real and fast. What the evidence does not support is broad transfer: reviews such as Simons et al. 2016 find that training gains tend to stay close to the trained task. Treat your percentile as a snapshot of current inhibitory performance under time pressure, and retest under similar conditions (device, time of day, sleep) for a fair comparison.
More Cognitive Tests
Color words flash in sometimes-mismatched ink — respond to the INK color, not the word. 40 scored trials measure your Stroop effect: the interference cost in milliseconds.
Press the direction of the center arrow while ignoring the four flanking arrows — 5 practice trials, then 40 scored trials measure your flanker effect in milliseconds.
Click when the screen turns green — and don't fall for the distractor colors. 20 rounds measure your average visual reaction time in milliseconds.