Go/No-Go Test — Impulse Control Test
Press for green circles, hold back for red rings — 45 rapid trials (5 practice + 40 scored: exactly 30 green, 10 red) build an urge to press that your score depends on resisting.
What this test measures
Response inhibition — the ability to cancel a prepotent action. Filled green circle = press space or click as fast as you can; hollow red ring = do nothing (the No-Go stimulus differs by shape as well as color, so it does not depend on perfect color vision). The test runs 45 trials: the first 5 are unscored practice (4 green, 1 red), then 40 scored trials with exactly 30 green and 10 red. That Go-heavy 75% ratio is deliberate — it builds an automatic 'press' habit that the rare red rings 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 rings caps your percentile at 25, and responding to fewer than half of the green circles floors the run at the 5th percentile — in either case the score 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 grades the composite against a right-skewed log-normal norm (median 330, log-σ 0.35) — reaction-time-based scores are not symmetric, and a bell-curve fit would unfairly crush slower-but-normal performers into the bottom percentiles. The numbers are 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 shape and 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 right-skewed composite norm (median 330), anything under 330 beats the average; under 250 is roughly the top 21%, and around 200 is about the top 8%. 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 ring cost exactly as much as being 100ms slower on average across the green circles. Presses landing within 100ms of the stimulus appearing are anticipations — they cannot be stimulus-driven and are excluded from your reaction-time average. Two validity rules apply: more than 5 commission errors caps your percentile at 25 regardless of speed, and responding to fewer than half of the green circles floors the run at the 5th percentile. A run with no Go responses at all produces no score — you'll be asked to try again.
What are commission and omission errors?
A commission error is pressing when a red ring 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. Omissions don't enter the composite score directly, but they are not free: miss more than half of the green circles and your run is floored at the 5th percentile, because a run that ignores most Go stimuli no longer measures inhibition.
Is this the same as a stop-signal test?
They are cousins, not twins. In go/no-go, the no-go stimulus (red ring) 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. 12 scored rounds measure your average simple visual reaction time in milliseconds — then a 6-round distractor block tests your impulse control separately.