Go/No-Go Impulsivity Test — Free 60-Trial Response Inhibition Task

The Go/No-Go task is a classic way to measure response inhibition — the ability to stop an action that has already begun. Descended from the continuous performance test introduced by Rosvold and colleagues in 1956, it has you respond to most stimuli and withhold only on the rare ones, revealing how well you rein in a hand that wants to press.

A 3D sphere appears in the center of the screen for 1.5 seconds at a time. Tap as fast as you can when it is blue (Go); press nothing and wait for it to disappear when it is red (No-Go). Of 60 trials, 42 are blue (70%) and 18 are red (30%). The blue majority is deliberate: it builds a habit of responding, then creates moments where that habit has to be suppressed.

A failed inhibition is less a lapse of attention than a question of how fast the prefrontal cortex can brake a motor command — which makes this a useful window on both impulse control and sustained attention.

The headline accuracy is the number of blue spheres you tapped in time plus the number of red spheres you held back on, divided by 60 trials, as a percentage. 90% or above is described as stable inhibition and sustained attention. The results screen also lists correct Go, correct No-Go, commission errors (responding to red), omissions (missing blue) and mean reaction time for correct responses.

Commission and omission errors mean different things. Many commissions indicate difficulty stopping a response; many omissions indicate attention drifted and stimuli were missed. Very fast reaction times with many commissions may reflect prioritizing speed, while slow reaction times with many omissions may reflect flagging concentration.

Sixty trials is fairly short, so even one or two slips move the percentage noticeably. Mistakes are common on a first attempt while you get used to the rule, and devices with touch latency can record reaction times tens of milliseconds late — so look at the trend over several measurements on the same device.

Response inhibition is especially sensitive to sleep and arousal. Commission errors rise on short-sleep days, and right after a lot of coffee responses get faster but errors can climb too. Late nights and post-meal drowsiness increase omissions. With age, a more cautious pattern is common: reaction times lengthen slightly while commissions decrease.

Comparing a well-rested day with a sleep-deprived one, or before and after coffee, shows you which conditions shake your inhibition. Soundary stores results and shows the change from your previous test, so repeat every one to two weeks on the same device and watch the trend. This is a self-check and does not provide a diagnosis.

If you keep responding to red spheres even when well rested, and in daily life your words or actions often get ahead of you in ways that cause trouble, it may be worth considering an attention and impulsivity assessment with a psychiatrist.