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Go/No-Go Test

Press for every green circle. Hold back on every red square. Most shapes are circles.

Type
Attention
Takes
about 1 min
Result in
milliseconds

Go/No-Go

~1 min

  1. Green circle: press as fast as you can. Tap the box, or press Space.
  2. Red square: don't press. Let it go.
  3. 40 shapes, most of them circles. Each one is gone in 0.8 seconds.

Your result: — ms

How it's measured

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What is a Go/No-Go test?

A Go/No-Go test shows one shape at a time and asks you to respond to some shapes (Go) and not to others (No-Go). Because most shapes are Go, pressing becomes a habit, and the No-Go shapes test whether you can stop it in time. It measures two things at once: how fast you respond, and how well you hold back.

What does the Go/No-Go test measure?

It measures response inhibition: stopping an action that has become automatic. Fast responses to the Go shapes show your speed; holding back on the No-Go shapes shows your control. Pressing for a No-Go shape is called a commission error, and missing a Go shape an omission error.

How this test works

There are 40 shapes: 30 green circles and 10 red squares, in random order. The first two are always circles, and there are never more than two squares in a row. Each shape stays up for 0.8 seconds, with a blank pause of 0.7 to 1.3 seconds between shapes.

  • Green circle: press Space or tap the box, as fast as you can, before it disappears.
  • Red square: do nothing and let it go.

The circle and the square differ in shape as well as color, so you don't need to tell red from green to play.

How is your result calculated?

Each circle is timed from the animation frame that draws it to the moment your key or finger goes down, using the timestamp your browser gives the press. Your main result is the average time of the circles you hit. Alongside it you see three counts:

  • Circles hit, out of 30. A circle that disappears before you press is a miss.
  • Squares pressed, out of 10: the times you couldn't hold back. Psychologists call these commission errors, or false alarms.
  • Too soon: presses during the blank pause, before any shape. They aren't scored, but they show how often you pressed in anticipation.

Why is it hard to hold back?

Because three shapes in four are circles, your hand gets ready to press before you have even seen what came up. Stopping a response that is already on its way takes a separate act of control, and it has to happen fast. Going faster usually means more squares pressed by mistake; holding back on every square usually means slower circles. The two numbers together describe how you balanced them.

Tasks like this are old. In 1868 the Dutch physiologist Franciscus Donders compared a simple reaction, a choice between responses, and a reaction to only one of several signals, which is the Go/No-Go idea, to estimate how long a decision takes. Versions of it are still used in psychology research today.

What can change your result

  • Keyboard or touch. A thumb on Space needs no aiming; a finger on a phone screen may add touch processing time.
  • Your strategy. Deciding to be careful slows your circles and saves squares. Pick an approach and keep it if you want to compare runs.
  • Device delays. Screen refresh and input lag add a little to every press, as in every browser reaction test.

What this test does not measure

It measures how you responded to 40 shapes on your device, in one sitting. Go/No-Go tasks are used in research, but this isn't a test for ADHD, impulsivity or any other condition, and results from different devices aren't directly comparable. For another test of ignoring what doesn't matter, try the Flanker Test or the Stroop Test.

Questions

Why are most of the shapes circles?
So that pressing becomes a habit. With 30 circles to 10 squares, holding back on a square means stopping a response you were about to make, which is what the test is about.
What happens if I press too early?
A press in the blank pause, before a shape appears, isn't scored for or against you. It is counted as too soon so you can see how often you anticipated.
Which is worse, a missed circle or a pressed square?
Neither, they are different mistakes. Missed circles usually mean you were being cautious; pressed squares mean you were going fast. Both are shown so you can see the balance.
I'm color-blind. Can I play?
Yes. The Go shape is a circle and the No-Go shape is a square, so the shape alone tells you what to do.
Is the Go/No-Go task used in psychology?
Yes. It is one of the most common ways researchers study response inhibition, and versions of it appear in some clinical assessments. This online version is a game: it can't assess or diagnose anything.