Simon task online: can you ignore where it appears?
See how quickly you can answer to a shape while its position tugs you the other way. It's the split-second control you use when a sign on your left points right, behind the wheel or on a busy screen.
Scored part: 3 minutes at most. Tutorial and practice included, nothing to prepare.
Answer to the shape. Ignore where it appears.
- 1
Learn and practice
A short tutorial, then 6 practice rounds that don't count.
- 2
60 scored rounds
Answer to the shape; the next round simply appears.
- 3
Your results
Your own numbers, read against reference ranges.
What is the Simon task?
The Simon task is a classic cognitive interference test. A circle or a square appears on the left, on the right or in the center of the screen, and you press the button for the shape while ignoring where it shows up. It measures how well you hold back the automatic pull toward that side. CogniFit's Circle or Square is a digital version of this paradigm.
Answer the shape, not the side
The circle button sits on one side and the square button on the other. Sometimes the shape lands on its own button's side, sometimes on the opposite one. Here are the three kinds of round you'll meet.
Congruent. The circle appears on the left, the same side as the circle button. Position and answer agree, so this round feels easy.
Incongruent. The circle appears on the right, on the square button's side. Its position pulls your hand toward the wrong button; holding that pull back is what the task measures.
Neutral. The square appears in the center. Its position favors neither button, which gives a baseline to compare the other two rounds against.
The three kinds are mixed through the task rather than run in blocks, about 34% congruent, 34% incongruent and 32% neutral, so tiredness isn't mistaken for the difference between them.1
Every round, in three beats
- 1
A fixation point
A small mark in the center tells you where to rest your eyes.
- 2
A shape appears
Circle or square, left, right or center, with up to 3 seconds to answer.
- 3
You press, it moves on
No right-or-wrong message in the scored part: the next round just appears.
Now you know the rule. Will your hand agree?
What the Simon task measures
One ability sits at the center of this attention test: stopping a response that the shape's position fires off on its own. Three more come along with it.
- Interference suppression
- Holding back the automatic response triggered by an irrelevant location.
- In everyday lifeAt a junction, a sign on your left points to an exit on your right.
- Adaptive control
- Adjusting how carefully you respond as easy and hard rounds come and go.
- In everyday lifeSlowing down a touch after a near-miss while typing, then finding your pace again.
- Processing speed
- How quickly you take in what you see and turn it into a decision.
- In everyday lifeNoticing the light has turned green and moving off without a pause.
- Visuomotor integration
- Turning what your eyes see into the right movement of your hand.
- In everyday lifeTapping the right option on a self-checkout screen.
The task's main measure is the first one; the other three are part of how every answer is timed and scored.
Curious how your attention handles a misleading cue?
How to read your result
When you finish, the task shows your own results and reads them against reference ranges. Times are in milliseconds, thousandths of a second. Four figures tell most of the story.
Reaction time
How long you took to answer. The median is your typical time: half your answers were faster, half slower, so one slow round doesn't move it.
Lower means fasterAccuracy
Out of every hundred answers, how many were right. Errors and rounds you didn't answer are counted separately.
Higher means more accurateSteadiness
How much your speed varied from one answer to the next. A small figure means an even rhythm; a large one, bursts of fast and slow. A version scaled to your own speed lets a fast and a slow person be compared on steadiness alone.
Lower means steadierThe key measure: interference cost
It's a simple comparison: how much slower you were on incongruent rounds than on congruent ones.
Incongruent time − congruent time = your cost
A smaller gap means the shape's position slowed you less. Your results also compare incongruent rounds with neutral ones, the cost of the conflict on its own, and show facilitation: how much faster you were when the side agreed with the answer.
Every figure above comes from your own 60 rounds.
The science behind the Simon effect
When the side a shape appears on matches the side of its button, answering comes easily. When it doesn't, you have to override the pull, and that delay is the Simon effect, one of the classic tools of cognitive testing for studying control over automatic responses.
Each round sets two pieces of information against each other: the shape, which you answer, and its position, which you are asked to ignore. The position still pulls at your hand, and that pull is what the task makes visible. The classic description of this effect of an irrelevant cue comes from Simon and Rudell (1967).2
Because congruent, incongruent and neutral rounds are compared within the same session, the task can separate the cost of the conflict from your overall speed. That is why research uses the Simon task to study how people handle irrelevant location information, as reviewed by Lu and Proctor (1995)3 and discussed by Hommel (2011) as both a research tool and a way of thinking about response conflict.4
Reference ranges describe groups of people, not one person: they show where a score sits, not what it means for you. Studies such as Bialystok, Craik, Klein and Viswanathan (2004) use the task to compare cognitive control between groups, for instance across ages and between people who speak one or two languages; findings like these describe groups, not any single participant.5
More on how this version is built
Circle or Square follows the published procedure of the Simon task: what is shown, for how long, what counts as an answer and what is measured all come from it rather than being invented for this version.
Congruent, incongruent and neutral rounds are interleaved, and the order is drawn fresh each time, so you can take the task again without meeting the same sequence. Steadiness is computed on correct answers only, because the timing of an error comes from a different process.
Each session also runs quality checks, such as answers that came back too fast to be real, to decide whether it can be read at all. Those checks describe the session, not the person.
A classic idea, 60 rounds, one quiet minute of focus at a time.
Questions about the Simon effect test
How long does the Simon task take?
The scored part is 60 rounds of up to 3 seconds each, so 3 minutes at most. Before it come a short tutorial and 6 practice rounds, which aren't counted in that time.
Do I need an account to take it?
No. You can take the Simon task online right here, without an account. At the end the results screen shows your figures and offers to sign up if you'd like to keep track of your results over time.
Can I take it on my phone?
Yes. It works on a computer, a tablet or a phone, and you answer with two buttons on the screen.
Will I know when I get one wrong?
During the tutorial and practice you learn the rule; you can repeat the tutorial as many times as you like before starting. In the scored part you aren't told whether an answer was right: the next round simply appears.
Can I take it again?
Yes. The shapes and their order are drawn fresh every time, so you won't repeat the same sequence.
Is my result a diagnosis?
No. Your result is a measure of how you performed in one session, read against reference ranges. It isn't a clinical assessment and says nothing about your health.
You know what it measures. Now see yours.
Circle or square, left or right: 60 rounds to find out how much a shape's position pulls at your hand.
More attention tasks in the series
Sources
- CogniFit. Circle or Square (Simon Task): task description, conditions and measures.
- Simon, J. R., Rudell, A. P. (1967). Auditory S-R compatibility: The effect of an irrelevant cue on information processing. Journal of Applied Psychology, 51(3), 300-304. https://doi.org/10.1037/h0020586
- Lu, C.-H., Proctor, R. W. (1995). The influence of irrelevant location information on performance: A review of the Simon and spatial Stroop effects. Psychonomic Bulletin & Review, 2(2), 174-207. https://doi.org/10.3758/BF03210959
- Hommel, B. (2011). The Simon effect as tool and heuristic. Acta Psychologica, 136(2), 189-202. https://doi.org/10.1016/j.actpsy.2010.04.011
- Bialystok, E., Craik, F. I. M., Klein, R., Viswanathan, M. (2004). Bilingualism, aging, and cognitive control: Evidence from the Simon task. Psychology and Aging, 19(2), 290-303. https://doi.org/10.1037/0882-7974.19.2.290
This content and the task are for information only. They are not medical advice, not a diagnosis, and do not replace care from a qualified health professional.
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