Eriksen Flanker
Follow the middle fish, ignore the crowd
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What is the Eriksen Flanker?
The Eriksen flanker task is one of the best known tests in attention research. Barbara A. Eriksen and Charles W. Eriksen introduced it in 1974. People respond to a central target, such as a letter or an arrow, while ignoring the items on either side of it, called flankers. When the flankers point to the opposite response, people tend to be slower and make more errors.
Researchers use the flanker task to measure selective attention and inhibitory control, often by comparing reaction times when flankers match the target with times when they conflict. The Neuroptimize version, Eriksen Flanker, uses a row of fish. You decide which way the middle fish is swimming while the fish around it swim the same way, the opposite way, or are replaced by bubbles.
How to play the Eriksen Flanker
- A plus sign appears in the centre of the tank. Keep your eyes on it, because a row of fish will appear in its place.
- Decide which way the middle fish is swimming and tap Left or Right. On a keyboard you can use the left and right arrow keys, or A and D.
- The fish on either side may swim the same way as the middle fish, the opposite way, or be shown as bubbles. Only the middle fish counts.
- A bar along the bottom shows your time limit for each row. Answering the wrong way shows "Wrong way", and running out of time shows "Too slow!". Both count as mistakes.
- A session lasts 45 seconds. Your results show your average reaction time and, once there are enough trials, your distraction cost: how much slower you were when the other fish swam the opposite way.
- As your level rises the time limit shortens, conflicting rows become more common, bubbles disappear, and the row grows from 5 to 7 fish. At the highest levels the row also appears in a slightly different spot each time.
Strategies and tips
Rest your eyes on the plus
The middle fish always appears where the plus sign was. Looking at that exact spot before each row means the target lands right in front of you. At higher levels the row shifts a little, so be ready to adjust quickly.
Read the head, not the tail
Each fish has an eye near its head and a triangular tail. Pick one feature, such as the eye, and check which side of the middle fish it is on. A single, consistent cue is faster than taking in the whole fish.
Expect the crowd to disagree
At higher levels most rows have flankers swimming the opposite way. Going in with the expectation that the crowd is wrong makes it easier to ignore. Conflicting rows also give a small score bonus when you get them right.
Rest your fingers on both buttons
The time limit gets short at high levels, so a thumb on each button or fingers on both arrow keys saves time. Moving your hand to reach a button can be the difference between a correct answer and "Too slow!".
Do not guess on the timer
A wrong answer and a timeout both count as mistakes, and both reset your combo. If you are unsure, a quick second look is better than a random tap. Accuracy decides whether your level goes up after the session.
The science behind the Eriksen Flanker
The Eriksen flanker task was developed by Barbara A. Eriksen and Charles W. Eriksen in 1974. Participants respond to a central target while ignoring the stimuli that flank it. Responses are slower and less accurate when the flankers indicate a different response, an effect used to measure selective attention and inhibitory control.
Frequently asked questions
What does the flanker task measure?
Researchers use the flanker task to measure selective attention, the ability to focus on relevant information, and inhibitory control, the ability to suppress an unwanted response. The key measure is usually the difference in speed or accuracy between matching and conflicting trials.
What is the flanker effect?
The flanker effect is the slowdown and extra errors people show when the surrounding items point to a different response from the target. Neuroptimize reports this as your distraction cost: your average time on conflicting rows minus your average time on matching rows.
What are congruent and incongruent trials?
On congruent trials the flankers point the same way as the target. On incongruent trials they point the opposite way. Some versions, including early levels of Eriksen Flanker, also use neutral trials, where the flankers are shapes that point nowhere.
Can I play Eriksen Flanker with a keyboard?
Yes. On a computer you can answer with the left and right arrow keys, or with A and D. On a phone or tablet, tap the Left and Right buttons below the tank.