Attention
Eriksen Flanker Task
Measure selective attention and conflict cost with a browser-native version of the classic Eriksen Flanker paradigm.
4-5 minTimed: desktop or laptop with a mouse or trackpad
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Try it here first, with no account.
- Papers, 2021 to 2025
- 1,472
- Evidence grade
- A
- Registered clinical studies
- 334
Example data
One session, scored by the code that scores your study's sessions.
Flanker Effect
47.7ms
Incongruent RT minus congruent RT.
Quality check: valid48 scored trials
- Congruent RT
- 469.2 ms
- Incongruent RT
- 516.9 ms
- Congruent Accuracy
- 95.8%
- Incongruent Accuracy
- 95.8%
- Overall Accuracy
- 95.8%
- Congruent
- Incongruent
- Mean
- Wrong answer
Trial file
The first 6 of 56 rows, with the column names of your study's export.
| participant_id | test_slug | test_version | scoring_version | trial_index | trial_type | response | rt | correct | time_elapsed | condition | correct_response | direction | plugin_version | run_id | task |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| simulated | flanker | 1.0.0 | 1.0.0 | 0 | html-keyboard-response | ArrowRight | 456 | true | 3356 | incongruent | ArrowRight | right | 2.1.0 | example-run | flanker_practice |
| simulated | flanker | 1.0.0 | 1.0.0 | 1 | html-keyboard-response | ArrowLeft | 519 | true | 4375 | congruent | ArrowLeft | left | 2.1.0 | example-run | flanker_practice |
| simulated | flanker | 1.0.0 | 1.0.0 | 2 | html-keyboard-response | ArrowLeft | 428 | true | 5303 | congruent | ArrowLeft | left | 2.1.0 | example-run | flanker_practice |
| simulated | flanker | 1.0.0 | 1.0.0 | 3 | html-keyboard-response | ArrowRight | 503 | true | 6306 | incongruent | ArrowRight | right | 2.1.0 | example-run | flanker_practice |
| simulated | flanker | 1.0.0 | 1.0.0 | 4 | html-keyboard-response | ArrowRight | 400 | true | 7206 | congruent | ArrowRight | right | 2.1.0 | example-run | flanker_practice |
| simulated | flanker | 1.0.0 | 1.0.0 | 5 | html-keyboard-response | ArrowLeft | 562 | true | 8268 | incongruent | ArrowLeft | left | 2.1.0 | example-run | flanker_practice |
What it measures
Measures selective attention and cognitive control by requiring participants to identify the direction of a central arrow while ignoring flanking arrows.
Constructs
- Selective attention
- Cognitive control
- Conflict monitoring
- Response interference resolution
Research uses
- ADHD attentional assessment
- NIH Toolbox cognitive screening
- Aging and cognitive decline research
- Executive function evaluation
- Pharmacological intervention studies
How the paradigm works
The Eriksen Flanker Task measures selective attention and cognitive control. Participants view a row of five arrows and must identify the direction of the central arrow while ignoring the flanking arrows. On congruent trials, all arrows point the same direction (< < < < <). On incongruent trials, flankers point opposite to the target (< < > < <).
More about the paradigm
This task is part of the NIH Toolbox Cognition Battery and is one of the most widely used measures of attentional control in cognitive neuroscience. The flanker effect is sensitive to aging, ADHD, and executive function deficits.
Scores
- Congruent RTms
- Average RT on congruent trials (all arrows same direction).
- Lower is better
- Incongruent RTms
- Average RT on incongruent trials (flankers oppose target).
- Lower is better
- Flanker Effectms
- Incongruent RT minus congruent RT. Primary measure of interference cost. Higher values indicate greater susceptibility to distraction.
- Lower is better
- Congruent Accuracy%
- Proportion correct on congruent trials. Expected near ceiling.
- Higher is better
- Incongruent Accuracy%
- Proportion correct on incongruent trials. More sensitive to attentional deficits than congruent accuracy.
- Higher is better
- Overall Accuracy%
- Proportion correct across all trial types.
- Higher is better
Use and evidence
1,472 papers from 2021 to 2025 name this task in their title or abstract, up 17% compared with 2016 to 2020. That ranks it 17 of 582 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 377 |
| 2024 | 309 |
| 2023 | 240 |
| 2022 | 271 |
| 2021 | 275 |
| 2020 | 284 |
| 2019 | 280 |
| 2018 | 271 |
| 2017 | 234 |
| 2016 | 190 |
| 2015 | 206 |
| 2014 | 189 |
| 2013 | 160 |
| 2012 | 143 |
| 2011 | 123 |
| 2010 | 133 |
| 2009 | 80 |
| 2008 | 94 |
| 2007 | 44 |
| 2006 | 51 |
| 2005 | 38 |
| 2004 | 33 |
| 2003 | 21 |
| 2002 | 22 |
| 2001 | 7 |
| 2000 | 13 |
Use grade A
1,000 or more papers from 2021 to 2025.
Evidence grade A
At least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome.
- Papers on test-retest reliability
- 38
- Papers on reliability or validity
- 223
- Registered clinical studies using it as an outcome
- 334
Measured on ConductCognition
Pooled across the studies that feed our platform norms, by device group. A figure needs 50 or more people.
No pooled figure yet.
How the grades work
Use: A is 1,000 or more papers from 2021 to 2025, B 300 to 999, C 100 to 299, D 30 to 99 and E fewer than 30. Evidence: A means at least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome; B, at least 8 test-retest papers, and either 5 registered clinical studies or 150 reliability or validity papers; C, at least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies; D, little published measurement evidence found. The counts measure use. They include every paper that names the task in its title or abstract. Grades describe the published research on this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.39.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: flanker_test, two keys (chance 50%, 24 left and 24 right). Below chance invalidates and not above chance is flagged. One key on 90% of answers invalidates when accuracy is not above chance. No response window; responses under 100 ms follow the timed-test rule.
Why these rules
Accuracy significantly below chance (one-sided exact test, p < .05) cannot come from guessing; it means the response mapping was reversed or the task was not followed (Slick, Sherman and Iverson 1999 treat below-chance forced-choice performance as definite response bias). Chance-level accuracy can be a real result in impaired participants, so it is only flagged. One option on at least 90% of answered trials, when the correct options are balanced and accuracy is not above chance, means the answers did not depend on the items (the task counterpart of long-string responding in surveys; Curran 2016). Missed responses and responses under 100 ms keep the platform's timed-test rule: more than max(3, 25%) missed responses or more than max(2, 20%) responses under 100 ms invalidate, and any is flagged. A response under 100 ms cannot be a reaction to the stimulus.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Congruent trials | 24 | 12 to 48 |
| Incongruent trials | 24 | 12 to 48 |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Timed test: participants need a desktop or laptop with a mouse or trackpad. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Included in these batteries
Each battery runs this test with others in a fixed order, with standard settings.
- Pilot Screening Battery4 tests, 15 minutes per participant
- Executive Control Battery4 tests, 18 minutes per participant
- Language-Minimized Screening Battery8 tests, 30 minutes per participant
- Attention and Impulsivity Battery4 tests, 26 minutes per participant
Cite and describe
Participants completed the Eriksen Flanker Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Eriksen & Eriksen, 1974), with the standard settings (congruent trials: 24; incongruent trials: 24). The main score was flanker effect (incongruent RT minus congruent RT).
Paradigm source: Eriksen & Eriksen (1974).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
Source papers
- Weintraub S, Dikmen SS, Heaton RK, et al. (2013). Cognition assessment using the NIH Toolbox. Neurology, 80(11 Suppl 3):S54-64.Paradigm source
Questions
How long does the Eriksen Flanker Task take?
About 4 to 5 minutes, as listed in the test library.
What device does a participant need?
Timed test: participants need a desktop or laptop with a mouse or trackpad. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Congruent RT, Incongruent RT, Flanker Effect, Congruent Accuracy, Incongruent Accuracy and Overall Accuracy. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Eriksen Flanker Task used in research?
1,472 papers from 2021 to 2025 name it in their title or abstract, up 17% compared with 2016 to 2020. That ranks it 17 of 582 test families in the ConductCognition test census (use grade A). Source: ConductCognition test census 0.39.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Eriksen Flanker Task have?
In the published research, 38 papers report its test-retest reliability and 334 registered clinical studies use it as an outcome (evidence grade A in the ConductCognition test census).
Which settings can a researcher change?
Congruent trials (12 to 48) and incongruent trials (12 to 48). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. English is on every plan, and the other languages come with yearly plans. Have a native speaker read the machine-translated text before launch.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
Every test: the full test list.
Run this test in your next study
Start free with 10 free participants on any test, then use participant credits or a yearly plan.