Executive Function
Spatial Stroop Task
Also called: spatial Stroop effect, arrow Stroop task, direction Stroop, spatial interference task, spatial conflict task
Measure spatial conflict: how much slower people name the way an arrow points when it points away from its side of the screen.
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. Preview any test free after you sign up.
- Papers, 2021 to 2025
- 90
- Evidence grade
- C
- Registered clinical studies
- 3
What it measures
Measures interference from where an arrow appears when only the way it points matters. An arrow pointing left or right appears to the left or right of a central cross. Participants press F when it points left and J when it points right, ignoring its side. The score is the slowing when the arrow points away from its own side.
Constructs
- Interference control
- Spatial conflict resolution
- Selective attention
Research uses
- Cognitive control and conflict research
- Aging research
- Neurological and psychiatric research
How the paradigm works
The Spatial Stroop Task measures interference between where a stimulus is and what it means when both are about space. After a cross alone for 500 ms, an arrow pointing left or right appears 220 px to the left or right of the cross. Participants press F when the arrow points left and J when it points right, as quickly and accurately as they can; the arrow stays until an answer or 1,500 ms. Its side is irrelevant: on congruent trials the arrow points toward its own side, and on incongruent trials it points away. The keys follow the arrow's direction in every session.
More about the paradigm
Each session has 160 trials (standard; 80 to 240) in a seeded order, half congruent and half incongruent, with each direction on each side equally often, after 8 practice trials with feedback, in about 4 minutes. Desktop and laptop only.
The main score is the congruency effect: mean correct response time on incongruent trials minus congruent trials, in ms; lower means less interference from the arrow's side. The difference of the medians, response times and accuracy in each condition, and the accuracy cost are also reported. The task has one rule throughout: the arrow's side is never the rule and no cue switches between rules, so it gives no switching cost. Scores support research and do not diagnose.
Scores
- Congruency Effectms
- Mean correct response time on incongruent trials minus congruent trials.
- Lower means less interference from the arrow's side; positive values are typical
- Congruent RTms
- Mean correct response time when the arrow pointed toward its own side.
- Informational
- Incongruent RTms
- Mean correct response time when the arrow pointed away from its side.
- Informational
- Congruency Effect (Medians)ms
- Median correct response time on incongruent trials minus congruent trials, less sensitive to slow outliers.
- Lower means less interference
- Mean Correct RTms
- Mean response time over all correct trials.
- Lower is faster
- Accuracy%
- Share of trials answered correctly; a trial with no answer counts as wrong.
- Higher is better
- Congruent Accuracy%
- Share correct when the arrow pointed toward its own side.
- Informational
- Incongruent Accuracy%
- Share correct when the arrow pointed away from its side.
- Informational
- Accuracy Cost%
- Congruent accuracy minus incongruent accuracy.
- Lower means fewer extra errors when the arrow points away
- Congruent Trials Usedtrials
- Correct congruent trials at or after 100 ms that the effect uses.
- Fewer than 20 in either condition is flagged for review
- Incongruent Trials Usedtrials
- Correct incongruent trials at or after 100 ms that the effect uses.
- Fewer than 20 in either condition is flagged for review
- Anticipationscount
- Answers within 100 ms of the arrow.
- Many invalidate the session
- Missed Trialscount
- Trials with no answer within 1,500 ms.
- Informational
- Total Trialstrials
- Scored trials in the run.
- Informational
Use and evidence
90 papers from 2021 to 2025 name this task in their title or abstract, up 61% compared with 2016 to 2020. That ranks it 196 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 23 |
| 2024 | 28 |
| 2023 | 20 |
| 2022 | 16 |
| 2021 | 3 |
| 2020 | 11 |
| 2019 | 4 |
| 2018 | 16 |
| 2017 | 17 |
| 2016 | 8 |
| 2015 | 8 |
| 2014 | 15 |
| 2013 | 12 |
| 2012 | 3 |
| 2011 | 5 |
| 2010 | 6 |
| 2009 | 10 |
| 2008 | 2 |
| 2007 | 3 |
| 2006 | 4 |
| 2005 | 4 |
| 2004 | 2 |
| 2003 | 1 |
| 2002 | 0 |
| 2001 | 2 |
| 2000 | 1 |
Use grade D
30 to 99 papers from 2021 to 2025.
Evidence grade C
At least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies.
- Papers on test-retest reliability
- 0
- Papers on reliability or validity
- 16
- Registered clinical studies using it as an outcome
- 3
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 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Display
- On a dark panel: a cross for 500 ms, then an arrow pointing left or right, 220 px left or right of the cross.
- Arrow
- 84 by 44 px. It stays until an answer or 1,500 ms.
- Keys
- F if the arrow points left and J if it points right, in every session. The arrow's side is never the rule.
- Trial mix
- 160 trials (standard; 80 to 240) in a seeded order: half congruent, pointing toward its own side, and half incongruent, with each direction on each side equally often.
- Practice
- 8 trials with feedback for 800 ms.
- Score
- Mean correct response time on incongruent trials minus congruent trials. Answers under 100 ms count as anticipations and leave the means.
This version keeps one rule throughout. No cue switches between answering the arrow's direction and its side, so it reports no switching cost.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: spatial_stroop_test from the scored run, F or J (chance 50%, half of each) within 1,500 ms, correctness from the recorded direction of the arrow. Below chance invalidates and not above chance is flagged. One key on 90% of answers invalidates when accuracy is not above chance. Missed responses and responses under 100 ms follow the timed-test rule. Fewer than 20 correct trials in either condition is flagged and withholds the percentile.
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. The effect is a difference between two means, so it needs enough correct trials in each condition; the limit of 20 is a ConductScience choice.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Number of trials | 160 | 80 to 240 |
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.
Cite and describe
Participants completed the Spatial Stroop Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Lu and Proctor, 1995; Funes, Lupiáñez and Milliken, 2007), with the standard settings (number of trials: 160). The main score was congruency effect (mean correct response time on incongruent trials minus congruent trials).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- 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
- Funes, M. J., Lupiáñez, J., & Milliken, B. (2007). Separate mechanisms recruited by exogenous and endogenous spatial cues: Evidence from a spatial Stroop paradigm. Journal of Experimental Psychology: Human Perception and Performance, 33(2), 348-362. https://doi.org/10.1037/0096-1523.33.2.348An arrow left or right of fixation whose direction is named.
- Marotta, A., Román-Caballero, R., & Lupiáñez, J. (2018). Arrows don't look at you: Qualitatively different attentional mechanisms triggered by gaze and arrows. Psychonomic Bulletin & Review, 25(6), 2254-2259. https://doi.org/10.3758/s13423-018-1457-2Faster answers when an arrow points toward its own side of fixation.
- Narganes-Pineda, C., Chica, A. B., Lupiáñez, J., & Marotta, A. (2023). Explicit vs. implicit spatial processing in arrow vs. eye-gaze spatial congruency effects. Psychological Research, 87(1), 242-259. https://doi.org/10.1007/s00426-022-01659-xTwo keys for left and right, half congruent and half incongruent trials, and mean correct response times.
- Viviani, G., Visalli, A., Finos, L., Vallesi, A., & Ambrosini, E. (2024). A comparison between different variants of the spatial Stroop task: The influence of analytic flexibility on Stroop effect estimates and reliability. Behavior Research Methods, 56(2), 934-951. https://doi.org/10.3758/s13428-023-02091-8How versions of the task and analysis choices change the effect and its reliability.
Source papers
- Lu C-H, Proctor RW (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.Paradigm source, Adults
Questions
How long does the Spatial Stroop 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?
Congruency Effect, Congruent RT, Incongruent RT, Congruency Effect (Medians), Mean Correct RT, Accuracy, Congruent Accuracy, Incongruent Accuracy, Accuracy Cost, Congruent Trials Used, Incongruent Trials Used, Anticipations, Missed Trials and Total Trials. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Spatial Stroop Task used in research?
90 papers from 2021 to 2025 name it in their title or abstract, up 61% compared with 2016 to 2020. That ranks it 196 of 395 test families in the ConductCognition test census (use grade D). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Spatial Stroop Task have?
In the published research, 0 papers report its test-retest reliability and 3 registered clinical studies use it as an outcome (evidence grade C in the ConductCognition test census).
Which settings can a researcher change?
Number of trials (80 to 240). 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.
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