Spatial Cognition
Hand Laterality Task
Also called: hand laterality judgment task, left/right judgment task, left-right hand judgment, hand mental rotation, hand rotation task, implicit motor imagery task
Measure motor imagery with timed left or right judgments of drawn hands, seen from the back or the palm and turned to eight angles.
6-8 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
- 77
- Evidence grade
- C
- Registered clinical studies
- 16
What it measures
Measures how quickly people judge whether a pictured hand is a left or a right hand, a task solved by imagining one's own hand moving. Drawings of hands, seen from the back or the palm, are turned to eight angles.
Constructs
- Motor imagery
- Mental rotation of body parts
- Body representation
- Left-right discrimination
Research uses
- Motor imagery research
- Chronic pain research
- Stroke and rehabilitation research
- Aging and development studies
How the paradigm works
The hand laterality task measures how quickly and accurately people tell a left hand from a right hand when the hand is turned. Each trial shows a drawing of one hand, seen from the back or from the palm and turned clockwise by 0 to 315 degrees in steps of 45. Participants press F with the left index finger for a left hand and J with the right index finger for a right hand. The hand stays until a key press or 5 seconds, after an 800 ms fixation cross.
More about the paradigm
Sekiyama (1982) and Parsons (1987, 1994) found that people solve this task by imagining their own hand moving into the pictured position: times rise with the turn, and turns the hand cannot easily make take longer. A lateral turn points the fingers away from the body, as when a right hand is turned clockwise, and a medial turn points them toward it. Showing backs and palms together brings out this difference (ter Horst, van Lier and Steenbergen 2010). The procedure follows the online version of Moreno-Verdú and colleagues (2025): eight turns, two views, both index fingers and an 800 ms cross. The 32 pictures are drawn by the task's own code. The standard session has two blocks of 64 trials, 128 in all, after 16 practice trials with feedback, in about 7 minutes; a setting gives one or three blocks.
The main score is the mean time of correct answers, from answers of 300 to 3,000 ms, the bounds Moreno-Verdú and colleagues used. Accuracy is the share of all trials answered correctly. The biomechanical effect is the mean time on lateral turns of 45, 90 and 135 degrees minus the mean time on medial turns of the same sizes; a positive value is the sign that the judgment was made by imagining one's own hand. It is reported for both views together and for each view, and it is usually larger for palms. Times and accuracy by view, by hand and by angle are also reported. Scores support research and do not diagnose.
Scores
- Mean Correct RTms
- Mean time of correct answers from 300 to 3,000 ms, over every picture.
- Lower is faster
- Accuracy%
- Share of test trials answered correctly. Hands not answered within 5 seconds count as errors.
- Higher is better
- Biomechanical Effectms
- Mean correct time on lateral turns minus medial turns of 45, 90 and 135 degrees, both views together.
- Positive when awkward turns take longer, the sign of motor imagery
- Biomechanical Effect, Palmms
- The same difference for hands seen from the palm, where it is usually largest.
- Positive when awkward turns take longer
- Biomechanical Effect, Backms
- The same difference for hands seen from the back.
- Positive when awkward turns take longer
- Palm View RTms
- Mean correct time for hands seen from the palm; the back view is also reported.
- Lower is faster
- RT at 180 Degreesms
- Mean correct time for upside-down hands; times at 0, 45, 90 and 135 degrees either way are also reported.
- Lower is faster
- Missed Handscount
- Test hands not answered within 5 seconds.
- Lower is better
- Anticipationscount
- Answers given less than 100 ms after the hand appeared.
- Lower is better
- Slow Correct Answerscount
- Correct answers given after 3,000 ms, left out of the times.
- Informational
Use and evidence
77 papers from 2021 to 2025 name this task in their title or abstract, up 4% compared with 2016 to 2020. That ranks it 211 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 18 |
| 2024 | 16 |
| 2023 | 11 |
| 2022 | 13 |
| 2021 | 19 |
| 2020 | 13 |
| 2019 | 17 |
| 2018 | 11 |
| 2017 | 14 |
| 2016 | 19 |
| 2015 | 17 |
| 2014 | 10 |
| 2013 | 10 |
| 2012 | 8 |
| 2011 | 4 |
| 2010 | 5 |
| 2009 | 5 |
| 2008 | 2 |
| 2007 | 0 |
| 2006 | 2 |
| 2005 | 4 |
| 2004 | 0 |
| 2003 | 0 |
| 2002 | 3 |
| 2001 | 1 |
| 2000 | 0 |
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
- 2
- Papers on reliability or validity
- 7
- Registered clinical studies using it as an outcome
- 16
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 2 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Pictures
- Drawings of a left or a right hand, made by the task's own code and seen from the back (nails and knuckles) or the palm (its creases). A left hand is the mirror image of the right one.
- Turns
- Each picture is turned clockwise by 0, 45, 90, 135, 180, 225, 270 or 315 degrees: 2 hands, 2 views and 8 turns make 32 pictures.
- Trial
- An 800 ms fixation cross, then the hand until a key press or 5,000 ms. F answers left hand and J right hand, each pressed with the index finger of that hand.
- Blocks
- Two blocks of 64 trials (standard; one to three). Each block shows every picture twice, in two shuffled rounds, and never the same picture twice in a row.
- Practice
- 16 trials with feedback: every turn once in each view, with one left and one right hand at each turn.
- Scoring
- The mean time of correct answers from 300 to 3,000 ms. The biomechanical effect is the mean time on lateral turns, which point the fingers away from the body, minus medial turns, which point them toward it.
The hands are drawn by this task's own code; no photograph or published picture set is used. Published times come from other pictures and keys and are not applied as norms. The scores support research and do not diagnose.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: hand_laterality_trial test rows from the scored run, a left or a right hand (chance 50%, half of each) within 5 s. 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.
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 |
|---|---|---|
| Blocks of 64 trials | 2 | 1 to 3 |
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 Hand Laterality Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Sekiyama K, 1982; Parsons LM, 1987; Parsons LM, 1994), with the standard settings (blocks of 64 trials: 2). The main score was mean correct RT (mean time of correct answers from 300 to 3,000 ms, over every picture).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Sekiyama, K. (1982). Kinesthetic aspects of mental representations in the identification of left and right hands. Perception & Psychophysics, 32(2), 89-95. https://doi.org/10.3758/BF03204268
- Parsons, L. M. (1994). Temporal and kinematic properties of motor behavior reflected in mentally simulated action. Journal of Experimental Psychology: Human Perception and Performance, 20(4), 709-730. https://doi.org/10.1037/0096-1523.20.4.709Longer times for turns the hand cannot easily make.
- ter Horst, A. C., van Lier, R., & Steenbergen, B. (2010). Mental rotation task of hands: Differential influence number of rotational axes. Experimental Brain Research, 203(2), 347-354. https://doi.org/10.1007/s00221-010-2235-1Back and palm views together, and the lateral and medial turns.
- Moreno-Verdú, M., McAteer, S. M., Waltzing, B. M., Van Caenegem, E. E., & Hardwick, R. M. (2025). Development and validation of an open-source hand laterality judgement task for in-person and online studies. Neuroscience, 572, 93-107. https://doi.org/10.1016/j.neuroscience.2025.02.056The online procedure: eight turns, two views, both index fingers, the 800 ms cross and the 300 to 3,000 ms bounds.
- Moreno-Verdú, M., Waltzing, B. M., Van Caenegem, E. E., Czilczer, C., Boidequin, L. F., Truong, C., Dahm, S. F., & Hardwick, R. M. (2026). A comprehensive, open-source battery of movement imagery ability tests: Development and psychometric properties. Behavior Research Methods, 58(5). https://doi.org/10.3758/s13428-026-03002-3How stable the time and accuracy are a week apart.
Source papers
- Sekiyama K (1982). Kinesthetic aspects of mental representations in the identification of left and right hands. Perception & Psychophysics, 32(2):89-95.N 15, Undergraduates
- ter Horst AC, van Lier R, Steenbergen B (2010). Mental rotation task of hands: differential influence number of rotational axes. Experimental Brain Research, 203(2):347-354.N 12, Young adults
- Moreno-Verdú M, McAteer SM, Waltzing BM, Van Caenegem EE, Hardwick RM (2025). Development and validation of an open-source hand laterality judgement task for in-person and online studies. Neuroscience, 572:93-107.N 100, Adults
- Moreno-Verdú M, Waltzing BM, Van Caenegem EE, Czilczer C, Boidequin LF, Truong C, Dahm SF, Hardwick RM (2026). A comprehensive, open-source battery of movement imagery ability tests: development and psychometric properties. Behavior Research Methods, 58(5).N 122, Adults
Questions
How long does the Hand Laterality Task take?
About 6 to 8 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?
Mean Correct RT, Accuracy, Biomechanical Effect, Biomechanical Effect, Palm, Biomechanical Effect, Back, Palm View RT, RT at 180 Degrees, Missed Hands, Anticipations and Slow Correct Answers. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Hand Laterality Task used in research?
77 papers from 2021 to 2025 name it in their title or abstract, up 4% compared with 2016 to 2020. That ranks it 211 of 395 test families in the ConductCognition test census (use grade D). Source: ConductCognition test census 0.14.0, counted 2 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Hand Laterality Task have?
In the published research, 2 papers report its test-retest reliability and 16 registered clinical studies use it as an outcome (evidence grade C in the ConductCognition test census).
Which settings can a researcher change?
Blocks of 64 trials (1 to 3). 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.
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