Processing Speed
Intentional Binding Task
Also called: temporal binding task, Libet clock task, sense of agency task, action-effect binding
Measure how a key press and the tone it causes are drawn together in time as participants judge, on a turning clock, when each one happened.
10-12 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
- 140
- Evidence grade
- D
- Registered clinical studies
- 2
What it measures
Measures how a voluntary action and the tone it causes are pulled together in time. Participants watch a clock hand turn, press a key when they like, and point to where the hand was when they pressed or heard a tone. The main score is the overall binding.
Constructs
- Sense of agency
- Time perception
- Action awareness
- Action-outcome binding
Research uses
- Sense of agency research
- Time perception research
- Within-study group comparison
How the paradigm works
The Intentional Binding Task measures how a voluntary action and the event it causes are drawn together in time (Haggard, Clark and Kalogeras, 2002; Moore and Obhi, 2012). A hand turns round a clock once every 2,560 ms, as in the Libet clock (Libet, Gleason, Wright and Pearl, 1983). The participant presses the space bar whenever they like after the hand's first turn, or listens for a tone; when the hand stops and disappears, they click where it was at that moment. The test plays only tones made by the browser, and it needs headphones and normal hearing. Before it starts, the participant sets a comfortable volume and passes a headphone check (Woods, Siegel, Traer and McDermott, 2017).
More about the paradigm
The four parts follow Haggard and colleagues, with the procedure as Ivanof and colleagues (2021) give it: a press alone, judged for the press; a 1 kHz tone alone, 2,500 to 5,000 ms after the hand starts, judged for the tone; and a press that makes the tone sound 250 ms later, judged once for the press and once for the tone. The hand turns on for 1,000 to 2,500 ms after the last event. The parts come in an order drawn from the session's seed, each after one practice trial, with 12 trials each as standard (8 to 30 as a setting); the delay can be 450 or 650 ms instead, the longer delays at which Haggard and colleagues found weaker binding. Each tone is placed on the device's audio clock so that it is heard at its planned time by the device's report, and the delay as played is saved.
A judgment error is the judged minus the actual time of the event, in ms of the hand's turn; errors more than 2.5 standard deviations from a condition's mean are left out (Ivanof and colleagues, 2021). Action binding is the error for presses that caused a tone minus that for presses alone: positive means those presses were judged later. Tone binding is the error for tones caused by a press minus that for tones alone: negative means those tones were judged earlier. The main score, overall binding, is action binding minus tone binding: how much closer together the press and its tone were judged. With this clock speed, Ivanof and colleagues found action binding of 27 ms and tone binding of -60 ms on average, and Galang and colleagues (2021) found both in an online version. Binding is also found when no action is involved (Suzuki, Lush, Seth and Roseboom, 2019), so it measures how the timing of linked events is perceived, not a person's sense of control on its own. Scores support research and do not diagnose.
Scores
- Overall Bindingms
- Action binding minus tone binding: how much closer together the press and its tone were judged than the same events alone.
- Positive means binding; no better direction
- Action Bindingms
- Mean judgment error for presses that caused a tone minus that for presses alone.
- Positive means those presses were judged later
- Tone Bindingms
- Mean judgment error for tones caused by a press minus that for tones alone.
- Negative means those tones were judged earlier
- Judgment Error, Press Alonems
- Mean judged minus actual time of presses that caused nothing.
- Positive means judged later
- Judgment Error, Press with a Tonems
- Mean judged minus actual time of presses that caused a tone.
- Positive means judged later
- Judgment Error, Tone Alonems
- Mean judged minus actual time of tones that sounded on their own.
- Positive means judged later
- Judgment Error, Tone after a Pressms
- Mean judged minus actual time of tones caused by a press.
- Positive means judged later
- Judgment Variabilityms
- Standard deviation of the judgment errors within a condition, averaged over the conditions.
- Lower is more consistent; over 400 ms is flagged for review
- Delay from Press to Tonems
- Median delay from a press to its tone as played, by the device's report.
- Should match the planned delay
- Late Tonescount
- Tones caused by a press that played more than 20 ms after the planned delay.
- Above 0 is flagged for review
- Judgments Keptcount
- Judgments in the condition means.
- Informational
- Judgments Left Outcount
- Judgments more than 2.5 standard deviations from their condition's mean.
- Informational
- Missed Pressescount
- Trials with no press within four turns of the hand.
- With early presses, more than max(3, 25%) of trials makes the session invalid
- Early Pressescount
- Trials ended by a press during the hand's first turn.
- With missed presses, more than max(3, 25%) of trials makes the session invalid
- Presses in the Tone-Alone Partcount
- Presses in the part where a tone sounds on its own.
- 3 or more is flagged for review
- Anticipationscount
- Clicks within 100 ms of the answer clock appearing, not taken as answers.
- Informational
- Test Trialscount
- Test trials in the scored run.
- Informational
- Headphone Check Passedflag
- 1 when the headphone check before the test passed, 0 when it did not and the study's setting ran the test anyway.
- 0 is flagged for review
Use and evidence
140 papers from 2021 to 2025 name this task in their title or abstract, down 19% compared with 2016 to 2020. That ranks it 160 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 39 |
| 2024 | 32 |
| 2023 | 20 |
| 2022 | 14 |
| 2021 | 35 |
| 2020 | 36 |
| 2019 | 41 |
| 2018 | 32 |
| 2017 | 39 |
| 2016 | 24 |
| 2015 | 26 |
| 2014 | 23 |
| 2013 | 23 |
| 2012 | 19 |
| 2011 | 14 |
| 2010 | 8 |
| 2009 | 7 |
| 2008 | 0 |
| 2007 | 5 |
| 2006 | 1 |
| 2005 | 0 |
| 2004 | 2 |
| 2003 | 3 |
| 2002 | 1 |
| 2001 | 0 |
| 2000 | 1 |
Use grade C
100 to 299 papers from 2021 to 2025.
Evidence grade D
Little published measurement evidence found.
- Papers on test-retest reliability
- 0
- Papers on reliability or validity
- 28
- Registered clinical studies using it as an outcome
- 2
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.
- Before the test
- A volume step on a steady 1 kHz tone, then the headphone check of Woods and colleagues (2017): 6 rounds of three 200 Hz tones, passed with at least 5 right. A failed check ends the test unless the study chooses to continue.
- Clock
- A clock 260 px across, marked 5 to 60, with a hand turning once every 2,560 ms from a random start.
- Parts
- Four, in an order drawn from the session's seed: a press alone; a tone alone; and a press that makes a 1 kHz tone of 100 ms sound 250 ms later (standard; 450 or 650 ms), judged once for the press and once for the tone.
- Trial
- The hand stands still for 500 ms, then turns. A press counts after the first turn; a press before it, or none within 4 turns, ends the trial. A tone alone sounds 2,500 to 5,000 ms after the hand starts. The hand turns on for 1,000 to 2,500 ms after the last event, then stops and disappears.
- Answer
- The participant clicks where the hand was, or moves an answer hand with the arrow keys and presses Enter, with no time limit. A click within 100 ms is not taken.
- Trials
- 12 per part (standard, 8 to 30), each part after 1 practice trial: 48 test trials.
- Score
- A judgment error is the judged minus the actual time, in ms of the hand's turn; errors more than 2.5 standard deviations from a part's mean are left out. Overall binding is action binding (press with a tone minus press alone) minus tone binding (tone after a press minus tone alone).
The test plays tones and needs headphones and normal hearing. Binding is a research measure of how the timing of linked events is perceived, best compared between groups and conditions: it also appears for linked events with no action, so it does not show one person's sense of control on its own. 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: intentional_binding_trial from the scored run, one per trial. A judgment has no correct answer, so accuracy is not judged against chance. A trial with no press within four turns of the hand, or with a press in the first turn, has no answer: more than max(3, 25%) such trials invalidate and any is flagged. Answers given under 200 ms on at least half the trials invalidate. No overall binding, judgments spread more than 400 ms within a condition, a caused tone played more than 20 ms late, three or more presses in the tone-alone part and a failed headphone check under the continue setting are flagged. A session the headphone check stopped has no results.
Why these rules
There is no correct option to compare with chance, so accuracy is not judged against chance. Missed presses keep the platform's timed-test rule. An answer under 200 ms is faster than a simple visual reaction, so it cannot reflect the item. Following response-time effort screening for untimed tests (Wise and Kong 2005), the session is invalid only when at least half the answers are that fast. Answers at random over the clock spread about 739 ms, so a much smaller spread shows the hand was followed. Binding falls as the delay from press to tone grows (Haggard et al. 2002), so tones the device played late are flagged. The clock and the tone are timed on the page, so a hidden tab can stop the hand; a percentile is withheld after one. A failed headphone check means the sound may have come from loudspeakers (Woods et al. 2017).
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Trials per condition | 12 | 8 to 30 |
| Delay from press to tone | 250 ms (standard) | 250 ms (standard), 450 ms, 650 ms |
| When the headphone check fails | Stop the test | Stop the test, Continue the test |
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. Needs headphones. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- No percentile. Scores and quality flags only. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Participants completed the Intentional Binding Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Haggard, Clark and Kalogeras, 2002), with the standard settings (trials per condition: 12; delay from press to tone: 250 ms; when the headphone check fails: Stop the test). The main score was overall binding (action binding minus tone binding: how much closer together the press and its tone were judged than the same events alone).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Haggard, P., Clark, S., & Kalogeras, J. (2002). Voluntary action and conscious awareness. Nature Neuroscience, 5(4), 382-385. https://doi.org/10.1038/nn827
- Libet, B., Gleason, C. A., Wright, E. W., & Pearl, D. K. (1983). Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential). Brain, 106(3), 623-642. https://doi.org/10.1093/brain/106.3.623The clock and its speed.
- Moore, J. W., & Obhi, S. S. (2012). Intentional binding and the sense of agency: A review. Consciousness and Cognition, 21(1), 546-561. https://doi.org/10.1016/j.concog.2011.12.002What binding measures and what changes it.
- Ivanof, B. E., Terhune, D. B., Coyle, D., Gottero, M., & Moore, J. W. (2021). Examining the effect of Libet clock stimulus parameters on temporal binding. Psychological Research, 86(3), 937-951. https://doi.org/10.1007/s00426-021-01546-xThe procedure in full, binding at three clock speeds and the rule for leaving out judgments.
- Garaizar, P., Cubillas, C. P., & Matute, H. (2016). A HTML5 open source tool to conduct studies based on Libet's clock paradigm. Scientific Reports, 6, 32689. https://doi.org/10.1038/srep32689The clock in a browser, with no press during the first turn.
- Galang, C. M., Malik, R., Kinley, I., & Obhi, S. S. (2021). Studying sense of agency online: Can intentional binding be observed in uncontrolled online settings? Consciousness and Cognition, 95, 103217. https://doi.org/10.1016/j.concog.2021.103217Binding in an online version.
- Suzuki, K., Lush, P., Seth, A. K., & Roseboom, W. (2019). Intentional binding without intentional action. Psychological Science, 30(6), 842-853. https://doi.org/10.1177/0956797619842191Binding of linked events with no action.
- Woods, K. J. P., Siegel, M. H., Traer, J., & McDermott, J. H. (2017). Headphone screening to facilitate web-based auditory experiments. Attention, Perception, & Psychophysics, 79(7), 2064-2072. https://doi.org/10.3758/s13414-017-1361-2The headphone check.
Source papers
- Haggard, Clark and Kalogeras (2002): the task and its four conditions. Ivanof, Terhune, Coyle, Gottero and Moore (2021): the procedure in full, binding at three clock speeds and the outlier rule. Galang, Malik, Kinley and Obhi (2021): binding in an online version.Paradigm source, Adults
Questions
How long does the Intentional Binding Task take?
About 10 to 12 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. Needs headphones. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Overall Binding, Action Binding, Tone Binding, Judgment Error, Press Alone, Judgment Error, Press with a Tone, Judgment Error, Tone Alone, Judgment Error, Tone after a Press, Judgment Variability, Delay from Press to Tone, Late Tones, Judgments Kept, Judgments Left Out, Missed Presses, Early Presses, Presses in the Tone-Alone Part, Anticipations, Test Trials and Headphone Check Passed. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Intentional Binding Task used in research?
140 papers from 2021 to 2025 name it in their title or abstract, down 19% compared with 2016 to 2020. That ranks it 160 of 395 test families in the ConductCognition test census (use grade C). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Intentional Binding Task have?
In the published research, 0 papers report its test-retest reliability and 2 registered clinical studies use it as an outcome (evidence grade D in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
Trials per condition (8 to 30), delay from press to tone (250 ms (standard), 450 ms, 650 ms) and when the headphone check fails (Stop the test, Continue the test). 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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