Attention
Light and Tone Task
Also called: conditioned hallucinations task, conditioned hallucination paradigm, Pavlovian conditioning-induced hallucinations, audiovisual conditioning detection task
Measure how often people report a tone that was not played: a light comes on with noise through headphones, and faint tones grow rarer over 12 rounds.
25-35 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
- 13
- Evidence grade
- C
- Registered clinical studies
- 7
What it measures
Measures how often people report a faint tone that was not played, once they have learned that a light comes with the tone. Over headphones, a light comes on with a burst of noise on each trial, and people say whether they heard a 1 kHz tone in the noise and how sure they are. A threshold step first finds each person's tone levels; then, over 12 rounds, the tones grow fainter and more often absent. The main score is the share of trials with no tone answered Yes. A research measure with no clinical claim.
Constructs
- Perceptual expectation
- Associative learning
- Signal detection
- Perceptual confidence
Research uses
- Psychosis and perception research
- Predictive processing research
- Within-study group comparison
How the paradigm works
The light and tone task measures how often people report a faint tone that was not played, once a light has come to go with the tone. It follows the conditioned hallucinations design of Powers, Mathys and Corlett (2017), as run online by Kafadar and colleagues (2022) and del Rio and colleagues (2024), in which a visual cue is paired with a 1 kHz tone in white noise. It needs headphones and normal hearing. The test starts with the sound setup: the participant turns the device's volume until a steady tone is comfortable, and a six-trial headphone check (Woods, Siegel, Traer and McDermott, 2017) confirms that headphones are in use. By default a failed check ends the test, and the check's result is saved either way.
More about the paradigm
On each trial, after a wait of 500 to 1,000 ms, a white light on a black panel comes on for 1,000 ms together with a burst of white noise of the same length; on a tone trial a 1 kHz tone of 300 ms sits at the burst's center. The light is one steady display per trial, never a flicker. When it goes off the participant answers Yes or No to whether they heard the tone, with no time limit. Six practice trials with clearly audible tones give feedback. A threshold step of 80 trials, two interleaved QUEST staircases (Watson and Pelli, 1983), finds the tone level each person reports 75 percent of the time, and the 50 and 25 percent levels come from a psychometric function fitted to all 80 answers. Then 12 rounds of 30 trials (20 to 30 as a setting) mix tones at the three levels with trials that have no tone: tones at the 75 percent level fall from 18 of 30 in round 1 to 3 in round 12, while trials with no tone rise from 4 to 12. In the rounds the participant also rates how sure they are, from 1 (not sure) to 5 (certain). The light and the noise start together, timed to the screen's frames and the audio clock, so the test runs on desktops and laptops.
Scores
- No-Tone Yes Rate%
- Share of usable answers on trials with no tone that were Yes, over the 12 rounds: the conditioned hallucination rate of the literature.
- Higher means more reports of a tone that was not played
- Confidence, No-Tone Yes Answersscore
- Mean confidence, from 1 (not sure) to 5 (certain), of Yes answers on trials with no tone.
- Informational; empty when there is no such answer
- Confidence, Tone Yes Answersscore
- Mean confidence, from 1 to 5, of Yes answers on trials with a tone.
- Informational
- Yes Rate, 75 Percent Level%
- Share of usable answers that were Yes at the person's 75 percent tone level.
- Near 0.75 when the threshold step held
- Yes Rate, 50 Percent Level%
- Share of usable answers that were Yes at the person's 50 percent tone level.
- Near 0.5 when the threshold step held
- Yes Rate, 25 Percent Level%
- Share of usable answers that were Yes at the person's 25 percent tone level.
- Near 0.25 when the threshold step held
- No-Tone Yes Rate by Round%
- Share of trials with no tone answered Yes in each round, keyed by round.
- Shows when reports of a tone that was not played appear
- d-primed'
- Every tone trial against the trials with no tone, with log-linear corrected rates.
- Higher means tone and no-tone trials were told apart better
- Criterionz
- Response criterion over the same trials.
- Negative leans toward answering Yes
- Tone Level, 75 PercentdB
- The tone's level re the noise, in dB, that the threshold step set for 75 percent Yes answers.
- Lower means a quieter tone was reported; not a hearing level
- Tone Level, 50 PercentdB
- The tone's level re the noise, in dB, read from the fitted function at 50 percent Yes answers.
- Informational
- Tone Level, 25 PercentdB
- The tone's level re the noise, in dB, read from the fitted function at 25 percent Yes answers.
- Informational
- Displays on Time%
- Share of answered trials whose light showed for its planned frames with no frame dropped.
- Under 0.9 is flagged for review
- Median Audio-Visual Offsetms
- Median of the noise heard less the light shown, by the browser's clocks; 0 is planned.
- Informational
- Median Answer Timems
- Median time from when the answers opened, after the light and noise, to the Yes or No.
- Informational; the answer has no time limit
- Anticipationscount
- Answers within 100 ms of the answers opening, which leave the scores.
- Half or more of the answers makes the session invalid
- Completed Trialstrials
- Round trials answered in the scored run.
- Fewer than planned is flagged for review
- Planned Trialstrials
- Round trials the run set out to play.
- Informational
- Headphone Check Passed0/1
- 1 when the headphone check passed (at least 5 of 6 right), 0 when it did not.
- 0 stops the test unless the study set it to continue
- Headphone Check Correctcount
- Headphone check trials answered right, of 6.
- 5 or 6 passes
- Reported Output Delayms
- Output delay the device reported to the browser; empty when the browser does not report it.
- Informational
Use and evidence
13 papers from 2021 to 2025 name this task in their title or abstract, up 30% compared with 2016 to 2020. That ranks it 514 of 582 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 5 |
| 2024 | 3 |
| 2023 | 2 |
| 2022 | 1 |
| 2021 | 2 |
| 2020 | 6 |
| 2019 | 1 |
| 2018 | 1 |
| 2017 | 2 |
| 2016 | 0 |
| 2015 | 0 |
| 2014 | 0 |
| 2013 | 0 |
| 2012 | 0 |
| 2011 | 0 |
| 2010 | 0 |
| 2009 | 1 |
| 2008 | 0 |
| 2007 | 0 |
| 2006 | 0 |
| 2005 | 0 |
| 2004 | 0 |
| 2003 | 0 |
| 2002 | 1 |
| 2001 | 0 |
| 2000 | 0 |
Use grade E
Fewer than 30 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
- 1
- Papers on reliability or validity
- 5
- Registered clinical studies using it as an outcome
- 7
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 8 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Sound setup
- The participant turns the device's volume until a steady 1 kHz tone is comfortable, then takes a 6-trial headphone check (Woods and colleagues, 2017). By default a failed check ends the test; its result is saved either way.
- Trial
- After a wait of 500 to 1,000 ms, a white light on a black panel comes on for 1,000 ms with a burst of white noise of the same length. On a tone trial a 1 kHz tone of 300 ms, with 20 ms ramps, sits at the burst's center. The light is one steady display, never a flicker. When it goes off, the participant answers Yes or No, with no time limit.
- Practice
- 6 trials, 4 with a tone 12 dB below the noise and 2 with none, with feedback for 1,000 ms.
- Threshold step
- 80 trials in two interleaved staircases of 40. Each places the tone by QUEST at its estimate of the level answered Yes 75 percent of the time, starting from 20 and 30 dB below the noise. The 50 and 25 percent levels come from a psychometric function fitted to all 80 answers. Levels stay between 45 and 5 dB below the noise.
- Rounds
- 12 rounds of 30 trials (standard, 20 to 30), at the three levels and with no tone, in an order drawn from the session's seed. Tones at the 75 percent level fall from 18 to 3 per round while trials with no tone rise from 4 to 12. After each Yes or No the participant rates confidence from 1 (not sure) to 5 (certain). A short break follows each round.
- Timing
- The light is drawn on screen frames, and the noise is put on the audio clock to start as the light reaches the screen, with the output delay the browser reports. The browser makes the noise 10 dB below the volume-setting tone.
- Score
- The share of trials with no tone answered Yes, with the confidence of those answers, the Yes rate at each level and in each round, and d-prime and criterion over all trials. Answers under 100 ms leave the score.
Known in the literature as the conditioned hallucinations task. Its scores describe answers in a detection task and support research; the task makes no clinical claim. Levels are relative to the noise and to the volume the participant chose, and headphones differ, so compare results within studies run the same way. The test needs normal hearing and headphones, wired if possible. It is not a hearing test, and no percentile is given.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: light_tone_test from the scored run, a Yes or No to whether a tone was heard, answered after the light and noise with no time limit. Yes on trials with no tone is the measure, so no answer is judged right or wrong. Answers under 100 ms invalidate when they are at least half. A headphone check that stopped the test invalidates; a failed check with the test run anyway, Yes answers that do not rise from no tone to the loudest tones, a tone level at the edge of the levels played, fewer than 90% of trials with the light shown as planned, or a run short of its planned trials is flagged for review.
Why these rules
Reports of a tone that was not played are what the task measures (Powers, Mathys and Corlett 2017), so they are never treated as errors and accuracy is not judged against chance. The sources kept only participants whose Yes answers rose with the tone's level (del Rio and colleagues 2024), and the levels come from each person's threshold step. The answers open once the light and noise have ended and have no time limit, so an answer under 100 ms was pressed before they opened, and only a session made mostly of such answers is invalid. A failed headphone check that stopped the test leaves no trials to score (Woods, Siegel, Traer and McDermott, 2017).
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| When the headphone check fails | Stop the test | Stop the test, Continue the test |
| Trials per round | 30 | 20 to 30 |
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 Light and Tone Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Powers, Mathys and Corlett, 2017; Kafadar et al., 2022), with the standard settings (when the headphone check fails: Stop the test; trials per round: 30). The main score was no-tone yes rate (share of usable answers on trials with no tone that were Yes, over the 12 rounds: the conditioned hallucination rate of the literature).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Powers, A. R., Mathys, C., & Corlett, P. R. (2017). Pavlovian conditioning-induced hallucinations result from overweighting of perceptual priors. Science, 357(6351), 596-600. https://doi.org/10.1126/science.aan3458The design: a visual cue paired with a 1 kHz tone in white noise, each person's detection levels found first, then 12 rounds of 30 trials in which tones at the threshold grow rarer and trials with no tone more common; Yes answers with no tone are the measure, with confidence.
- Kafadar, E., Fisher, V. L., Quagan, B., Hammer, A., Jaeger, H., Mourgues, C., Thomas, R., Chen, L., Imtiaz, A., Sibarium, E., Negreira, A. M., Sarisik, E., Polisetty, V., Benrimoh, D., Sheldon, A. D., Lim, C., Mathys, C., & Powers, A. R. (2022). Conditioned hallucinations and prior overweighting are state-sensitive markers of hallucination susceptibility. Biological Psychiatry, 92(10), 772-780. https://doi.org/10.1016/j.biopsych.2022.05.007The online version: two interleaved 40-trial QUEST staircases for the 75 percent level, the 25 and 50 percent levels from a fitted psychometric function, and confidence from 1 (unsure) to 5 (certain).
- del Rio, M., Kafadar, E., Fisher, V., D'Costa, R., Powers, A., & Ward, J. (2024). The mechanisms underlying conditioning of phantom percepts differ between those with hallucinations and synesthesia. Scientific Reports, 14, 5607. https://doi.org/10.1038/s41598-024-53663-3The online trial: a 300 ms tone with the cue after a 500 to 1,000 ms wait, a fixed ratio of levels in each round, and d-prime with every tone trial against the trials with no tone.
- Watson, A. B., & Pelli, D. G. (1983). QUEST: A Bayesian adaptive psychometric method. Perception & Psychophysics, 33(2), 113-120. https://doi.org/10.3758/BF03202828The staircases of the threshold step.
- 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 before the test.
Source papers
- Powers, Mathys and Corlett (2017): a visual cue paired with a tone in noise, with the share of trials with no tone answered Yes as the measure. Kafadar et al. (2022) and del Rio et al. (2024): the online version, with QUEST thresholds and 12 rounds of 30 trials.Paradigm source, Adults
Questions
How long does the Light and Tone Task take?
About 25 to 35 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?
No-Tone Yes Rate, Confidence, No-Tone Yes Answers, Confidence, Tone Yes Answers, Yes Rate, 75 Percent Level, Yes Rate, 50 Percent Level, Yes Rate, 25 Percent Level, No-Tone Yes Rate by Round, d-prime, Criterion, Tone Level, 75 Percent, Tone Level, 50 Percent, Tone Level, 25 Percent, Displays on Time, Median Audio-Visual Offset, Median Answer Time, Anticipations, Completed Trials, Planned Trials, Headphone Check Passed, Headphone Check Correct and Reported Output Delay. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Light and Tone Task used in research?
13 papers from 2021 to 2025 name it in their title or abstract, up 30% compared with 2016 to 2020. That ranks it 514 of 582 test families in the ConductCognition test census (use grade E). Source: ConductCognition test census 0.39.0, counted 8 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Light and Tone Task have?
In the published research, 1 paper reports its test-retest reliability and 7 registered clinical studies use it as an outcome (evidence grade C in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
When the headphone check fails (Stop the test, Continue the test) and trials per round (20 to 30). 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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