Attention
Oddball Target Detection
Also called: oddball task, oddball paradigm, visual oddball, target detection task, three-stimulus oddball
Measure how fast people detect a rare target: a star among frequent circles, scored by response time, hits and false alarms.
6-7 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
- 1,392
- Evidence grade
- A
- Registered clinical studies
- 86
What it measures
Measures how fast and how reliably people detect a rare target. Shapes appear one at a time at a steady pace, and participants press the spacebar only for the rare star. This test records key presses and records no brain activity.
Constructs
- Target detection
- Sustained attention
- Processing speed
Research uses
- Attention and perception research
- Within-study group comparison
- Individual differences in target detection
How the paradigm works
The oddball task measures detection of a rare target in a stream of frequent stimuli. This version is visual and behavioral: shapes appear one at a time at the center of the screen, and participants press the spacebar only for a rare star among frequent circles. It records key presses and response times and records no brain activity. Most oddball studies record EEG, where the rare target elicits the P300, and many use tones; this test plays no sounds.
More about the paradigm
Each shape shows for 150 ms, one every 1,500 ms with up to 100 ms of jitter drawn from the session's seed. The standard session is 200 shapes with 20% targets, 40 targets in about 5 minutes, after 12 practice shapes with feedback. There is always at least one circle between two stars, and a session never has fewer than 36 targets. These values follow the recommended conditions of Duncan et al. (2009). As a setting, a rare square on 10% of trials gives the three-stimulus version (Polich, 2007), and participants do not press for it.
The main score is the median correct response time to targets. Hit rate, false alarm rate, d-prime, response time variability, slowing and change in hit rate across the session, and the sequence effect, the change in response time with the number of standards just before a target, are also reported. Presses under 100 ms are counted as anticipations. Scores support research and do not diagnose.
Scores
- Median Target Response Timems
- Median response time of correct presses to the rare target, from the shape's onset.
- Lower is faster
- Hit Rate%
- Share of targets pressed for at or after 100 ms.
- Higher is better
- False Alarm Rate%
- Share of frequent shapes pressed for at or after 100 ms.
- Lower is better
- d-primed'
- z(hit rate) minus z(false alarm rate), with the log-linear correction.
- Higher means targets were better told apart from the frequent shape
- Mean Target Response Timems
- Mean response time of correct presses to the target.
- Lower is faster
- Response Time SDms
- Standard deviation of the response times of correct presses to the target.
- Lower is steadier
- Response Time Variabilityscore
- Standard deviation divided by the mean of the response times of correct presses to the target.
- Lower is steadier
- Slowing Across the Sessionms/trial
- Slope of target response time on trial number, with at least 10 correct presses.
- Positive values mean slowing across the session
- Hit Rate, First Half%
- Hit rate in the first half of the session.
- Higher is better
- Hit Rate, Second Half%
- Hit rate in the second half of the session.
- Higher is better
- Change in Hit Rate%
- Second-half hit rate minus first-half hit rate.
- Negative values mean more targets were missed later on
- Sequence Effectms/item
- Slope of target response time on the number of standards just before the target, with at least 10 correct presses.
- Negative values mean faster responses after longer runs of standards
- Anticipationscount
- Presses under 100 ms from a shape's onset, on any shape. They count as neither hits nor false alarms.
- Lower is better
- Distractor False Alarm Rate%
- Share of distractors pressed for, when the three-stimulus version runs.
- Lower is better
- Hitscount
- Targets pressed for at or after 100 ms.
- Informational
- Missescount
- Targets with no press.
- Lower is better
- False Alarmscount
- Frequent shapes pressed for at or after 100 ms.
- Lower is better
- Target Trialstrials
- Targets shown in the scored run.
- Informational
- Standard Trialstrials
- Frequent shapes shown in the scored run.
- Informational
- Distractor Trialstrials
- Distractors shown in the scored run.
- Informational
- Planned Trialstrials
- Trials the session planned to show.
- Informational
- Total Trialstrials
- Trials in the scored run.
- Under 90% of the planned trials is invalid
Use and evidence
1,392 papers from 2021 to 2025 name this task in their title or abstract, down 1% compared with 2016 to 2020. That ranks it 18 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 376 |
| 2024 | 253 |
| 2023 | 263 |
| 2022 | 231 |
| 2021 | 269 |
| 2020 | 271 |
| 2019 | 289 |
| 2018 | 303 |
| 2017 | 260 |
| 2016 | 289 |
| 2015 | 287 |
| 2014 | 278 |
| 2013 | 246 |
| 2012 | 222 |
| 2011 | 225 |
| 2010 | 201 |
| 2009 | 226 |
| 2008 | 196 |
| 2007 | 149 |
| 2006 | 141 |
| 2005 | 146 |
| 2004 | 131 |
| 2003 | 115 |
| 2002 | 108 |
| 2001 | 96 |
| 2000 | 91 |
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
- 41
- Papers on reliability or validity
- 296
- Registered clinical studies using it as an outcome
- 86
Note on the counts: most studies record EEG.
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.
- Shapes
- A frequent circle and a rare star at the center of the screen, drawn in one color with equal area, so only the outline tells them apart.
- Display
- Each shape for 150 ms, then a cross until the next shape.
- Pace
- One shape every 1,500 ms (standard; 1,250 to 2,000), moved by up to 100 ms on each trial from the session's seed. A press does not end the trial.
- Trial mix
- 200 trials with 20% targets (standard; 180 to 400 trials and 10% to 30% targets), 40 targets in about 5 minutes. A session never has fewer than 36 targets, so rarer targets add trials.
- Order
- A seeded random order that opens with 3 circles and has at least one circle between two stars.
- Key
- The spacebar, for the star only.
- Practice
- 12 trials with 3 stars, each followed by feedback for 800 ms. No feedback in the test.
- Three-stimulus version
- As a setting, a rare square on 10% of trials takes the place of circles. Participants do not press for it.
This version records key presses and response times and records no brain activity. Most oddball studies record EEG, and many use tones; this one shows shapes only.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: oddball_test from the scored run, press on the target (20% of trials at the standard setting) and withhold on every other shape. Fewer than 90% of the planned trials, a hit rate under 50% or a false alarm rate over 30% invalidates; a hit rate under 75% or a false alarm rate over 10% is flagged and withholds the percentile. Responding mainly on non-targets invalidates; not separating targets is flagged. A run of misses covering half the targets (minimum 8) is flagged and withholds the percentile. Responses under 100 ms follow the timed-test rule.
Why these rules
Responses concentrated on trials that needed none (one-sided Fisher exact test, p < .05) mean the instructions were reversed and invalidate; responses that do not separate the two trial types are flagged. The shapes are large and plainly different, and each target leaves more than a second to answer, so missing many of them or pressing often for the frequent shape means the task was not followed, and the response time then says little about detection. The limits are ConductScience choices: the guideline for this task asks for a measured button press but sets no limits. Responses under 100 ms follow the timed-test rule.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Targets (percent of trials) | 20 | 10 to 30 |
| Number of trials | 200 | 180 to 400 |
| Time between shapes (ms) | 1,500 | 1,250 to 2,000 |
| Add a rare distractor | Off | On or off |
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 Oddball Target Detection task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Squires, Squires and Hillyard, 1975; Duncan et al., 2009), with the standard settings (targets (percent of trials): 20; number of trials: 200; time between shapes (ms): 1,500; add a rare distractor: Off). The main score was median target response time (median response time of correct presses to the rare target, from the shape's onset).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Duncan, C. C., Barry, R. J., Connolly, J. F., Fischer, C., Michie, P. T., Näätänen, R., Polich, J., Reinvang, I., & Van Petten, C. (2009). Event-related potentials in clinical research: Guidelines for eliciting, recording, and quantifying mismatch negativity, P300, and N400. Clinical Neurophysiology, 120(11), 1883-1908. https://doi.org/10.1016/j.clinph.2009.07.045Display time, interval, target share, the button press and the minimum number of targets.
- Squires, N. K., Squires, K. C., & Hillyard, S. A. (1975). Two varieties of long-latency positive waves evoked by unpredictable auditory stimuli in man. Electroencephalography and Clinical Neurophysiology, 38(4), 387-401. https://doi.org/10.1016/0013-4694(75)90263-1
- Polich, J. (2007). Updating P300: An integrative theory of P3a and P3b. Clinical Neurophysiology, 118(10), 2128-2148. https://doi.org/10.1016/j.clinph.2007.04.019The two-stimulus and three-stimulus versions, and sequences defined by the standards before a target.
- Squires, K. C., Wickens, C., Squires, N. K., & Donchin, E. (1976). The effect of stimulus sequence on the waveform of the cortical event-related potential. Science, 193(4258), 1142-1146. https://doi.org/10.1126/science.959831The sequence effect.
- Polich, J., & Bondurant, T. (1997). P300 sequence effects, probability, and interstimulus interval. Physiology & Behavior, 61(6), 843-849. https://doi.org/10.1016/S0031-9384(96)00564-1The sequence effect at different target shares and intervals.
- Fjell, A. M., Walhovd, K. B., Fischl, B., & Reinvang, I. (2007). Cognitive function, P3a/P3b brain potentials, and cortical thickness in aging. Human Brain Mapping, 28(11), 1098-1116. https://doi.org/10.1002/hbm.20335A visual three-stimulus version with 10% targets and 10% distractors.
- Hautus, M. J. (1995). Corrections for extreme proportions and their biasing effects on estimated values of d'. Behavior Research Methods, Instruments, & Computers, 27(1), 46-51. https://doi.org/10.3758/BF03203619
Source papers
- Duncan CC, Barry RJ, Connolly JF, Fischer C, Michie PT, Näätänen R, Polich J, Reinvang I, Van Petten C (2009). Event-related potentials in clinical research: guidelines for eliciting, recording, and quantifying mismatch negativity, P300, and N400. Clinical Neurophysiology, 120(11):1883-1908.Paradigm source, Adults
Questions
How long does the Oddball Target Detection take?
About 6 to 7 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?
Median Target Response Time, Hit Rate, False Alarm Rate, d-prime, Mean Target Response Time, Response Time SD, Response Time Variability, Slowing Across the Session, Hit Rate, First Half, Hit Rate, Second Half, Change in Hit Rate, Sequence Effect, Anticipations, Distractor False Alarm Rate, Hits, Misses, False Alarms, Target Trials, Standard Trials, Distractor Trials, Planned Trials and Total Trials. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Oddball Target Detection used in research?
1,392 papers from 2021 to 2025 name it in their title or abstract, down 1% compared with 2016 to 2020. That ranks it 18 of 395 test families in the ConductCognition test census (use grade A). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Oddball Target Detection have?
In the published research, 41 papers report its test-retest reliability and 86 registered clinical studies use it as an outcome (evidence grade A in the ConductCognition test census).
Which settings can a researcher change?
Targets (percent of trials) (10 to 30), number of trials (180 to 400), time between shapes (ms) (1,250 to 2,000) and add a rare distractor (On or off). 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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