Attention
Repetition Blindness Task
Also called: repetition blindness paradigm, RB, RSVP repetition blindness, repetition blindness for words, token individuation, rapid serial visual presentation of words
Measure repetition blindness: in a rapid stream of six words, the second copy of a repeated word is often missed, read across a group.
8-11 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
- 15
- Evidence grade
- D
- Registered clinical studies
- 0
What it measures
Measures repetition blindness: in a rapid stream of words, people often miss the second copy of a word shown twice. Six English words flash one after another at about eight a second, and participants type the words they saw. The effect is read across a group.
Constructs
- Visual attention
- Token individuation
- Visual word recognition
Research uses
- Attention and word recognition research, at the group level
- Rapid serial visual presentation research
- Within-study group comparison
How the paradigm works
The repetition blindness task measures repetition blindness: when words are shown one after another at about eight a second, people often fail to report the second copy of a word shown twice, though they report a different word in the same place (Kanwisher, 1987). Kanwisher explained it as recognizing the word's type without setting up a second token for its second copy.
More about the paradigm
After SPACEBAR, a row of asterisks shows for 500 ms, then six English words, each for 117 ms in whole screen frames with no gap (the standard; 150 or 183 ms is a setting fixed before the session), then a row of percent signs for 250 ms. The participant then types the words seen, in any order, typing a word twice when it came twice, as in the list recall of Kanwisher and Potter (1990). On a repeated list one word is shown in places 2 and 4, or 3 and 5; on an unrepeated list the first of those places shows another word of the same length, the control of Kanwisher (1987). Each of 32 lists is repeated or unrepeated by the session's seed, half of each pair of places each way. Three practice lists with feedback come first, the first at 250 ms a word. The primary score is the share of unrepeated lists with both critical words typed minus the share of repeated lists with the repeated word typed twice, the joint report Harris and colleagues (2021) describe as the most common measure. One person's difference is noisy, so it is read across a group.
Scores
- Repetition Blindness%
- Share of unrepeated lists with both critical words typed minus share of repeated lists with the repeated word typed twice.
- Positive values mean the second copy was missed more often; read across a group
- Both Copies Typed%
- Share of repeated lists with the repeated word typed twice.
- Higher means fewer second copies missed
- Both Critical Words Typed%
- Share of unrepeated lists with both critical words typed.
- Higher is better
- Repeated Word Typed%
- Share of repeated lists with the repeated word typed at least once.
- Higher is better
- Second Critical Word Typed%
- Share of unrepeated lists with the word in the second critical place typed.
- Higher is better
- First Critical Word Typed%
- Share of unrepeated lists with the word in the first critical place typed.
- Higher is better
- Other Words Typed%
- Share of the four other words of each list that were typed.
- Higher is better
- Words Typed Too Oftencount
- Lists with a word shown once but typed more than once.
- Lower is better
- Words From Outside the Listscount
- Entries that name no word of any list shown so far.
- Lower is better
- Words From Earlier Listscount
- Entries that name a word of an earlier list.
- Lower is better
- List Words Typedcount
- Entries that name a word of their own list, each time typed.
- Informational
- Paste Attemptscount
- Blocked attempts to paste into the report.
- Any is flagged
- Word Durationms
- Median measured time each word was on the screen.
- Informational; the standard plan is 117 ms
- Frame Intervalms
- Median time between screen frames, about 16.7 ms on a 60 Hz screen.
- Informational
- Long Words%
- Share of words that stayed a frame or more too long, a sign of missed screen frames.
- Over 10% is flagged
- Liststrials
- Test lists with a report in the scored run.
- Informational
- Repeated Liststrials
- Lists shown with one word twice.
- Informational
- Unrepeated Liststrials
- Lists shown with six different words.
- Informational
- Session in Another Language0/1
- 1 when the session ran in a language other than English; the words are English in every session.
- 1 is flagged for review
Use and evidence
15 papers from 2021 to 2025 name this task in their title or abstract, down 32% compared with 2016 to 2020. That ranks it 431 of 495 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 3 |
| 2024 | 1 |
| 2023 | 2 |
| 2022 | 5 |
| 2021 | 4 |
| 2020 | 1 |
| 2019 | 4 |
| 2018 | 6 |
| 2017 | 4 |
| 2016 | 7 |
| 2015 | 9 |
| 2014 | 9 |
| 2013 | 9 |
| 2012 | 13 |
| 2011 | 10 |
| 2010 | 26 |
| 2009 | 12 |
| 2008 | 12 |
| 2007 | 7 |
| 2006 | 8 |
| 2005 | 17 |
| 2004 | 18 |
| 2003 | 6 |
| 2002 | 13 |
| 2001 | 12 |
| 2000 | 7 |
Use grade E
Fewer than 30 papers from 2021 to 2025.
Evidence grade D
Little published measurement evidence found.
- Papers on test-retest reliability
- 0
- Papers on reliability or validity
- 5
- Registered clinical studies using it as an outcome
- 0
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 0.22.0, counted 2 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Display
- On a dark panel, each word in capitals, 44 px, in the middle, one after another in the same place with no gap.
- Stream
- After SPACEBAR, a row of six asterisks for 500 ms, six words for 117 ms each in whole screen frames, seven frames of a 60 Hz screen (standard; 150 or 183 ms as a setting), then a row of six percent signs for 250 ms.
- Lists
- 32 lists of six English words, each word used once in the session. On a repeated list one word is shown in two places with one word between them, places 2 and 4 in half the lists and 3 and 5 in the other half; on an unrepeated list the first of those places shows another word of the same length.
- Conditions
- Each list is repeated or unrepeated by the session's seed, half of each pair of places each way, so across a group every list counts in both. No more than three lists of one kind in a row, and a rest after 16 lists.
- Report
- After each list the participant types the words seen, one per entry, in any order, typing a word twice when it came twice, then clicks Done. Entries are read by rule: case, accents and articles are ignored, and one wrong, missing, extra or swapped letter is accepted in words of 4 or more letters unless the entry is another English word.
- Practice
- 3 lists, the first at 250 ms a word, each followed by its words and, after a repeated list, which word came twice.
- Score
- The share of unrepeated lists with both critical words typed minus the share of repeated lists with the repeated word typed twice. Also each critical word of the unrepeated lists, and the four other words.
The effect is read across a group: it is a difference between two shares of 16 lists each, which is noisy in one person. Each word stays a whole number of screen frames, seven on a 60 Hz screen, and each list saves how long every display was shown; sessions whose words stayed a frame or more too long more than a tenth of the time are flagged, since a slower stream shows less repetition blindness. The words are English in every session, so a session in another language is flagged for review. 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: repetition_blindness_test, the typed report after each test list of the scored run (practice excluded). Typed recall has no chance level and no response is required, so accuracy is not judged against chance. Typing no word of any list is flagged. Typing more words from outside the lists than list words, with at least 6 of them, is flagged. Blocked paste attempts are flagged. Words shown a frame or more too long more than 10% of the time are flagged. A session run in another language is flagged. A hidden tab withholds the percentile.
Why these rules
Typed recall has no options to guess between, and typing little can be a real result at 117 ms a word, so it is flagged for review rather than invalidated. Many words from outside the lists suggest the lists were not followed, and pasting could bring in words from elsewhere. Repetition blindness falls as the stream slows (Kanwisher, 1987), so a stream that missed screen frames is flagged; the 10% limit is a ConductScience choice. The word lists are English. A session run in another language shows English words to a participant who may not read English fluently, so it is flagged for review. A hidden tab lets the study, delay or response timers run without the participant, so a percentile is withheld after one.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Time per word (ms) | 117 (standard) | 117 (standard), 150, 183 |
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
- Instructions and screens: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. Words and sentences: English.
- 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 Repetition Blindness Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Kanwisher, 1987; Kanwisher and Potter, 1990), with the standard settings (time per word (ms): 117). The main score was repetition blindness (share of unrepeated lists with both critical words typed minus share of repeated lists with the repeated word typed twice).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Kanwisher, N. G. (1987). Repetition blindness: Type recognition without token individuation. Cognition, 27(2), 117-143. https://doi.org/10.1016/0010-0277(87)90016-3The effect: at 117 ms a word, the second copy of a repeated word was recalled far less often than the same word after a different one.
- Kanwisher, N. G., & Potter, M. C. (1990). Repetition blindness: Levels of processing. Journal of Experimental Psychology: Human Perception and Performance, 16(1), 30-47. https://doi.org/10.1037/0096-1523.16.1.30Lists of six unrelated words with the critical words in places 2 and 4 or 3 and 5, recalled after each list.
- Harris, I. M., Hayward, W. G., Seet, M. S., & Andrews, S. (2021). Repetition blindness for words and pictures: A failure to form stable type representations? Memory & Cognition, 49(6), 1153-1162. https://doi.org/10.3758/s13421-021-01146-5Repetition blindness for words with each item seen once, scored by the report of both critical items.
Source papers
- Kanwisher (1987), Cognition, 27(2), 117-143, and Kanwisher and Potter (1990), Journal of Experimental Psychology: Human Perception and Performance, 16(1), 30-47: spoken recall of sentences and lists.Paradigm source, Adults
Questions
How long does the Repetition Blindness Task take?
About 8 to 11 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?
Repetition Blindness, Both Copies Typed, Both Critical Words Typed, Repeated Word Typed, Second Critical Word Typed, First Critical Word Typed, Other Words Typed, Words Typed Too Often, Words From Outside the Lists, Words From Earlier Lists, List Words Typed, Paste Attempts, Word Duration, Frame Interval, Long Words, Lists, Repeated Lists, Unrepeated Lists and Session in Another Language. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Repetition Blindness Task used in research?
15 papers from 2021 to 2025 name it in their title or abstract, down 32% compared with 2016 to 2020. That ranks it 431 of 495 test families in the ConductCognition test census (use grade E). Source: ConductCognition test census 0.22.0, counted 2 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Repetition Blindness Task have?
In the published research, 0 papers report its test-retest reliability and 0 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?
Time per word (ms) (117 (standard), 150, 183). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
The instructions and screens are in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. The words and sentences stay in English, so sessions in other languages are flagged for review. 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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