Processing Speed
Paced Visual Serial Addition Test
Also called: PVSAT, paced serial addition task
Measure information processing speed as participants add each digit to the one before it at a fixed pace of 3 or 2 seconds.
5-7 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
- 397
- Evidence grade
- A
- Registered clinical studies
- 337
What it measures
Measures information processing speed and working memory. Digits appear one at a time at a fixed pace, and participants type the sum of each digit and the one before it before the next digit appears. This is the visual version: digits are shown and sums are typed.
Constructs
- Information processing speed
- Working memory
- Sustained attention
Research uses
- Information processing research in multiple sclerosis and brain injury studies
- Performance across a session, from the first to the last third
- Within-study group comparison
How the paradigm works
The Paced Visual Serial Addition Test is the visual version of Gronwall's paced auditory serial addition task. Digits from 1 to 9 appear one at a time, one every 3 seconds by default or every 2 seconds, and each stays on screen for 1 second. Participants add each new digit to the one just before it and type the sum before the next digit appears. The test has 61 digits, so 60 sums. This version shows the digits and takes typed sums; it does not play spoken digits or record spoken answers.
More about the paradigm
The digit sequences are generated for each session from its random seed by a fixed rule: each digit appears about equally often, no digit appears twice in a row, no two sums in a row are the same, and each third of the test has the same number of two-digit sums. Practice has 10 sums at one digit every 4 seconds, with feedback after each, and runs once more with new digits if fewer than 5 are correct.
The main score is the number of correct sums. Dyads count correct sums that directly follow another correct sum; a low share of dyads among correct sums suggests that items were skipped to add alternate pairs. Omissions are sums not typed in time, and correct sums in each third show whether performance holds up across the test. Sums typed less than 100 ms after a digit appears count as anticipations, not correct answers. Scores support research and do not diagnose.
Scores
- Total Correctcount
- Correct sums out of 60.
- Higher is better
- Percent Correct%
- Correct sums as a percentage of the items shown.
- Higher is better
- Dyadscount
- Correct sums that directly follow another correct sum.
- Higher is better
- Percent Dyads%
- Dyads as a percentage of correct sums.
- Lower suggests alternate items were skipped
- Omissionscount
- Items with no sum typed before the next digit.
- Lower is better
- Errorscount
- Sums typed that were wrong or came under 100 ms.
- Lower is better
- Correct, First Thirdcount
- Correct sums among items 1 to 20.
- Higher is better
- Correct, Second Thirdcount
- Correct sums among items 21 to 40.
- Higher is better
- Correct, Last Thirdcount
- Correct sums among items 41 to 60.
- Higher is better
- Last Minus First Thirdcount
- Correct sums in the last third minus the first third.
- Negative means performance fell during the test
- Median Correct RTms
- Median time from a digit's onset to its completed sum, over correct sums.
- Lower is faster
Use and evidence
397 papers from 2021 to 2025 name this task in their title or abstract, down 20% compared with 2016 to 2020. That ranks it 64 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 81 |
| 2024 | 81 |
| 2023 | 83 |
| 2022 | 76 |
| 2021 | 76 |
| 2020 | 83 |
| 2019 | 94 |
| 2018 | 126 |
| 2017 | 79 |
| 2016 | 114 |
| 2015 | 99 |
| 2014 | 104 |
| 2013 | 117 |
| 2012 | 83 |
| 2011 | 60 |
| 2010 | 66 |
| 2009 | 52 |
| 2008 | 50 |
| 2007 | 45 |
| 2006 | 53 |
| 2005 | 40 |
| 2004 | 31 |
| 2003 | 36 |
| 2002 | 22 |
| 2001 | 19 |
| 2000 | 19 |
Use grade B
300 to 999 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
- 45
- Papers on reliability or validity
- 208
- Registered clinical studies using it as an outcome
- 337
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.
- Digits
- 61 digits from 1 to 9, one every 3,000 ms (standard) or 2,000 ms. Each digit stays on screen for 1,000 ms.
- Answers
- 60 sums, each typed with the number keys before the next digit appears. A sum is entered as soon as it is complete, with no Enter key.
- Sequences
- Generated from the session's seed: each digit about equally often, no digit twice in a row, no two sums in a row the same, and 11 two-digit sums in each third.
- Practice
- 10 sums at 4,000 ms per digit, with feedback for 1,000 ms after each, run once more with new digits if fewer than 5 are correct.
This is the visual version: digits are shown on the screen and sums are typed, not spoken. The digit sequences are generated by rule for this task; no published test form is used.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: paced_serial_addition_test from the scored run, one typed sum for each digit after the first. Typed sums have no chance level, so accuracy is not judged against chance. A sum missed before the next digit is part of the score: no sums at all invalidate, and an unbroken run of misses covering half the items withholds the percentile. The same answer on 90% of at least 12 answers invalidates. More than max(2, 20%) sums under 100 ms invalidate; any is flagged. When at least half of 12 or more answers repeat the digit on screen, the session is flagged for review.
Why these rules
There is no correct option to compare with chance, so accuracy is not judged against chance. Missing sums at a fast pace is what the test measures, so misses never invalidate on their own, but an unbroken run of misses covering at least half the items (minimum 8) may mean the participant stopped. No two answers in a row are the same, so one answer on nearly every item cannot follow the digits. A sum typed within 100 ms of a digit's onset cannot include that digit. A sum is always larger than the digit on screen, so answers that repeat the digit mean the instructions were not followed.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Time per digit | 3,000 ms (standard) | 3,000 ms (standard), 2,000 ms |
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 Paced Visual Serial Addition Test in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Gronwall, 1977), with the standard settings (time per digit: 3,000 ms). The main score was total correct (correct sums out of 60).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Gronwall, D. M. A. (1977). Paced auditory serial-addition task: A measure of recovery from concussion. Perceptual and Motor Skills, 44(2), 367-373. https://doi.org/10.2466/pms.1977.44.2.367
- Fos, L. A., Greve, K. W., South, M. B., Mathias, C., & Benefield, H. (2000). Paced Visual Serial Addition Test: An alternative measure of information processing speed. Applied Neuropsychology, 7(3), 140-146. https://doi.org/10.1207/S15324826AN0703_4
- Nagels, G., Geentjens, L., Kos, D., Vleugels, L., D'hooghe, M. B., Van Asch, P., Vuylsteke, K., & De Deyn, P. P. (2005). Paced visual serial addition test in multiple sclerosis. Clinical Neurology and Neurosurgery, 107(3), 218-222. https://doi.org/10.1016/j.clineuro.2004.11.016
- Fisk, J. D., & Archibald, C. J. (2001). Limitations of the Paced Auditory Serial Addition Test as a measure of working memory in patients with multiple sclerosis. Journal of the International Neuropsychological Society, 7(3), 363-372. https://doi.org/10.1017/S1355617701733103
Source papers
- Gronwall DMA (1977). Paced auditory serial-addition task: a measure of recovery from concussion. Perceptual and Motor Skills, 44(2):367-373.Paradigm source, Adults
- Nagels G, Geentjens L, Kos D, Vleugels L, D'hooghe MB, Van Asch P, Vuylsteke K, De Deyn PP (2005). Paced visual serial addition test in multiple sclerosis. Clinical Neurology and Neurosurgery, 107(3):218-222.Paradigm source, Adults
- Fisk JD, Archibald CJ (2001). Limitations of the Paced Auditory Serial Addition Test as a measure of working memory in patients with multiple sclerosis. Journal of the International Neuropsychological Society, 7(3):363-372.Paradigm source, Adults
Questions
How long does the Paced Visual Serial Addition Test take?
About 5 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?
Total Correct, Percent Correct, Dyads, Percent Dyads, Omissions, Errors, Correct, First Third, Correct, Second Third, Correct, Last Third, Last Minus First Third and Median Correct RT. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Paced Visual Serial Addition Test used in research?
397 papers from 2021 to 2025 name it in their title or abstract, down 20% compared with 2016 to 2020. That ranks it 64 of 395 test families in the ConductCognition test census (use grade B). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Paced Visual Serial Addition Test have?
In the published research, 45 papers report its test-retest reliability and 337 registered clinical studies use it as an outcome (evidence grade A in the ConductCognition test census).
Which settings can a researcher change?
Time per digit (3,000 ms (standard), 2,000 ms). 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.
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