Processing Speed
Symbol Key Game
Also called: symbol matching game, symbol and number matching game, coding speed game
Measure how many symbols older adults match to their numbers in 90 seconds: a key of nine symbol and number pairs stays on the screen, and one symbol at a time appears to match.
3-4 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
- 2,557
- Evidence grade
- A
- Registered clinical studies
- 1,457
Figures for the Symbol Coding test, the published test this game is compared with.
How these are countedWhat it measures
A timed matching game for research on processing speed in older adults. A key of nine symbols, each with its number, stays at the top of the screen. One symbol at a time appears in the middle, and the player taps or clicks its number, or presses the number key. The score counts the symbols matched in 90 seconds. It is a raw research measure with no percentile.
Constructs
- Processing speed
- Visual-motor mapping
- Sustained task efficiency
Research uses
- Research on processing speed in older adults
How the paradigm works
The Symbol Key Game is a timed matching game for research on processing speed in older adults. A key of nine symbols, each over its number, stays at the top of the screen. One symbol at a time appears in the middle, and the player taps or clicks its number among nine buttons at the foot of the screen, or presses the number key on a keyboard. The next symbol appears at once, and the game stops after 90 seconds. The design follows the coding test, in which people match symbols to numbers with a key of nine pairs for 90 seconds and the first items are guided (Benedict and colleagues 2017); a self-administered tablet version has been described (Rao and colleagues 2017). Jaeger (2018, Journal of Clinical Psychopharmacology) reviews the coding test's wide use in research. The symbols, the order of the 150 items, the layout and the words here are our own, and no symbol comes from a published test.
More about the paradigm
The paper counts and grades on this page are those of the Symbol Coding test, the published test the game is compared with, not the game's own. A practice of 10 symbols comes first: the right number lights up after each answer, and the practice runs once more when fewer than 7 of the 10 are right. The 90 seconds are six 15-second segments, and the game shows no countdown. Each session takes one of 12 alternate forms, each a new pairing of the same nine symbols with the numbers. The order of the forms is drawn once for each participant, and each session takes the next form, so a reload keeps its form, a missed visit skips none, and no form comes back until all 12 are used. A form's scores are pooled with the others' only after first sessions show the forms are equally hard.
Scores
- Symbols Matchedcount
- Right answers in the clean 15-second segments, times 6, divided by the number of clean segments. Empty when fewer than 5 segments are clean.
- Higher means more symbols matched in 90 seconds; compared within a study
- Wrong Answerscount
- Answers on a number that did not match the symbol, in the clean segments.
- Secondary: context for the main score
- Median Answer Timems
- Median time from a symbol's appearance to a right answer, in the clean segments.
- Informational
- Share of Key Answers%
- Share of the answers in the clean segments given with a number key, not a tap or a click.
- Informational: keys are faster than a mouse, so keep one input for each participant
- Clean Segmentscount
- The 15-second segments in which a symbol was shown and no tab was hidden and the window did not change size or turn. At least 5 of the 6 are needed to score.
- Quality check
Use and evidence
2,557 papers from 2021 to 2025 name this task in their title or abstract, up 48% compared with 2016 to 2020. That ranks it 9 of 582 test families in our census. These counts belong to the Symbol Coding test, the published test this game is compared with. This game is a new measure, so its own reliability and norms come from use. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 626 |
| 2024 | 589 |
| 2023 | 499 |
| 2022 | 428 |
| 2021 | 415 |
| 2020 | 439 |
| 2019 | 362 |
| 2018 | 342 |
| 2017 | 307 |
| 2016 | 280 |
| 2015 | 255 |
| 2014 | 272 |
| 2013 | 209 |
| 2012 | 175 |
| 2011 | 150 |
| 2010 | 148 |
| 2009 | 133 |
| 2008 | 123 |
| 2007 | 100 |
| 2006 | 115 |
| 2005 | 82 |
| 2004 | 69 |
| 2003 | 74 |
| 2002 | 58 |
| 2001 | 50 |
| 2000 | 62 |
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
- 135
- Papers on reliability or validity
- 860
- Registered clinical studies using it as an outcome
- 1,457
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 the Symbol Coding test, the published test this game is compared with, not the game's own.
Source: ConductCognition test census 0.39.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Symbols
- Nine symbols drawn in code, each a stack of three separate marks, so none is a letter or a digit and none comes from a published coding test. Any two symbols share at most one mark. The game look adds a soft background and a soft shadow under the key and the keypad; the plain look shows them on white. Both looks draw every symbol the same way.
- Key and keypad
- A key of 9 symbols, each over its number, stays at the top of the screen. The nine number buttons are at the foot, in one row on a wide screen and three by three on a tall one. Each button is at least 64 px, the symbol in the middle at least 96 px and each key symbol at least 48 px. The layout is worked out from the window before each symbol, and it is the same in older-adult mode.
- Forms
- 12 alternate forms, each a new pairing of the same 9 symbols with the numbers, over one fixed order of 150 symbols. Each participant gets the forms in an order drawn once for them, and each session takes the next form after the sessions they began before it.
- Test
- 90 seconds from the first symbol, in six 15-second segments, with no countdown shown. One symbol at a time appears in the middle, and the next appears at once after an answer. The first tap, click or number key that counts answers. At 90 seconds the game stops, and the symbol on the screen is recorded with no answer.
- Answers
- A press sooner than 100 ms after a symbol appears answers nothing. Nor does a press of the same number within 300 ms of an answer (a double click or a double tap), a held key, a second finger or a palm. Each of these is counted.
- Practice
- 10 symbols, with the right number lighting up after each answer. The practice runs once more when fewer than 7 of the 10 are right.
- Scores
- The symbols matched in the clean segments, scaled to six segments (the main score), the wrong answers, the median answer time, the share of answers given with a number key and the number of clean segments. A segment is left out when the tab was hidden or the window changed size or turned during it, and the score needs at least 5 of the 6.
- Devices
- Desktops and laptops at release. Tablets open once two filmed tablets pass the device timing check, and phones do not run the game. Keys are faster than a mouse, so keep each participant on one device and one input at every visit.
The design follows the coding test of Benedict and colleagues (2017); the symbols, the order of the items, the layout, the words and the looks are our own. This is a new measure for research with older adults: its reliability and norms come from use, the figures published in those studies are not its own, and it computes no percentiles. A practice visit before the baseline is advised, and for a retest 7 to 28 days later, add a second visit to the same study.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: symbol_key_game test symbols in the clean 15-second segments (a segment with a hidden tab or a resized window is left out, and so is one no row reaches; a symbol left up for a whole segment counts as played), one answer among nine numbers. Fewer than 5 clean segments, no answers, or fewer than half of the answers matching the symbol invalidates. One number on 60% or more of the answers is flagged. Responses under 100 ms follow the timed-test rule.
Why these rules
A symbol has one right number among nine, so guessing gives about 11%; fewer than half right is far above that and means the key was not used, which is a ConductScience choice, not a published limit. Missed responses and responses under 100 ms keep the platform's timed-test rule: more than max(3, 25%) missed responses or more than max(2, 20%) responses under 100 ms invalidate, and any is flagged. A response under 100 ms cannot be a reaction to the stimulus. A segment in which the tab was hidden or the window changed size or turned was not played as the others were, so it is left out, and the score needs 5 of the 6. The open symbol at the end of the 90 seconds is not an omission, because the game stops while it is on screen. One number on most answers means the answers did not depend on the symbols.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Look | Game | Game, Plain |
Every plan can change the look, which never changes how a result is scored.
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.
- 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 Symbol Key Game in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Jaeger, 2018), with the standard settings (look: Game). The main score was symbols matched (right answers in the clean 15-second segments, times 6, divided by the number of clean segments).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Benedict, R. H. B., DeLuca, J., Phillips, G., LaRocca, N., Hudson, L. D., & Rudick, R. (2017). Validity of the Symbol Digit Modalities Test as a cognition performance outcome measure for multiple sclerosis. Multiple Sclerosis Journal, 23(5), 721-733. https://doi.org/10.1177/1352458517690821The format of a coding test: a key of nine symbol and number pairs, 90 seconds and guided first items (methods read in full). The game takes the format, not the symbols.
- Benedict, R. H. B., Smerbeck, A., Parikh, R., Rodgers, J., Cadavid, D., & Erlanger, D. (2012). Reliability and equivalence of alternate forms for the Symbol Digit Modalities Test: implications for multiple sclerosis clinical trials. Multiple Sclerosis Journal, 18(9), 1320-1325. https://doi.org/10.1177/1352458511435717Alternate forms that keep the key's structure, which the game's 12 forms do with one fixed order of items (abstract read).
- Rao, S. M., Losinski, G., Mourany, L., Schindler, D., Mamone, B., Reece, C., et al. (2017). Processing speed test: Validation of a self-administered, iPad-based tool for screening cognitive dysfunction in a clinic setting. Multiple Sclerosis Journal, 23(14), 1929-1937. https://doi.org/10.1177/1352458516688955A self-administered tablet version of the coding task, cited for the format only (abstract read).
- Jaeger, J. (2018). Digit Symbol Substitution Test: The case for sensitivity over specificity in neuropsychological testing. Journal of Clinical Psychopharmacology, 38(5), 513-519. https://doi.org/10.1097/JCP.0000000000000941A review of the coding test's use in research across many groups and treatments (abstract read).
Source papers
Questions
How long does the Symbol Key Game take?
About 3 to 4 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?
Symbols Matched, Wrong Answers, Median Answer Time, Share of Key Answers and Clean Segments. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Symbol Coding test used in research?
These counts belong to the Symbol Coding test, the published test this game is compared with. This game is a new measure, so its own reliability and norms come from use. 2,557 papers from 2021 to 2025 name the task in their title or abstract, up 48% compared with 2016 to 2020. That ranks it 9 of 582 test families in the ConductCognition test census (use grade A). Source: ConductCognition test census 0.39.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Symbol Coding test have?
These counts belong to the Symbol Coding test, the published test this game is compared with. This game is a new measure, so its own reliability and norms come from use. In the published research, 135 papers report the task's test-retest reliability and 1,457 registered clinical studies use it as an outcome (evidence grade A in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
Look (Game, Plain). Every plan can change the look, which never changes how a result is scored.
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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