Episodic Memory
Source Memory Task
Also called: source monitoring task, source memory test, item and source memory task, context memory task, spatial source memory task
Separate memory for an item from memory for its context: participants say which pictures they saw and on which side of the screen each one appeared.
7-9 minUntimed
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
- 55
- Evidence grade
- C
- Registered clinical studies
- 9
What it measures
Measures memory for where something was seen, apart from memory for the thing itself. Participants study pictures shown on the left or the right of the screen. Each test picture is answered Seen or New, and each Seen answer is followed by the side.
Constructs
- Source memory
- Recollection
- Recognition memory
- Episodic memory
Research uses
- Research on memory for context in aging and mild cognitive impairment
- Studies of recollection in schizophrenia, depression and other conditions
- Experimental research on encoding and retrieval
How the paradigm works
The Source Memory Task measures memory for where something was seen, apart from memory for the thing itself. Remembering the source of a memory, such as the place, the time or the way it was learned, depends on recollecting details of the event, and it can fail while the item itself is still recognized (Johnson, Hashtroudi and Lindsay 1993; Glisky, Polster and Routhieaux 1995). Memory for context declines with age more than memory for content (Spencer and Raz 1995; Old and Naveh-Benjamin 2008), which makes source memory a common measure in research on aging and on conditions that affect recollection.
More about the paradigm
In this version, participants study pictures of everyday objects, animals and plants. Each is shown for 2 seconds in one of two places, on the left or the right of the screen, after a cross between the places, and participants try to remember each picture and the side it appears on, as in the location task of Slotnick, Moo, Segal and Hart (2003). True-or-false arithmetic fills a 60-second delay (0 to 120 in the settings). Each test picture is then shown in the middle of the screen and answered Seen or New with no time limit. After Seen, the participant chooses Left or Right, and the likelier side when unsure, as Cansino and colleagues (2019) asked. The standard list has 24 pictures, 12 on each side, and the test shows them with 24 new ones; a setting gives 16 to 24. A practice of 3 pictures comes first, with a short test of those 3 and 1 new picture and feedback on both answers.
The pictures are the 52 Noto Emoji pictures of the Think and No-Think Task, so the two tests belong in different sessions. Each session gives every picture its role at random: studied on the left, studied on the right, or new.
The main score is source accuracy: the share of studied pictures answered Seen whose side was given correctly (Cansino and colleagues 2019); 0.5 is chance. Recognition of the pictures themselves is reported as d′ with the log-linear correction, with the hit and false alarm rates and corrected recognition. The task also reports a source d′ that does not move with a leaning toward one side, source accuracy for each side, answer times and the delay arithmetic. Source accuracy among recognized pictures still depends partly on how well the pictures were recognized (Murnane and Bayen 1996), so read it with item d′. Scores support research and do not diagnose.
Scores
- Source Accuracy%
- Share of studied pictures answered Seen whose side was given correctly.
- Higher means better memory for where pictures were seen; 0.5 is chance
- Item d-Primed'
- z(hit rate) minus z(false alarm rate) for Seen answers, with the log-linear correction.
- Higher means better recognition of the pictures
- Hit Rate%
- Share of studied pictures answered Seen.
- Higher is better
- False Alarm Rate%
- Share of new pictures answered Seen.
- Lower is better
- Corrected Recognition%
- Hit rate minus false alarm rate.
- Higher is better
- Source d-Primed'
- Among recognized pictures, z of Left answers to pictures studied on the left minus z of Left answers to pictures studied on the right, with the log-linear correction.
- Higher means the sides were told apart better, apart from any leaning to one side
- Source Accuracy, Left%
- Source accuracy for pictures studied on the left.
- Higher is better
- Source Accuracy, Right%
- Source accuracy for pictures studied on the right.
- Higher is better
- Side Answerscount
- Studied pictures answered Seen and given a side; source accuracy rests on these.
- Under 8 is flagged
- Answer Time, Hitsms
- Median time to answer Seen to studied pictures.
- Context for the hit rate
- Answer Time, Correct Rejectionsms
- Median time to answer New to new pictures.
- Context for the false alarm rate
- Side Answer Timems
- Median time to choose Left or Right for recognized studied pictures.
- Informational
- Anticipationscount
- Seen or New answers faster than 100 ms, left out of every score.
- Lower is better
- Pictures Testedcount
- Test pictures shown in the scored run (48 at the standard settings).
- Informational
- Delay Arithmetic Accuracy%
- Share of true-or-false arithmetic problems in the delay answered correctly.
- Context for the delay
- Delayseconds
- Seconds of arithmetic between the study list and the test.
- Informational
Use and evidence
55 papers from 2021 to 2025 name this task in their title or abstract, down 35% compared with 2016 to 2020. That ranks it 245 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 9 |
| 2024 | 12 |
| 2023 | 7 |
| 2022 | 13 |
| 2021 | 14 |
| 2020 | 18 |
| 2019 | 17 |
| 2018 | 19 |
| 2017 | 14 |
| 2016 | 17 |
| 2015 | 14 |
| 2014 | 12 |
| 2013 | 18 |
| 2012 | 12 |
| 2011 | 14 |
| 2010 | 19 |
| 2009 | 6 |
| 2008 | 9 |
| 2007 | 15 |
| 2006 | 10 |
| 2005 | 16 |
| 2004 | 9 |
| 2003 | 7 |
| 2002 | 8 |
| 2001 | 4 |
| 2000 | 6 |
Use grade D
30 to 99 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
- 0
- Papers on reliability or validity
- 5
- Registered clinical studies using it as an outcome
- 9
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.
- Pictures
- 52 emoji pictures of objects, animals and plants from Noto Emoji, the set of the Think and No-Think Task: 48 for the test and 4 for practice.
- Study list
- 24 pictures (standard; 16 to 24), half on the left and half on the right, no more than 3 in a row on one side. Each is shown in its place for 2,000 ms after a 500 ms cross between the two places.
- Delay
- 60 seconds of true-or-false arithmetic (standard; 0 to 120).
- Test
- Every studied picture and as many new ones, 48 in all, each in the middle of the screen and answered Seen or New with no time limit. After Seen, the participant chooses Left or Right, the likelier side when unsure. No more than 4 old or new pictures in a row.
- Practice
- 3 pictures, then a test of those 3 and 1 new picture with 1,500 ms of feedback on both answers.
- Roles
- Each session gives every picture its role at random: studied on the left, studied on the right, or new.
The pictures are those of the Think and No-Think Task, so run the two in different sessions. Source accuracy is read among recognized pictures, so it still depends partly on item memory (Murnane and Bayen, 1996); read it with item d′. 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: source_memory_test from the scored run, one Seen or New answer per picture, each Seen answer with Left or Right, and the delay arithmetic from the same run. Seen or New accuracy significantly below chance (one-sided exact binomial, p < .05, chance 50%) invalidates; accuracy not above chance over 10 or more answers is flagged. The same answer on 90% of the pictures invalidates when accuracy is not above chance. Answers under 200 ms on at least half of 4 or more answered pictures invalidate. Fewer than 8 side answers to recognized pictures, or one side on 90% of at least 12 side answers, is flagged and withholds the percentile. No arithmetic answered in the delay, or delay arithmetic at or below chance over at least 10 answers, is flagged. A hidden tab withholds the percentile.
Why these rules
Half the test pictures were studied and half are new, so guessing gives 50%: Accuracy significantly below chance (one-sided exact test, p < .05) cannot come from guessing; it means the response mapping was reversed or the task was not followed (Slick, Sherman and Iverson 1999 treat below-chance forced-choice performance as definite response bias). Chance-level accuracy can be a real result in impaired participants, so it is only flagged. One option on at least 90% of answered trials, when the correct options are balanced and accuracy is not above chance, means the answers did not depend on the items (the task counterpart of long-string responding in surveys; Curran 2016). An answer under 200 ms is faster than a simple visual reaction, so it cannot reflect the item. Following response-time effort screening for untimed tests (Wise and Kong 2005), the session is invalid only when at least half the answers are that fast. Source accuracy is a share of the recognized pictures, so a session with few of them gives an unstable share, and naming one side for nearly every picture means the sides were not told apart. Skipping the delay arithmetic means that part of the procedure may not have been followed. A hidden tab lets the study, delay or response timers run without the participant, so a percentile is withheld after one.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Pictures studied | 24 | 16 to 24 |
| Arithmetic delay (seconds) | 60 | 0 to 120 |
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
- Untimed test: runs on desktops, laptops, tablets and phones. 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 Source Memory Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Johnson, Hashtroudi & Lindsay, 1993; Slotnick et al., 2003), with the standard settings (pictures studied: 24; arithmetic delay (seconds): 60). The main score was source accuracy (share of studied pictures answered Seen whose side was given correctly).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Johnson, M. K., Hashtroudi, S., & Lindsay, D. S. (1993). Source monitoring. Psychological Bulletin, 114(1), 3-28. https://doi.org/10.1037/0033-2909.114.1.3
- Slotnick, S. D., Moo, L. R., Segal, J. B., & Hart, J., Jr. (2003). Distinct prefrontal cortex activity associated with item memory and source memory for visual shapes. Cognitive Brain Research, 17(1), 75-82. https://doi.org/10.1016/S0926-6410(03)00082-XItems studied on the left or right of the screen, with instructions to remember each item and its place.
- Cansino, S., Torres-Trejo, F., Estrada-Manilla, C., Ramírez-Barajas, L., Pérez-Loyda, M., Nava-Chaparro, A., Hernández-Ladrón-de-Guevara, M., & Ruiz-Velasco, S. (2019). Predictors of source memory success and failure in older adults. Frontiers in Aging Neuroscience, 11, 17. https://doi.org/10.3389/fnagi.2019.00017Source accuracy as the share of recognized pictures given their place, and a guess when the place is not remembered.
- Murnane, K., & Bayen, U. J. (1996). An evaluation of empirical measures of source identification. Memory & Cognition, 24(4), 417-428. https://doi.org/10.3758/BF03200931What the conditional source score does and does not separate.
- Old, S. R., & Naveh-Benjamin, M. (2008). Differential effects of age on item and associative measures of memory: A meta-analysis. Psychology and Aging, 23(1), 104-118. https://doi.org/10.1037/0882-7974.23.1.104Age effects on memory for source and place compared with items.
Source papers
- Johnson MK, Hashtroudi S, Lindsay DS (1993). Source monitoring. Psychological Bulletin, 114(1):3-28.Paradigm source, Adults
- Slotnick SD, Moo LR, Segal JB, Hart J Jr (2003). Distinct prefrontal cortex activity associated with item memory and source memory for visual shapes. Cognitive Brain Research, 17(1):75-82.Paradigm source, Adults
- Cansino S, Torres-Trejo F, Estrada-Manilla C, et al. (2019). Predictors of source memory success and failure in older adults. Frontiers in Aging Neuroscience, 11:17.Paradigm source, Older adults
- Old SR, Naveh-Benjamin M (2008). Differential effects of age on item and associative measures of memory: a meta-analysis. Psychology and Aging, 23(1):104-118.Paradigm source, Young and older adults
- ConductCognition platform normsParadigm source, N/A
Questions
How long does the Source Memory Task take?
About 7 to 9 minutes, as listed in the test library.
What device does a participant need?
Untimed test: runs on desktops, laptops, tablets and phones. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Source Accuracy, Item d-Prime, Hit Rate, False Alarm Rate, Corrected Recognition, Source d-Prime, Source Accuracy, Left, Source Accuracy, Right, Side Answers, Answer Time, Hits, Answer Time, Correct Rejections, Side Answer Time, Anticipations, Pictures Tested, Delay Arithmetic Accuracy and Delay. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Source Memory Task used in research?
55 papers from 2021 to 2025 name it in their title or abstract, down 35% compared with 2016 to 2020. That ranks it 245 of 395 test families in the ConductCognition test census (use grade D). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Source Memory Task have?
In the published research, 0 papers report its test-retest reliability and 9 registered clinical studies use it as an outcome (evidence grade C in the ConductCognition test census).
Which settings can a researcher change?
Pictures studied (16 to 24) and arithmetic delay (seconds) (0 to 120). 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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