Working Memory
1-Back Task
Measure continuous working-memory maintenance with a low-load n-back task that fits remote participant workflows.
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
- 3,210
- Evidence grade
- A
- Registered clinical studies
- 790
What it measures
Measures working memory by requiring participants to indicate whether the current stimulus matches the one presented N items ago.
Constructs
- Working memory maintenance
- Continuous performance monitoring
- Memory updating
- Sustained attention
Research uses
- Working memory baseline assessment
- Sustained attention monitoring
- Cognitive load sensitivity profiling
- Neurodevelopmental disorder screening
How the paradigm works
The 1-Back task is a continuous working memory paradigm. Participants view a sequence of letters presented one at a time and must press the spacebar whenever the current letter matches the letter shown one position back. Non-matching letters require no response.
More about the paradigm
The task requires participants to continuously maintain the most recent stimulus in working memory, compare it with the incoming stimulus, make a match/non-match decision, and update their memory with the new stimulus. This maintenance-and-updating cycle engages the phonological loop component of Baddeley's working memory model.
Performance is analyzed using signal detection theory: d-prime separates the participant's ability to discriminate targets from non-targets, independent of their overall tendency to respond. The 1-Back provides a lower-demand baseline against which the 2-Back can be compared to isolate the cost of increased working memory load.
Scores
- Overall Accuracy%
- Proportion of all trials (targets + non-targets) correctly classified.
- Higher is better
- Hitscount
- Number of targets correctly identified (pressed spacebar on match).
- Higher is better
- Missescount
- Number of targets missed (failed to press on match).
- Lower is better
- False Alarmscount
- Responses to non-target stimuli (pressed spacebar on non-match).
- Lower is better
- Correct Rejectionscount
- Non-target stimuli correctly ignored.
- Higher is better
- d-Primed'
- Signal detection sensitivity: Z(hit rate) - Z(false alarm rate). Primary measure of working memory discriminability.
- Higher is better
- Hit RTms
- Average reaction time on correct target detections.
- Lower is better
Use and evidence
3,210 papers from 2021 to 2025 name this task in their title or abstract, up 22% compared with 2016 to 2020. That ranks it 6 of 582 test families in our census. The counts cover every version of the task, so the 2-Back Task page shows the same figures. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 832 |
| 2024 | 628 |
| 2023 | 567 |
| 2022 | 586 |
| 2021 | 597 |
| 2020 | 595 |
| 2019 | 530 |
| 2018 | 547 |
| 2017 | 487 |
| 2016 | 472 |
| 2015 | 419 |
| 2014 | 423 |
| 2013 | 393 |
| 2012 | 333 |
| 2011 | 290 |
| 2010 | 256 |
| 2009 | 184 |
| 2008 | 200 |
| 2007 | 152 |
| 2006 | 125 |
| 2005 | 113 |
| 2004 | 108 |
| 2003 | 93 |
| 2002 | 66 |
| 2001 | 71 |
| 2000 | 76 |
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
- 104
- Papers on reliability or validity
- 649
- Registered clinical studies using it as an outcome
- 790
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 this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.39.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: nback_test, press on matches (about 32%) within 1.5 s. No responses at all invalidates. Responding mainly on non-matches invalidates; not separating matches is flagged. Missed matches are the measure: only a run of misses covering half the matches (minimum 8) is flagged and withholds the percentile.
Why these rules
The hit rate is half of d-prime, the primary measure. 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. Missed targets are what this test measures, so missed responses never invalidate on their own. A session with no responses is invalid. An unbroken run of misses covering at least half the response trials (minimum 8) may mean the participant stopped, so the session is flagged and its percentile withheld. Responses under 100 ms follow the timed-test rule.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Number of trials | 48 | 30 to 80 |
| Target percentage | 0.33 | 0.2 to 0.5 |
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.
Included in these batteries
Each battery runs this test with others in a fixed order, with standard settings.
- Working Memory and Learning Battery4 tests, 19 minutes per participant
- Language-Minimized Screening Battery8 tests, 30 minutes per participant
- School-Age Battery5 tests, 33 minutes per participant
Cite and describe
Participants completed the 1-Back Task in a web browser (ConductCognition task version 1.0.1, scoring version 1.0.0; Kirchner, 1958), with the standard settings (number of trials: 48; target percentage: 0.33). The main score was d-prime (signal detection sensitivity: Z(hit rate) - Z(false alarm rate)).
Paradigm source: Kirchner (1958).
ConductCognition versions: task version 1.0.1, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
Source papers
- Bopp KL, Verhaeghen P (2020). Aging and n-back performance: A meta-analysis. Journals of Gerontology: Psychological Sciences, 75(2):229-240.Paradigm source, 18-79
Questions
How long does the 1-Back Task 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?
Overall Accuracy, Hits, Misses, False Alarms, Correct Rejections, d-Prime and Hit RT. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the 1-Back Task used in research?
3,210 papers from 2021 to 2025 name it in their title or abstract, up 22% compared with 2016 to 2020. That ranks it 6 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 1-Back Task have?
In the published research, 104 papers report its test-retest reliability and 790 registered clinical studies use it as an outcome (evidence grade A in the ConductCognition test census).
Which settings can a researcher change?
Number of trials (30 to 80) and target percentage (0.2 to 0.5). 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.
Run this test in your next study
Start free with 10 free participants on any test, then use participant credits or a yearly plan.
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