Dual N-Back Task
Description
Working memory task that requires participants to monitor and respond when stimuli (letters/numbers and/or spatial positions) match those presented n trials back.
Measures: Working memory capacity, executive function, attention, dual-task processing, n-back performance
working memory executive function attention dual-task processing
Ages: 18+ · Populations: adults, research, clinical
About This Test
Participants view a series of stimuli that can include visual letters/numbers, auditory letters/numbers, and/or spatial positions in a 3x3 grid. They press the left key when the letter/number dimension matches n-back, and the right key when the spatial position matches n-back. The task supports single or dual n-back conditions with configurable n values (typically 1-3). Practice trials introduce each dimension separately before combining them. The task uses event-driven response collection allowing responses in any order during dual-task trials.
- Task supports single dimension (letters/numbers OR spatial) or dual n-back (both simultaneously)
- Supports auditory, visual, or combined audio-visual presentation for letter/number dimension
- Practice blocks introduce each dimension separately before dual-task trials
- Event-driven response system allows responses in any order during trials
- Response keys are conditionally registered based on active dimensions
- Visual feedback provided by bolding response labels when keys are pressed
- Default settings based on Jaeggi et al. methodology: 4 dim1 targets, 4 dim2 targets, 2 both targets per block
Test Details
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Scientific Background
Original Task References:
These references describe the original task that this PEBL implementation is based on.
- Jaeggi, S. M., Buschkuehl, M., Perrig, W. J., & Meier, B. (2010). The concurrent validity of the N-back task as a working memory measure. Memory, 18(4), 394-412.
PEBL-Specific References:
These studies used the PEBL version of this task.
- Mueller, S. T. (2012). PEBL Dual N-back Task. Computer software. http://pebl.sourceforge.net
Validation status: Validated · Psychometric data available
This PEBL implementation supports flexible single or dual n-back configurations with auditory, visual, or combined stimulus presentation. Migrated to Layout & Response System v2.3 with event-driven response collection.
Related Tests
Data Output
Creates nback-<SUBNUM>.csv with trial-level data including n-back level, dimensions, stimulus details, response times, and correctness for both response dimensions.
Key Variables
| Variable | Description |
|---|---|
| dim1/dim2 | Dimension types: consonants-a/v/av, numbers-a/v/av, squares, or none |
| nDim | Number of active dimensions: 1 (single n-back) or 2 (dual n-back) |
| n | N-back level (typically 1-3) |
| resp1/resp2 | Semantic response values (LETTER/NUMBER/SQUARES) or <timeout> |
| corr1/corr2 | Correctness for dimension 1 and 2: 1=correct match, 0=correct non-match or incorrect |
| time2/time3 | Reaction times in milliseconds from stimulus onset (first and second responses) |
Example Data
| subnum | block | trial | dim1 | dim2 | nDim | n | isi | d1 | d2 | d3 | d4 | dotext | doaudio | dospatial | timestart | resp1 | corr1 | time2 | rta | resp2 | corr2 | time3 | rtb |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| example | p1 | 1 | consonants-av | none | 1 | 1 | 3000 | 0 | 0 | 8 | 8 | 1 | 1 | 0 | 12298 | <timeout> | 1 | 15048 | 15048 | <timeout> | 1 | 15048 | 15048 |
| example | p1 | 2 | consonants-av | none | 1 | 1 | 3000 | 1 | 0 | 8 | 6 | 1 | 1 | 0 | 15304 | LETTER | 1 | 534 | 534 | <timeout> | 1 | 18054 | 18054 |
| example | p1 | 3 | consonants-av | none | 1 | 1 | 3000 | 0 | 0 | 5 | 5 | 1 | 1 | 0 | 18308 | <timeout> | 1 | 21058 | 21058 | <timeout> | 1 | 21058 | 21058 |
| example | p1 | 4 | consonants-av | none | 1 | 1 | 3000 | 1 | 1 | 5 | 5 | 1 | 1 | 0 | 21312 | LETTER | 1 | 751 | 751 | <timeout> | 0 | 24062 | 24062 |
| example | p1 | 5 | consonants-av | none | 1 | 1 | 3000 | 0 | 1 | 1 | 5 | 1 | 1 | 0 | 24315 | <timeout> | 1 | 27065 | 27065 | <timeout> | 0 | 27065 | 27065 |
| example | p1 | 6 | consonants-av | none | 1 | 1 | 3000 | 0 | 0 | 4 | 3 | 1 | 1 | 0 | 27319 | <timeout> | 1 | 30069 | 30069 | <timeout> | 1 | 30069 | 30069 |
| example | p1 | 7 | consonants-av | none | 1 | 1 | 3000 | 0 | 0 | 6 | 1 | 1 | 1 | 0 | 30323 | <timeout> | 1 | 33073 | 33073 | <timeout> | 1 | 33073 | 33073 |
| example | p1 | 8 | consonants-av | none | 1 | 1 | 3000 | 0 | 0 | 5 | 5 | 1 | 1 | 0 | 33328 | <timeout> | 1 | 36078 | 36078 | <timeout> | 1 | 36078 | 36078 |
| example | p1 | 9 | consonants-av | none | 1 | 1 | 3000 | 0 | 1 | 6 | 5 | 1 | 1 | 0 | 36331 | <timeout> | 1 | 39081 | 39081 | <timeout> | 0 | 39081 | 39081 |
Sample data showing typical output format. Actual values will vary by participant.
About This Test
Working memory task that requires participants to monitor and respond when stimuli (letters/numbers and/or spatial positions) match those presented n trials back.
Category: Memory
Estimated Duration: 10 minutes
Available Translations: 8 languages
Documentation Sources:
Test description file, Test implementation, Parameter schema
Documentation Status: Standard