Symmetry Span Task
Description
Visuospatial working memory span task requiring participants to remember spatial locations while making symmetry judgments.
About This Test
Participants judge whether 8x8 grid patterns are vertically symmetrical (True/False), then see a red square flash in one cell of a 4x4 grid to remember. After a series of symmetry-square pairs (set size 2-5), they recall the square locations in order by clicking on the grid. The task includes practice blocks for spatial recall only, symmetry judgments only, and combined trials. Symmetry performance is monitored and participants must maintain 85% accuracy on symmetry judgments to ensure divided attention. If threshold is not met, participants may repeat practice with feedback. The main test consists of sets of 3 trials at each set size (2, 3, 4, 5) in random order.
Test Details
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Scientific Background
Original Task References:
These references describe the original task that this PEBL implementation is based on.
- Kane, M. J., Hambrick, D. Z., Tuholski, S. W., Wilhelm, O., Payne, T. W., & Engle, R. W. (2004). The generality of working memory capacity: A latent-variable approach to verbal and visuospatial memory span and reasoning. Journal of Experimental Psychology: General, 133(2), 189-217.
PEBL-Specific References:
These studies used the PEBL version of this task.
- Mueller, S. T. (2012). PEBL Symmetry Span Task. Computer software. http://pebl.sourceforge.net
Data Output
Creates three files: (1) symspan-<SUBNUM>.csv with trial-level recall data, (2) symspan-sym-<SUBNUM>.csv with individual symmetry judgment responses and reaction times, and (3) symmetryspan-report-<SUBNUM>.html with summary statistics and visualizations.
Example Data
example-data.csv Primary
Trial-level spatial recall data with columns: subnum, trial, probtime, memtime, length, numstim, stim, resp, memcorr, time, distcorr, numcorrdist, totnumdist, runningcorrect, runningtotal
| subnum | trial | probtime | memtime | length | numstim | stim | resp | memcorr | time | distcorr | numcorrdist | totnumdist | runningcorrect | runningtotal |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| aaa | 1 | -1 | 1000 | 2 | 3 | 2|9 | 2|9 | 1 | -1 | -1 | 0 | 0 | 0 | 0 |
| aaa | 1 | -1 | 1000 | 3 | 6 | 3|12|7 | 3|12|7 | 1 | -1 | -1 | 0 | 0 | 0 | 0 |
| aaa | 1 | -1 | 0 | 0 | 1 | NA | 2585 | 1 | 1 | 1 | 1 | 1 | ||
| aaa | 1 | -1 | 0 | 0 | 1 | NA | 2329 | 1 | 2 | 2 | 3 | 3 | ||
| aaa | 1 | -1 | 0 | 0 | 1 | NA | 1684 | 1 | 1 | 1 | 4 | 4 | ||
| aaa | 1 | -1 | 0 | 0 | 1 | NA | 2292.5 | 1 | 2 | 2 | 6 | 6 | ||
| aaa | 1 | -1 | 0 | 0 | 1 | NA | 1562 | 1 | 1 | 1 | 7 | 7 | ||
| aaa | 1 | 3852 | 650 | 2 | 4 | 10|7 | 10|7 | 1 | 1681.5 | 1 | 2 | 2 | 9 | 9 |
| aaa | 2 | 3852 | 650 | 2 | 4 | 2|14 | 2|14 | 1 | 1489 | 1 | 2 | 2 | 11 | 11 |
example-data-sym.csv
Symmetry judgment data with columns: subnum, trial, symprestime, memtime, length, numcorrdist, totnumdist, image, corrans, resp (1=correct, 0=incorrect, -1=timeout), rt (reaction time in ms)
| subnum | trial | mathprestime | memtime | length | numcorrdist | totnumdist | type | corr | rt | |
|---|---|---|---|---|---|---|---|---|---|---|
| aaa | 1 | -1 | 0 | 0 | 1 | 1 | D | 1 | 2585 | |
| aaa | 1 | -1 | 0 | 0 | 1 | 1 | D | 1 | 1254 | |
| aaa | 1 | -1 | 0 | 0 | 2 | 2 | D | 1 | 3404 | |
| aaa | 1 | -1 | 0 | 0 | 1 | 1 | D | 1 | 1684 | |
| aaa | 1 | -1 | 0 | 0 | 1 | 1 | D | 1 | 2472 | |
| aaa | 1 | -1 | 0 | 0 | 2 | 2 | D | 1 | 2113 | |
| aaa | 1 | -1 | 0 | 0 | 1 | 1 | D | 1 | 1562 | |
| aaa | 1 | 3852 | 650 | 2 | 1 | 1 | D | 1 | 2010 | |
| aaa | 1 | 3852 | 650 | 2 | 2 | 2 | D | 1 | 1353 |
example-data-report.html Report
HTML report with summary statistics (total correct, partial credit, accuracy by set size), performance graphs, and trial-by-trial breakdown
📊 Interactive HTML Report Preview Open in new window →
Sample data showing typical output format. Actual values will vary by participant.
About This Test
Visuospatial working memory span task requiring participants to remember spatial locations while making symmetry judgments.
Category: Memory
Estimated Duration: 15 minutes
Available Translations: 7 languages
Documentation Sources:
Test description file, Test implementation, Parameter schema
Documentation Status: Standard