Visual Search Task
A two-phase visual search paradigm where participants locate target characters among distractors in arrays of varying sizes, with targets defined by character identity and/or color.
Participants view the target character, then search for it in an array of letters. When they locate the target or determine it's absent, they click the mouse. The letters are then replaced by circles, and participants click on the circle at the target's location or click 'NONE' if absent. The task manipulates search set size (10/20/30 items), number of targets present (0/1/5), target characters (O/X), and target colors (white/green).
Measures: Visual attention, visual search efficiency, target detection accuracy, spatial memory for target locations, and the effects of set size and target presence on search performance.
- Migrated to PEBL 2.3 with Layout integration (layout-only mode) on January 16, 2026
- Part of the PEBL Cognitive Decathlon - a standardized battery of 10 cognitive tasks
- Uses two-phase mouse response: (1) click when search complete, (2) click on target location or NONE
- Includes 8 language translations: English, Swedish, German, Spanish, French, Italian, Dutch, Portuguese
- Layout integration provides header/footer zones but does not use standard response system (incompatible with spatial click responses)
- Practice trials (10 trials: 5 target-absent, 5 target-present) precede experimental trials
- Break offered every 40 trials
- Default configuration: 5 repetitions × 2 targets (O/X) × 2 colors (white/green) × 3 set sizes (10/20/30) × 3 presence conditions (0/1/5) = 180 trials
| boxwidth | Width in pixels of search box (default: 600) |
| boxheight | height in pixels of search box (default: 400) |
| targs | Text string of target symbols (default: OX) |
| foils | Text string of foil symbols (default: UDGCQ) |
| searchsizes | Search array sizes (list of integers) (default: Array) |
| numtargs | Number of targets conditions (list of integers) (default: Array) |
| targcols | Target colors (list of color names) (default: Array) |
| foilcolor | Foil color (default: white) |
| reps | Number of repetitions for whole design. (default: 5) |
| Validation | not-validated |
| Psychometric data | Not available |
| Normative data | Not available |
| sub | trial | time | numtargs | size | targchar | targcol | stim | resp | corr | rt1 | rt2 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| example | 1 | 58778 | 0 | 20 | O | white | GCUDQCDUQGDGCQUQCUGD | 0 | 1 | 2268 | 945 |
| example | 2 | 62813 | 5 | 10 | X | green | XXXXXDQUGC | 1 | 1 | 718 | 870 |
| example | 3 | 65209 | 1 | 10 | O | green | OQGDUCUDCG | 1 | 1 | 690 | 1019 |
| example | 4 | 67727 | 1 | 20 | X | white | XUDGQCUCDQGDUCQGDQCU | 1 | 1 | 633 | 666 |
| example | 5 | 69851 | 5 | 10 | O | white | OOOOOQGCDU | 3 | 1 | 1118 | 1039 |