Visual Search Datasets (Jeremy Wolfe)
Repository of three laboratory-collected datasets comprising 80,000 individual trials across three visual search tasks (classic feature search, classic conjunction search, spatial configuration search). Further detail available below.
Previous feature, conjunction, and spatial configuration search tasks have produced valuable information about mean reaction times and slopes. However, with only several hundred trials per subject, spread over several set sizes and divided between target-present and target-absent trials, there is only mediocre information about the distribution of the data. To address this issue, we have collected approximately 4000 trials from each of 9 subjects in a classic feature search task, 10 subjects in a classic conjunction search task, and 9 subjects in a spatial configuration search task.
In the feature search task, subjects looked for a red vertical rectangle among green vertical rectangles. In the conjunction search task, subjects looked for a red vertical rectangle among green vertical and red horizontal rectangles. For the spatial configuration search task, subjects looked for a digital '2' among digital '5's. These stimuli share the same features, but differ in their organization. More specifically, the horizontal components of the 2s and the 5s remained the same, but the positions of the vertical features differ, resulting in a change in the locations of the lines.
The details for the stimuli and method are presented below, and these three datasets are available for downloading by clicking on the appropriate search type at the bottom of the page. We hope that these data can be a test bed for models of visual search. If you use the data, please tell your readers where you got it. We would be grateful to know about any interesting facts that you might dig out of these 80,000 trials.
All three sets of stimuli were created using MATLAB and the Brainard/Pelli Psych Toolbox. A central fixation point in the shape of a white cross appeared in the center of the screen before stimulus onset for all experiments. At the viewing distance of 57.4 cm, a 22.5° square region of a Macintosh computer screen was divided into an invisible 5 x 5 array of cells. Each stimulus was placed at a random location within a cell. For the spatial configuration search, the stimuli were white 2s(target) and 5s (distractor) and each subtended a visual angle of 1.5° x 2.7°. For the conjunction search, targets were red vertical bars among red horizontal and green vertical bars. Each bar subtended 3.5° x 1 ° visual angle. For the feature search, targets were red vertical bars with the same size and luminance profiles as the conjunction search task.