Fig. 1.

Schematic description of the three tasks. a Experiment 1 (Object arrays). b Experiment 2 (Natural images). c Experiment 3 (Waldo images). All tasks started with a 500 ms fixation period. Experiments 1 and 2 were followed by presentation of the target object for 1500 ms. In Experiment 1, the target object appeared at a random 2D rotation and the category descriptor was also shown to emphasize that subjects had to invariantly search for a different exemplar of the corresponding category shown at a different rotation. In Experiment 2, the target object was also different from the rendering in the search image. The target object (Waldo) was not shown in every trial in Experiment 3. In Experiments 1 and 2, there was an additional 500 ms delay after the target object presentation. Finally, the search image was presented and subjects had to move their eyes until they found the target. In Experiments 2 and 3, subjects also had to use the computer mouse to click on the target location. Due to copyright, in this and subsequent figures, all the search images were distorted by blurring. Due to copyright, we replaced the picture of a cat in a used in the experiment with a similar picture of a cat. Due to copyright, in b, during target presentation we replaced the picture used in the actual experiment with the text “Minnie Mouse”. As noted under “Data availability”, we made all the data including original images publicly available for research use