Fig. 1

Experiment 1: Visual search for camouflaged target. a Target objects. When a target was present, it was either a human head (left) or a digital embryo (right), each shown here at 4 × their size in actual camouflage images. The human head target can be seen at the top right corner of the camouflage image in panel B. b–e Task paradigm. Subjects viewed the camouflaged scene (panel B), followed by a 0.5 s random dot stimulus mask (RDS mask; panel C). Subjects reported whether or not the preceding stimulus contained a target using designated onscreen buttons (panel D). Subjects were next presented with a blank outline of the image and were required to report the perceived location of the target (if the target was present) or the center of the image (if the target was absent) using a mouse click. An ‘X’ appeared at the clicked location (panel E). Not drawn to exact scale. See text for details