Figure 1.

Examples of our stimuli. (a) Patterns in the green box were erroneously signalled as faces by a computational face detection system (developed by Pittsburgh Pattern Recognition Systems). Based on human observers' perceptual ratings, these false-alarms were divided into low face-like and high face-like patterns. (b) Sample stimuli that show the range of face-semblance used in the present study. Rows from top to bottom show images with increasing level of similarity, from no face-semblance to genuine faces, as rated by human observers.