Fig 1.

Sample images of (a) complex stimuli (faces and houses) and (b) simple stimuli (closed and open figures); the numbers below each simple stimulus represent the number of white pixels. There are 4 pairs of simple stimuli, and each pair was specially matched in their geometric properties (see text). To comply with PLOS copyright requirements, the original face stimuli were replaced with stand-ins that were preprocessed in an identical fashion and match the visual appearance of the actual stimuli.