Fig. 1

Examples of the presented visual images. The images consisted of (A) four rectangles and (B) four ovals. The rectangles formed an abstract image, while the four ovals formed as a face. The subjects were instructed to determine whether the target image (first as Non-Face condition gazing rectangles of abstract image; second as Face condition gazing ovals forming face) were the same as those in the previously presented image in terms of its size and arrangement. When the subjects paid attention to the rectangles, only an abstract image was perceived. Next, after being instructed that the four ovals formed a face by ignoring rectangles, the subjects gradually recognized the arrangement of the four ovals as a face. The two blocks were administered successively using the same figure sets in the same sequence, only subjective perception differing.