The eye-size illusion: Psychophysical characteristics, generality, relation to holistic processing, and a role for visual experience

Abstract

Rakover (2011) observed a novel eye-size illusion: when increasing the size of a face but keeping the size of its eyes unchanged, the eyes are perceived to be larger than in the original face. Here, we systematically manipulated the face size and found that the magnitude of this illusion linearly changed as a function of the face frame size (Experiment 1). Additionally, the same magnitude of an illusion was observed for the perception of the size of the mouth when we changed the face frame but kept the mouth size constant (Experiment 2). Further, we investigated whether the magnitude of the illusion was affected by stimulus inversion and differential experience with particular categories of faces. We found that when the faces and eyes were presented upside down, the magnitude of the illusion was significantly reduced in both Chinese participants and Caucasian participants (Experiment 3). We also found that the illusion was more salient with own-race and own-age faces versus other-race and other-age faces (Experiment 4). The illusion reflects holistic processing because the perception of eye or mouth size occurs in the relational context of the whole face; when the face is seen upside down, thereby disrupting holistic processing, the magnitude of the illusion is reduced. The presence of other-race and other-age effects additionally suggests that experience plays a role in producing the illusion.

Meeting abstract presented at VSS 2014