Fat Face Illusion, or Jastrow Illusion with Faces, in Humans but not in Chimpanzees

When two identical faces are aligned vertically, humans readily perceive the face at the bottom to be fatter than the top one. This phenomenon is called the fat face illusion . Furthermore, an apparent similarity has been pointed out between the fat face illusion and the Jastrow illusion. Recent stu...

Full description

Bibliographic Details
Main Author: Masaki Tomonaga
Format: Article
Language:English
Published: SAGE Publishing 2015-12-01
Series:i-Perception
Online Access:https://doi.org/10.1177/2041669515622090
Description
Summary:When two identical faces are aligned vertically, humans readily perceive the face at the bottom to be fatter than the top one. This phenomenon is called the fat face illusion . Furthermore, an apparent similarity has been pointed out between the fat face illusion and the Jastrow illusion. Recent studies have suggested the importance of facial contours and the role of basic-level processing of faces. In the present study, we directly compared the typical Jastrow illusion and fat face illusion in humans and chimpanzees using the same task. Both humans and chimpanzees clearly showed the Jastrow illusion, but only humans perceived the face at the bottom as fatter than the top. Although further examination is necessary, these results might reflect different processing levels of faces between the two species.
ISSN:2041-6695