Review of Studies on Visual Perception in Grey Parrots (Psittacus erithacus): The Muller-Lyer Illusion, Amodal and Modal Completion

• Published in: Animal Behavior and Cognition
• Main Author: Irene M. Pepperberg
• Format: Article in Journal/Newspaper
• Language: English
• Published: Animal Behavior and Cognition 2017
• Subjects: Grey parrots; Optical illusions; Parrot visual perception; Müller-Lyer; Kanisza; Amodal completion; Zoology; QL1-991; Avian Studies
• Online Access: https://doi.org/10.26451/abc.04.03.14.2017; https://doaj.org/article/76481b98fabc4d98afc04f5a5265e656

Few avian studies on optical illusions are directly comparable to those with humans. Grey parrots that have some referential use of English speech, however, allow for such comparative studies, as these birds can be tested just as are humans, by asking them to describe exactly what they have seen. Here I review two studies, one on the Müller-Lyer illusion (Pepperberg, Vicinay, & Cavanagh, 2008), one on amodal and modal perception (Pepperberg & Nakayama, 2016), that demonstrate similarities between human and Grey parrot perceptual abilities.