Do monkeys see the way we do? Qualitative similarities and differences between monkey and human perception

Monkeys are widely used as models for human vision. While their anatomy and physiology are similar to humans, it is unclear to what extent their perception matches with ours. Previous studies on monkeys have evaluated specific perceptual phenomena after extensive training that could have even altered perception. To resolve these issues, we trained monkeys to perform a highly general oddball visual search task on natural images, and then tested them on carefully controlled image sets to detect a variety of perceptual phenomena and compared their performance with humans. This revealed a number of qualitative similarities and differences. Like humans, monkeys showed similar object relations, Weber’s law and amodal completion. However, unlike humans, monkeys did not show mirror confusion or a global advantage. Our results represent a first comprehensive comparison of visual perception in monkeys and humans, revealing both strengths and limitations of monkeys as a model organism for human visual perception.