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

Monkeys are widely used as model organisms for human vision and cognition. While their anatomy and physiology strongly correspond to humans, it is unclear to what extent their perception matches with ours. Previous studies have evaluated specific aspects of perception, after extensive training on customized tasks that could have altered their perception. To resolve these issues, we trained monkeys to perform an oddball visual search task on natural images, tested them on carefully controlled images to detect a variety of perceptual phenomena, and compared them with humans. This revealed a number of qualitative similarities and differences. Like humans, monkeys showed similar object relations, Webers law and amodal completion. However, unlike humans, monkeys did not show mirror confusion or a global advantage. These findings represent a first comprehensive evaluation of visual perception in monkeys and humans, revealing the limitations of monkeys as a model organism for human vision. SIGNIFICANCE STATEMENTMonkeys are widely used to study for vision and cognition, but is their perception like ours? Most previous studies have tested only single aspects of perception in monkeys, often after extensive training which could have altered their perception. Here, we overcame these limitations by training monkeys on a highly general oddball visual search task, testing them on many perceptual phenomena and comparing them with humans on the same tasks. Our results show that monkeys do indeed see the way we do, but with important differences that highlight their limitations as a model for human vision.