Grouping and segmentation in human and nonhuman primates

This chapter focuses on the processing of visual information by primates. It presents two main lines of research to illustrate similarities and differences in the processing of visual information by baboons and humans. The first line of research concerns perceptual grouping, a highly adaptive process by which parts of objects are put together into a whole. It demonstrates that baboons are not as quick as humans to group spatially separated elements into a single percept, and reports convergent findings from other species supporting that conclusion. The second line of research concerns the perception of depth cues. It shows that baboons can perceive depth from pictorial depth cues, as humans do, but it also highlights subtle human–baboon differences in their processing of occlusion cues as an indicator of depth, probably as a consequence of species variations in grouping mechanism. The chapter emphasizes the potential heuristic significance of these findings for accounting for species differences in higher cognitive functions.