2023 Volume 40 Issue 1 Pages 46-53
Visual local motion is detected from spatiotemporal correlations of luminance and other visual feature within a small receptive field, but the detected motion is onedimensional: it cannot uniquely determine two-dimensional motion direction and speed. Although pri-mates solve this problem by integrating local motion components, few studies have examined the process of motion integration in other lineages, and no phylogenetic and ecological discussions have been made through species comparisons. This paper presents my studies showing from behavioral experiments that pigeons (Columba livia) differ from primates in their visual motion integration. I review the studies investigating motion integration in other species and discuss the factors that would cause the species difference of motion integration. I propose the hypothesis that the species difference of motion integration is related to the ability to track prey and other moving objects precisely and that the degree of orientation selectivity in early visual areas and the degree of development of two visual pathways from the retina underlie the species difference.
