We use cookies to ensure that we give you the best experience on our website. You can change your cookie settings at any time. Otherwise, we'll assume you're OK to continue.

Durham University

Department of Anthropology


Publication details for Professor Robert A. Barton

Barton, R.A. (2004). Binocularity and brain evolution in primates. Proceeedings of the National Academy of Sciences of the United States of America 101(27): 10113-10115.

Author(s) from Durham


Primates are distinguished by frontally directed, highly convergent orbits, which are associated with stereoscopic vision. Although stereoscopic vision requires specialized neural mechanisms, its implications for brain evolution are unknown. Using phylogenetic comparative analysis, I show that evolutionary increases among primate taxa in the degree of orbital convergence correlate with expansion of visual brain structures and, as a consequence, with the overall size of the brain. This pattern is found across the whole primate order and is also repeated within each of the two major primate subtaxa. The visual expansion associated with increased binocularity is specific to the parvocellular visual pathway, consistent with recent evidence implicating this pathway in fine-grained stereopsis. The results support the hypothesis that brain size evolution in primates was associated with visual specialization.