RT Journal Article SR Electronic T1 Brain organization, not size alone, as key to high-level vision: Evidence from marmoset monkeys JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.10.19.345561 DO 10.1101/2020.10.19.345561 A1 Alexander J.E. Kell A1 Sophie L. Bokor A1 You-Nah Jeon A1 Tahereh Toosi A1 Elias B. Issa YR 2021 UL http://biorxiv.org/content/early/2021/12/22/2020.10.19.345561.abstract AB Bigger brains are thought to support richer abilities, including perceptual abilities. But bigger brains are typically organized differently (e.g., with more cortical areas). Thus, the extent to which a neural system’s size versus organization underlies complex abilities remains unclear. The marmoset monkey is evolutionarily peculiar: it has a small brain, yet many cortical areas. We used this natural experiment to test organization as source of high-level visual abilities independent of size, via large-scale psychophysics comparing marmosets to different species on identical tasks. Marmosets far out—performed rats—a marmoset-sized rodent—on a simple visual recognition task. On another visual task, which is difficult for both humans and machines, marmosets achieved high performance. Strikingly, their image-by-image behavior revealed that they did so in a manner highly similar to humans—marmosets were nearly as human-like as were macaques. These results suggest a key role for brain organization—not simply size—in the evolution of sophisticated abilities.Competing Interest StatementThe authors have declared no competing interest.