English: Location and visuotopic organization of marmoset primary visual cortex (V1). Top: caudal and medial views of the marmoset cerebral cortex, showing the location of V1 (red). The dashed line indicates the region reconstructed in the bottom panels. Middle: The representation of eccentricity from the fovea (“Ecc,” in degrees of visual angle), according to the color scale shown on the right. This reconstruction represents data from a single individual, in which hundreds of recording sites were obtained (Chaplin et al., 2013a). The portion of V1 exposed on the caudal surface of the brain corresponds to the representation of the fovea and parafovea (dark blue), while the far periphery of the visual field is represent at the most anterior portion of the calcarine sulcus (red). Bottom: The representation of polar angle (“Ang”) in the same individual. The lower contralateral visual field (blue, cyan) is found on the dorsal surface, and the upper contralateral field (yellow, orange, red) is found on the ventral surface. The representation of the horizontal meridian (green) divides V1 nearly equally.