Cortical magnification in human visual cortex parallels task performance around the visual field

Human vision has striking radial asymmetries, with performance on many tasks varying sharply stimulus polar angle. Performance is generally better the horizontal than vertical meridian, and lower upper these asymmetries decrease gradually deviation from meridian. Here, we report cortical magnification at a fine angular resolution around visual field. This precision enables comparisons between behavior, retinal cell densities, in twin pairs. We show that human primary cortex, measured 163 subjects, varies substantially field, pattern similar to behavior. These cortex are larger those found retina, they correlated monozygotic findings indicate tight link topography suggest field partly heritable.