The term occipital gyri refers to a composite structure of the occipital lobe as defined by topology in the human. It consists of the superior occipital gyrus, the middle occipital gyrus and the inferior occipital gyrus ( Mai-1997 ). In the macaque it consists of the occipital gyrus and the inferior occipital gyrus ( Martin-2000 ). Equivalent structures are not found in the smooth cerebral cortex of the rat or mouse