parieto-occipital sulcus parieto-occipital sulcus in neuroanatomy, the parieto-occipital sulcus (also called the parieto-occipital fissure) is a deep sulcus in the cerebral cortex that marks the boundary between the cuneus and precuneus, and also between the parietal and occipital lobes. only a small part can be seen on the lateral surface of the hemisphere, its chief part being on the medial surface. parieto-occipital sulcusfig. 726: lateral surface of left cerebral hemisphere, viewed from the side.fig. 727: medial surface of left cerebral hemisphere.detailsidentifierslatinsulcus parietooccipitalis, fissura parietooccipitalisneuronames52neurolex idbirnlex_1428ta98a14.1.09.108ta25437fma83754anatomical terms of neuroanatomy the lateral part of the parieto-occipital sulcus (fig. 726) is situated about 5 cm in front of the occipital pole of the hemisphere, and measures about 1.25 cm. in length. the medial part of the parieto-occipital sulcus (fig. 727) runs downward and forward as a deep cleft on the medial surface of the hemisphere, and joins the calcarine fissure below and behind the posterior end of the corpus callosum. in most cases, it contains a submerged gyrus. function the parieto-occipital lobe has been found in various neuroimaging studies, including pet (positron-emission-tomography) studies, and spect (single-photon emission computed tomography) studies, to be involved along with the dorsolateral prefrontal cortex during planning. gallery animation of left cerebral hemisphere. parieto-occipital sulcus shown in red. medial surface of right hemisphere. parieto-occipital sulcus labeled at top right as "*" medial surface of left hemisphere. parieto-occipital sulcus visible at top left.