The visual parietal areas in the macaque monkey: Current structural knowledge and ignorance

Classic and current parcellations of the posterior parietal cortex are revi ewed, Whereas earlier studies relied on subjective observation of cortical cytoarchitecture, present parcellations are mostly based on connectional an d physiological criteria. These criteria have led to the identification of five areas in the intraparietal sulcus with alleged visual function: VIP, M IP, PIP, AIP, and LIP. Other visual parietal areas are 7a, in the lateral p arietal surface, and, in the medial parietal wall, 7m, and V6A Present know ledge of the dimensions, boundaries, and connections of the various visual parietal areas is uneven: whereas LIP, 7a, and 7m have been extensively exp lored in anatomical and physiological studies, only scant information is av ailable for most of the intraparietal areas, It is suggested that future st udies address the anatomical and functional parcellation of the posterior p arietal cortex using manifold objective means of study that allow compariso n by independent researchers. (C) 2001 Academic Press.