MULTIPLE VISUAL AREAS IN THE POSTERIOR PARIETAL CORTEX OF PRIMATES

This chapter discusses the evidence in macaques in support of a topographic heterogeneity within the posterior parietal cortex involved in visual and visuo-motor functions. This extensive cortical territory appears to contain multiple areas, each characterized by its unique array of connections with other brain regions. The inference could thus be made that the anatomical parcellation of the posterior parietal region has a bearing on its functional and clinical diversity. The parietal territory concerned with vision and eye movements encompasses most of Brodmann's area 7 and is located posteriorly and medially to the somatosensory parietal cortex. The chapter discusses the studies on the complete sets of cortico-cortical connections of three area 7 subdivisions that are associated with visual processing. The results lead to the conclusion that each of them participates in different distributed cortico-cortical networks formed by a constellation of visual, limbic, frontal association and motor areas. Moreover, analysis of the known physiological properties of these areas allowed some inferences about the functional role of each network. Finally, the distinct networks of interconnected cortical areas are correlated to specific subcortical motor targets associated with each area 7 subdivision. © 1993 Academic Press Inc.