Chapter 2 The evolution of parietal cortex in primates

Publication date: 2018 Source:Handbook of Clinical Neurology, Volume 151 Author(s): Jon H. Kaas, Hui-Xin Qi, Iwona Stepniewska Many of the adaptive changes in the functional organization of parietal cortex of humans emerged in past in the early primates as they depended on visually guided forelimb use to grasp branches and food. Currently, human, apes and some monkeys have four well-defined subdivisions of anterior parietal cortex, areas 3a, 3b, 1 and 2 of Brodmann. In some of the smaller monkeys, and in stepsirrine primates (galagos, lemurs, and lorises), especially areas 1 and 2 are less developed, and the existence of an area 2 is questionable. In galagos, area 3b, the homologue of S1 in other mammals, has a more primitive somatotopy, is less devoted to representing the hand, and information from facial whiskers is more important. Humans and other primates also have more somatosensory areas in lateral parietal cortex than most mammals. While the regions of the second somatosensory area, S2 is divided into S2 and the parietal ventral area, PV in most mammals, primates have the additional caudal ad rostral ventral somatosensory areas, VSc and VSr. Posterior parietal cortex is another region of posterior cortex that has changed greatly from non-primate ancestors in having a more caudal half that is heavily devoted to further processing visual information for guiding different actions, such as running, reaching, looking, and grasping. All primates have at least 8 small su...

Source: Handbook of Clinical Neurology - March 7, 2018 Category: Neurology Source Type: research