Reaching and Grasping

Although sensory information is used to perceive the world, ultimately perceptions must result in [Page 855]actions to have an effect. Traditionally, more research and popular interest have been devoted to sensory perception than sensorimotor actions, but that has been changing with growing awareness of the sophistication of such actions and the underlying neural mechanisms. In addition, awareness has grown regarding how body parts and potential actions influence perception. The importance of sensory information for planning and controlling actions can be noted simply by looking at the amount of brain power devoted to such processing. Sensory information from all three spatial senses—vision, audition, and touch—is integrated in the posterior parietal cortex, which constitutes about 20% of the cerebral cortex. The parietal lobes send output to motor ...