11 - Control of goal-directed limb movements in primates: neurobiological evidence for parallel, distributed motor processing

Abstract

Publisher Summary The control of goal-directed limb movements requires that the target or goal of each movement be translated quickly and efficiently into an appropriate set of muscle activation patterns that will carry the limb along the required trajectory. The control of goal-directed limb movements in three-dimensional space represents an enormously complex challenge to the motor system. Theorists have embraced the concept of the motor program in an attempt to account for the remarkable speed and flexibility of skilled motor behaviors. However, fundamental issues regarding the origin and nature of motor programs have yet to be addressed in detail. This chapter focuses on the parallel distributed processing (PDP) models of motor control, which represent an exciting new approach to the study of the neural substrates of motor behavior. Such models provide detailed and testable hypotheses concerning the neural basis for the complex and highly adaptive motor behavior of primates. Recent neurophysiological investigations of the motor system in awake, behaving primates have shown that each of three interconnected motor areas contains neural representations of several different levels of motor processing. The concept of parallel distributed motor processing represents an important theoretical advance in the study of the neural control of movement. PDP approaches to neural modeling will very likely provide the first detailed, testable, and neurobiologically relevant models of motor processing in primates.