ABSTRACT
This chapter focuses on possible ways in which the central nervous system (CNS) may produce the forces necessary to generate movements. It considers the problems presented by kinematic redundancy. The chapter shows how motor memories may be represented, stored, and retrieved through the formation of internal models of limb dynamics. It reviews some of the neurophysiological evidence that suggests that motor learning consists of tuning the activity of a relatively small group of neurons. Each of these groups constitutes a "module," which combines with others to produce a vast repertoire of motor behaviors. The chapter presents a theory based on internal models to explain how the CNS controls limb dynamics. Through repeated exposure to sensory signals coming from the moving limb during the acquisition of a motor task, there is a gradual change in the synaptic strength of the neurons of the motor areas.
