Published online by Cambridge University Press: 30 November 2019
The human brain’s motor system, including the motor cortex and corticospinal system, the premotor cortex, basal ganglia, and cerebellum, together with input from sensory and polymodal association cortex, can program almost an infinite number of actions. Therefore, to successfully interact with the environment and ourselves we need the guidance provided by motor programs. There are two major forms of programs, action-intentional (the “when” system) and motor-praxic (the “how” system). The action-intentional system programs when to initiate an action, persist at an action, and terminate an action, or when not to act. The motor-praxic system programs the postures and joint movements required for correct interactions, as well as the speed, force, and sequence of these actions. This chapter describes how different elements of these two major forms of motor programs change with aging as well as the influence of aging on motor learning. The mechanisms that induce the aging-related changes in motor programming, motor skill learning, and motor performance are not fully known; however, in this chapter we discuss the various types of aging-related changes, their possible mechanisms, and how some of the changes can be limited and/or treated.