Comprises the proceedings of a symposium held at the Ciba Foundation, London, February 1987. Addresses main issues and new techniques in the study of motor areas of the cerebral cortex in humans and animals. Reviews the historical development of the study of cortical structure and function, examines anatomical connections of motor areas, and surveys physiological studies of cortical areas in conscious primates. Also considers the effects of cortical lesions, and discusses clinical and experimental results on disorders of motor control.