Goal-directed movement is central to the relationship between brain and behavior in humans and other animals. This book presents a detailed investigation of the topic, one that integrates psychology and physiology. The author's account is based on a large body of experimental data from human and animal work, with particular emphasis on clinical cases. It probes such questions as: Are complex movements organized on the same mode as simple ones? How rigidly organized are coordinated actions like orienting or grasping? Where do visual feedback signals arise? The author's work takes into account the growing acceptance of the idea that movements are not directly dependent upon sensory events, but that they are governed by internal representations which are built according to specific, experimentally accessible rules.