Over the past decade it has become increasingly clear that to understand the brain, we must study not only its biochemical and biophysical mechanisms and its outward perceptual and physical behavior. We also must study the brain at a theoretical level that investigated the computations that are necessary to perform its functions. The control of movements such as reaching, grasping and manipulating objects requires complex mechanisms that elaborate information form many sensors and control the forces generated by a large number of muscles. The act of seeing, which intuitively seems so simple and effortless, requires information processing whose complexity we are just beginning to grasp. A computational approach to the study of vision and motor tasks. This paper discusses a particular view of the computational approach and its relevance to experimental neuroscience.