Visual control of arm movements requires a transformation between the retinal input, which depends on the direction of gaze, and the motor command sent to the arm muscles, which must be specified relative to the torso and arm. This visuomotor transformation is geometrically complex and needs to account for eye and head rotations as well as for the relative locations of the eyes, head, and shoulder. This article reviews current findings suggesting that distributed neural mechanisms perform this spatial transformation by comparing visual information with eye, head, and arm position signals.
