Oculocentrically organized arm movement-related activity in the primate superior colliculus

The seemingly simple act of reaching to a target requires complex integration and transformation of spatial information both for the control of the eve and the arm, For efficiently dealing with the outside world both motor systems must interact in a well-coordinated manner, Mutal influences of the two systems were found in neurons of various parts of the parietal and premotor cortex. Also in and below the Superior Colliculus, a well-established oculomotor structure, a substantial population of cells is involved in the control of goal-directed arm movements. We present here evidence that some of the neurons with reach-related activity in the SC are specifically sensitive to the vector between gaze asis and reach target. These neurons could signal either the target for the reach or the motor error between foveated target and reached target in a gaze-centered coordinate system and therefore might represent a neuronal substrate for eye-hand coordination in humans and other primates.