A robotics approach for interpreting the gaze-related modulation of the activity of premotor neurons during reaching

This paper deals with the modeling of the activity of premotor neurons associated with the execution of a visually guided reaching movement in primates. We address this question from a robotics point of view, by considering a simplified kinematic model of the head, eye and arm joints. By using the formalism of visual servoing, we show that the hand controller depends on the direction of the head and the eye, as soon as the hand-target difference vector is expressed in eye-centered coordinates. Based on this result, we propose a new interpretation of previous electrophysiological recordings in monkey, showing the existence of a gaze-related modulation of the activity of premotor neurons during reaching. This approach sheds a new light on this phenomenon which, so far, is not clearly understood.