Listing's Law for Gaze-Directing Head Movements

This chapter clarifies that "Listing's Law", which governs the rotations of voluntary eye movements, also governs specific types of voluntary head movements. Listing's law for the eye states that there is a "displacement plane" associated with the orientation assumed by the eye, and there is exactly one eye position p in which the displacement plane is orthogonal to the line of sight. The analogy of Listing's law for the head states that there is an associated displacement plane DPh such that the head assumes only those positions from the reference position by rotating about the axis lying on DPh. This chapter also presents the methods of the experiments performed on seven human subjects where their three-dimensional head position and velocity vectors were measured using Robinson's magnetic field-search coil technique. The primary finding of this study is the Listing's Law for the head.