Abstract
[Purpose] A gaze is directed to a point of interest in the visual field. Despite the fact that the shift of gaze is accomplished with combinations of eye, head and body movements, no studies, as far as we know, investigated the gaze control system under free head and body movements. The purpose of this study is to investigate the relationship between the eye and head movements for a natural task in a natural viewing condition: that is, during visual search in a 360°filed display. [Experiment] We measured participants’ eye, head and body movements while they were searching a target, T, among distractors, L, presented in a 360° visual display; six LCD displays surrounding the participant. The participant naturally moved his head, eyes, and body to search for the target and then pressed a button when he found the target. We analyzed the amplitude of the eye and head movements for each gaze shift to estimate contributions of the head and eye to gaze shift. [Results] Relative contributions of the head and eye varied with gaze size. When gaze shift amplitude is less than 40°, the contribution of head movements is less than 15% while it when it is over that range, the contribution of head becomes as much as 85%. [Discussion] We found that the contributions of head and eye movements to gaze shift systematically varies with gaze shift amplitude. A study with gaze shifts to a peripheral target reported similar effect of gaze shift size without clear contribution of head movements for small gaze shift. Our finding suggests that similar but not identical control of gaze shift may occur in the daily life as in the case of gaze shift to a peripheral stimulus.
Meeting abstract presented at VSS 2013