We studied relations between eye movements and postural control. In two experiments, participants were asked to shift gaze to follow horizontal oscillation of visual targets. Postural sway variability was reduced during target oscillation, relative to sway with a stationary target. Target displacement amplitude was within the range that normally does not elicit head rotation, and measured head rotation did not increase during target motion. Eye movements made when the eyes were closed did not yield a reduction in body sway (relative to sway when the closed eyes were stationary). The amplitude and frequency of eye movements matched the amplitude and frequency of target motion. The results undermine the view that eye movements and postural control compete for limited central processing resources, and document a functional integration of postural control with visual performance.
Bibliographical noteFunding Information:
Preparation of this article was supported by Enactive Interfaces, a network of excellence (IST Contract No. 002114) of the Commission of the European Community; the National Science Foundation (BCS-0236627, INT-9603315); the University of Paris XI; and the Institut Universitaire de France. Experiment 1 was conducted as part of Randy J. Pagulayan’s doctoral dissertation. We thank Michael A. Riley for comments on a draft of this article; Philip Hove, Omar Merhi, Valerie Neverman, Didier Casalta, Delphine Bernardin, and Olivier Oullier for their help with data collection and analysis; Dave Irwin for conversations and encouragement regarding this project; and Albert Gaudin, who provided the AMTI force plate.