The selective utilization of information in the optic array

Summary When ambulatory subjects wear prisms with bases vertically opposed before the two eyes, the direction of the after-effect measured on a localization task shows that there is a bias favouring selection of the field which contains more of the floor. Subjects allowed differential views of the floor with prism bases laterally opposed also show this bias. The bias is reversed if flow patterns from the lower visual field are eliminated. These studies support the view that information in the lower ambient field is selectively utilized during locomotion.This research was supported by Grant No. APA-1 from the National Research Council of Canada. Experiment 4 and a first replication of Experiment 1 were part of a thesis submitted by the junior author for the M.A. degree at the University of Toronto.