Orientation in Trapezoid-Shaped Enclosures: Determination of Geometric Features Controlling Spatial Choice

Human participants learned to select one of four distinctively marked corners (i.e., red, yellow, blue and green) in a rectangular virtual enclosure. After training, test trials were interspersed with training trials. On test trials, all markers were equivalent in color (i.e., white) and the geometric structure of the enclosure was manipulated. For each test trial, a single long wall or short wall of the enclosure increased twice as long or half as long as the training enclosure. These manipulations produced eight unique trapezoid-shaped enclosures and one rectangular enclosure (i.e., control). participants were allowed to select only one corner during test trials. Selected corners during test rials revealed which geometric features of the enclosures were controlling choice behavior. For example, participants may have learned to approach 90 degree angles, a long-wall tot he left or white, a long-wall to the left or right, a ratio of long-to-short walls, or some combination of these geometric features. Results and theoretical implications will be discussed.