Orientation in trapezoid-shaped enclosures: implications for theoretical accounts of geometry learning

Human participants learned to select 1 of 4 distinctively marked corners in a rectangular virtual enclosure. After training, control and test trials were interspersed with training trials. On control and test trials, all markers were equivalent in color, but only during test trials was the shape of the enclosure manipulated. Specifically, for each test trial, a single long wall or short wall of the enclosure increased twice as long as or decreased half as long as that present in the training enclosure. These manipulations produced 8 unique trapezoid-shaped enclosures. Participants were allowed to select 1 corner during control and test trials. Performance during control trials revealed that participants selected the correct and rotationally equivalent locations. Performance during test trials revealed that participants selected locations in trapezoid-shaped enclosures that were consistent with those predicted by global geometry (i.e., principal axis of space) but were inconsistent with those predicted by local geometry (i.e., proportion of rewarded training features present at a location). Results have implications for theoretical accounts of geometry learning.