ROTATING OBJECTS TO RECOGNIZE THEM - A CASE-STUDY ON THE ROLE OF VIEWPOINT DEPENDENCY IN THE RECOGNITION OF 3-DIMENSIONAL OBJECTS

Successful object recognition is essential for finding food, identifyi ng kin, and avoiding danger, as well as many other adaptive behaviors. To accomplish this feat, the visual system must reconstruct 3-D inter pretations from 2-D ''snapshots'' falling on the retina. Theories of r ecognition address this process by focusing on the question of how obj ect representations are encoded with respect to viewpoint. Although em pirical evidence has been equivocal on this question, a growing body o f surprising results, including those obtained in the experiments pres ented in this case study, indicates that recognition is often viewpoin t dependent. Such findings reveal a prominent role for viewpoint-depen dent mechanisms and provide support for the multiple-views approach, i n which objects are encoded as a set of view-specific representations that are matched to percepts using normalization procedures.