ORIENTATION PRIMING OF NOVEL SHAPES IN THE CONTEXT OF VIEWPOINT-DEPENDENT RECOGNITION

Can visual similarity between shapes facilitate orientation priming? F ive experiments are reported in which this possibility was explored by using novel two-dimensional shapes that formed homogeneous stimulus c lasses. After training on individual shapes in a canonical view, the r ecognition of these shapes was tested in several picture-plane orienta tions. In experiments 1 and 2 an identification task was used to repli cate the classic finding obtained with the mirror-judgment task-that p rior orientation cueing does not reduce the magnitude of orientation d ependence in processing rotated shapes. The results of experiment 3, h owever, indicate that blocking trials by orientation is one condition in which orientation priming may be obtained. Experiment 4 builds on t his result, and it is suggested that awareness of the blocking manipul ation is not required to obtain orientation priming. In experiment 5 t he mechanisms underlying this finding are explored, and evidence is of fered that orientation priming is a consequence of representations tha t encode both shape and orientation. Such results may be considered as an extension to the 'image-based' approach to object recognition, dem onstrating that generalization across exemplars may occur within recog nition mechanisms that are viewpoint dependent.