THE VISUAL-PERCEPTION OF 3-DIMENSIONAL SHAPE FROM SELF-MOTION AND OBJECT-MOTION

To evaluate the influence of egomotion on the three-dimensional visual processing of structure-from-motion (SFM), we compared the visual dis crimination between planar and spherical surfaces during subject-trans lation, object-translation, or rotation of the object in depth. Perfor mance was the best for object-rotation, intermediate for subject-trans lation, and the poorest for object-translation-and thus increased with the quality of retinal image stabilization achieved in the different conditions. This suggests that the major role of self-motion informati on was to stabilize retinal images. In view of previous results, we pr opose that the interactions between self-motion information and SFM ar e reduced to functional complementarity, in the sense that self-motion can lift visual ambiguities but does not improve the sensitivity of S FM processes.