A stereo disadvantage for recognizing rotated familiar objects

We tested recognition of familiar objects in two different conditions: mono, where stimuli were displayed as flat, 2-D images, and stereo, where objects were displayed with stereoscopic depth information. In three experiments, participants performed a sequential matching task, where an object was rotated by up to 180° between presentations. When the 180° rotation resulted in large changes in depth for object components, recognition performance in the mono condition showed better performance at 180° rotations than at smaller rotations, but stereo presentations showed a monotonic increase in response time with rotation. However, 180° rotations that did not result in much depth variation showed similar patterns of results for mono and stereo conditions. These results suggest that in some circumstances, the lack of explicit 3-D information in 2-D images may influence the recognition of familiar objects when they are depicted on flat computer monitors.