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 degrees between presentations. When the 180 degrees rotation resulted in large changes in depth for object components, recognition performance in the mono condition showed better performance at 180 degrees rotations than at smaller rotations, but stereo presentations showed a monotonic increase in response time with rotation. However, 180 degrees 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.