Viewer-centered temporal biasing of 3-D rotation percepts

The perceived direction of rotation of a 3-D cloud of dots can be biased by a prior rotation (Jiang, Pantle, and Mark, 1998 Perception & Psychophysics 60 275-286). In a series of experiments, it is shown that the temporal rot ation bias is reversed by a 180 degrees change of head orientation between two rotation sequences; ie the perceived direction of rotation reverses for the second of two sequences when head orientation is changed. The bias is, therefore, viewer-centered. Perceptual reversals are not obtained when the orientation of the head is changed and returned to its original position b etween rotation sequences. It was also found that the viewer-centered bias combined additively with viewer-independent near-far luminance information. Finally, the bias was manifest when 3-D depth was re-established, bur not maintained, between rotation sequences. A model, in descriptive and flowcha rt forms, is used to explain the integration of world-centered information and a viewer-centered temporal bias on the presence/absence of perceptual r eversals of the rotating virtual sphere. In the model, the temporal bias is the result of the coupling of depth values to persisting 2-D retinal motio n signals.