Cross-modal slant and curvature matching of stereo- and motion-induced surfaces.
In many laboratory setups and in many day-to-day situations, a unique solution of the structure-from-two-views problem is unobtainable. Yet, when the visual system is presented with two projections in a sequence, it nevertheless appears to generate a reasonably stable percept of structure. In the research reported here, we examined whether the same surface would be perceived when subjects were presented with a pair of views that alternated in time monocularly (two-frame motion) or were shown simultaneously to both eyes (stereo). In Experiment 1, we studied slant perception: human observers were asked to match the slant of a motion-induced planar surface with its stereo-induced counterpart. In Experiment 2, the perceived curvature of parabolic surfaces was matched in a similar way. The results show that motion-induced slant is matched with a higher value of the stereo-induced slant. However, the curvature experiment showed that motion-induced curvature is matched with a lower stereo-induced curvature. One possible explanation may be that the slant and curvature are internally inconsistent in at least one of the modalities.
Utrecht Biophysics Research Institute, The Netherlands.
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de Vries
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Werkhoven
D001288:Attention; D003463:Cues; D003867:Depth Perception; D005556:Form Perception; D006801:Humans; D009039:Motion Perception; D009903:Optical Illusions; D009949:Orientation; D011340:Problem Solving; D011601:Psychophysics