Cite as:
McDermott J, Weiss Y, Adelson E H, 2001, "Beyond junctions: nonlocal form constraints on motion interpretation" Perception 30(8) 905 – 923
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Beyond junctions: nonlocal form constraints on motion interpretation

Josh McDermott, Yair Weiss, Edward H Adelson

Received 6 June 2000, in revised form 28 January 2001

Abstract. Because of the aperture problem, local motion measurements must be combined across space. However, not all motions should be combined. Some arise from distinct objects and should be segregated, and some are due to occlusion and should be discounted because they are spurious. Humans have little difficulty ignoring spurious motions at occlusions and correctly integrating object motion, and are evidently making use of form information to do so. There is a large body of theoretical and empirical evidence supporting the importance of form processes involving junctions in the way motion is integrated. To assess the role of more complex form analysis, we manipulated nonlocal form cues that could be varied independently of local junctions. Using variants on diamond and plaid stimuli used in previous studies, we found that manipulations distant from the junctions themselves could cause large changes in motion interpretation. Nonlocal information often overrides the integration decisions that would be expected from local cues. The mechanisms implicated appear to involve surface segmentation, amodal completion, and depth ordering.

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 References  44 references, 27 with DOI links ()

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