Accession Number : ADA295653

Title :   Pattern Motion Perception: Feature Tracking or Integration of Component Motions?

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB

Personal Author(s) : Sinha, Pawan

PDF Url : ADA295653

Report Date : OCT 1994

Pagination or Media Count : 8

Abstract : A key question regarding primate visual motion perception is whether the motion of 2D patterns is recovered by tracking distinctive localizable features Lorenceau and Gorea, 1989; Rubin and Hochstein, 1992 or by integrating ambiguous local motion estimates Adelson and Movshon, 1982; Wilson and Kim, 1992. For a two-grating plaid pattern, this translates to either tracking the grating intersections or to appropriately combining the motion estimates for each grating. Since both component and feature information are simultaneously available in any plaid pattern made of contrast defined gratings, it is unclear how to determine which of the two schemes is actually used to recover the plaid's motion. To address this problem, we have designed a plaid pattern made with subjective, rather than contrast defined, gratings. The distinguishing characteristic of such a plaid pattern is that it contains no contrast defined intersections that may be tracked. We find that notwithstanding the absence of such features, observers can accurately recover the pattern velocity. Additionally we show that the hypothesis of tracking 'illusory features' to estimate pattern motion does not stand up to experimental test These results present direct evidence in support of the idea that calls for the integration of component motions over the one that mandates tracking localized features to recover 2D pattern motion. The localized features, we suggest, are used primarily as providers of grouping information - which component motion signals to integrate and which not to.(MM)

Descriptors :   *MOTION, *PATTERN RECOGNITION, GRATINGS(SPECTRA), PATTERNS, ARTIFICIAL INTELLIGENCE, VISUAL PERCEPTION, OPTICAL TRACKING, ILLUSIONS.

Subject Categories : Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE