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Journal of the Optical Society of America A

Journal of the Optical Society of America A


  • Vol. 20, Iss. 8 — Aug. 1, 2003
  • pp: 1461–1471

Factors affecting motion integration

Gunter Loffler and Harry S. Orbach  »View Author Affiliations

JOSA A, Vol. 20, Issue 8, pp. 1461-1471 (2003)

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The perceived direction of motion of a featureless contour inside a circular aperture is always perpendicular to the contour’s orientation, regardless of its true motion (the aperture problem). This study investigates the circumstances under which unambiguous feature motion (of line terminators, single dots, or truncations of a D6 pattern) in adjacent apertures can alter the perceived direction of such featureless contours. We find that integration mechanisms responsible for motion capture are fairly robust against misorientations and contrast manipulations of individual components, are sensitive to differences in spatial frequencies, and scale with pattern size. Motion capture is not diminished when a D6 profile is substituted for the square-pulse profile of a line and is independent of the visibility of the apertures, indicating that object interpretations and three-dimensional analyses of a scene are less important than has been postulated previously. These results have strong implications for the neuronal hardware underlying the integration of motion signals across space and provide a framework for global motion models.

© 2003 Optical Society of America

OCIS Codes
(330.4150) Vision, color, and visual optics : Motion detection
(330.5380) Vision, color, and visual optics : Physiology
(330.7310) Vision, color, and visual optics : Vision

Gunter Loffler and Harry S. Orbach, "Factors affecting motion integration," J. Opt. Soc. Am. A 20, 1461-1471 (2003)

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  1. This paper is concerned with motion in the two-dimensional frontoprallel plane; the term “rigidity” (or coherence) describes the perception of a single rigid object moving in this plane.
  2. E. H. Adelson and J. A. Movshon, “Phenomenal coherence of moving visual patterns,” Nature 300, 523–525 (1982).
  3. V. P. Ferrera and H. R. Wilson, “Perceived direction of moving two-dimensional patterns,” Vision Res. 30, 273–287 (1990).
  4. L. S. Stone, A. B. Watson, and J. B. Mulligan, “Effect of contrast on the perceived direction of a moving plaid,” Vision Res. 30, 1049–1067 (1990).
  5. C. Yo and H. R. Wilson, “Perceived direction of moving two-dimensional patterns depends on duration, contrast and eccentricity,” Vision Res. 32, 135–147 (1992).
  6. K. Nakayama and G. H. Silverman, “The aperture problem I. Perception of nonrigidity and motion direction in translating sinusoidal lines,” Vision Res. 28, 739–746 (1988).
  7. M. Shiffrar and M. Pavel, “Percepts of rigid motion within and across apertures,” J. Exp. Psychol. Hum. Percept. Perform. 17, 749–761 (1991).
  8. J. Lorenceau and M. Shiffrar, “The influence of terminators on motion integration across space,” Vision Res. 32, 263–273 (1992).
  9. H. Wallach, “Über visuell wahrgenommene Bewegungsrichtung,” Psychol. Forsch. 20, 325–380 (1935).
  10. M. B. Ben-Av and M. Shiffrar, “When ambiguous becomes unambiguous,” Invest. Ophthalmol. Visual Sci. 34, 1028 (1993).
  11. E. Mingolla, J. T. Todd, and J. F. Norman, “The perception of globally coherent motion,” Vision Res. 32, 1015–1031 (1992).
  12. H. S. Orbach and H. R. Wilson, “Fourier and non-Fourier terminators in motion perception,” Invest. Ophthalmol. Visual Sci. 35, 1827 (1994).
  13. M. Shiffrar, X. Li, and J. Lorenceau, “Motion integration across differing image features,” Vision Res. 35, 2137–2146 (1995).
  14. F. L. Kooi, “Local direction of edge motion causes and abolishes the barberpole illusion,” Vision Res. 33, 2347–2351 (1993).
  15. J. Lorenceau, M. Shiffrar, N. Wells, and E. Castet, “Different motion sensitive units are involved in recovering the direction of moving lines,” Vision Res. 33, 1207–1217 (1993).
  16. W. H. Swanson, H. R. Wilson, and S. C. Giese, “Contrast matching data predicted from contrast increment thresholds,” Vision Res. 24, 63–75 (1984).
  17. G. Loffler and H. S. Orbach, “Anisotropy in judging the absolute direction of motion,” Vision Res. 41, 3677–3692 (2001).
  18. To avoid confusion, there is, of course, no “real” motion for a translating line presented on a monitor. Rather, the successive switching on and off of pixels creates the illusion of motion. So when we are talking about the real motion of a rigid line, this should be understood as the motion of the rigid object that could produce the stimulation.
  19. M. B. Ben-Av and M. Shiffrar, “Disambiguating velocity estimates across image space,” Vision Res. 35, 2889–2895 (1995).
  20. S. Shimojo, G. H. Silverman, and K. Nakayama, “Occlusion and the solution to the aperture problem for motion,” Vision Res. 29, 619–626 (1989).
  21. S. Grossberg and E. Mingolla, “Neural dynamics of motion perception: direction fields, apertures, and resonant grouping,” Percept. Psychophys. 53, 248–278 (1993).
  22. E. Peterhans and R. Von der Heydt, “Mechanisms of contour perception in monkey visual-cortex. 2. Contours bridging gaps,” J. Neurosci. 9, 1749–1763 (1989).
  23. The space constants of the fitted Gaussians are 2.8° for the D6 patterns and 2.1° for lines. The (albeit small) difference in space constants would be even further reduced by fixing the asymptotes of the Gaussians to 45° (the expected value of perpendicular motion for an isolated line segment).
  24. Obviously, this does not prove that higher-order processes cannot influence motion integration in addition to the low-level processes indicated here.
  25. One may argue that a quantitative comparison between this and previous experiments should take the distance between the dot and the closest part of the line segment as a substitute for the inter-aperture gap. However, even given this correction, the results in this experiment still show a bias that is significantly closer to the perpendicular than for line terminators.
  26. R. L. DeValois, E. W. Yund, and N. Hepler, “The orientation and direction selectivity of cells in macaque visual cortex,” Vision Res. 22, 531–544 (1982).
  27. Note that the 1.7-cpd flanker frequency condition here (Fig. 9) is not identical to the previous experiment on D6 patterns (Fig. 7). In the previous experiment, the contrast for the central patch and the truncations were equal but had opposite signs. Here the contrasts of the three parts of the display were identical. This gives the impression of a set of aligned, but disconnected, black and white stripes, which might be predicted to appear more coherent than in the case of contrast-alternated stripes used before. The results show that this manipulation does not greatly affect observers’ judgments.
  28. E. Castet and S. Wuerger, “Perception of moving lines: interactions between local perpendicular signals and 2D motion signals,” Vision Res. 37, 705–720 (1997).
  29. L. Liden and E. Mingolla, “Monocular occlusion cues alter the influence of terminator motion in the barber pole phenomenon,” Vision Res. 38, 3883–3898 (1998).
  30. N. Rubin and S. Hochstein, “Isolating the effect of one-dimensional motion signals on the perceived direction of moving 2-dimensional objects,” Vision Res. 33, 1385–1396 (1993).
  31. G. Vallortigara and P. Bressan, “Occlusion and the perception of coherent motion,” Vision Res. 31, 1967–1978 (1991).
  32. Note that, although the apertures in our experiments were invisible, such “pseudoreal” aperture terminators could conceivably be classified as extrinsic. This is because the apertures are physically absent in the sense of having zero contrast, but, as the line moves, the terminators trace out the shape of the aperture. (This possibility was raised, in conversation, by Mark Georgeson). The visual system could use this information to classify the terminator as arising from a line occluded by a circular aperture and hence be extrinsic in an elaborated intrinsic/extrinsic classification. To test this, the circular apertures were replaced with invisible rectangles in a control condition. The orientation of the rectangular apertures was perpendicular to the line’s orientation. This eliminated any difference between real and pseudoreal terminators. Nonetheless, the pattern of response was indistinguishable from that presented in Fig. 3, invalidating such a hypothesized modification of the intrinsic/extrinsic rule.
  33. J. B. Mulligan, “A continuous version of the barber-pole illusion,” Invest. Ophthalmol. Visual Sci. 32, 829 (1991).
  34. G. Loffler, “The integration of motion signals across space,” Ph.D. thesis (Glasgow Caledonian University, Glasgow, UK, 1999).
  35. G. Loffler and H. S. Orbach, “Modeling the integration of motion signals across space,” J. Opt. Soc. Am. A 20, 1472–1489 (2003).
  36. Y. Weiss and E. H. Adelson, “Integration and segmentation of nonrigid motion,” Invest. Ophthalmol. Visual Sci. 36, S228 (1995).
  37. H. S. Orbach and G. Loffler, “What determines motion integration across apertures?” Invest. Ophthalmol. Visual Sci. 41, 2889 (2000).

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