Attention, Perception, & Psychophysics

, Volume 76, Issue 3, pp 780–792 | Cite as

The global slowdown effect: Why does perceptual grouping reduce perceived speed?

  • Peter Jes KohlerEmail author
  • Gideon Paul Caplovitz
  • Peter Ulric Tse


The percept of four rotating dot pairs is bistable. The “local percept” is of four pairs of dots rotating independently. The “global percept” is of two large squares translating over one another (Anstis & Kim 2011). We have previously demonstrated (Kohler, Caplovitz, & Tse 2009) that the global percept appears to move more slowly than the local percept. Here, we investigate and rule out several hypotheses for why this may be the case. First, we demonstrate that the global slowdown effect does not occur because the global percept is of larger objects than the local percept. Second, we show that the global slowdown effect is not related to rotation-specific detectors that may be more active in the local than in the global percept. Third, we find that the effect is also not due to a reduction of image elements during grouping and can occur with a stimulus very different from the one used previously. This suggests that the effect may reflect a general property of perceptual grouping. Having ruled out these possibilities, we suggest that the global slowdown effect may arise from emergent motion signals that are generated by the moving dots, which are interpreted as the ends of “barbell bars” in the local percept or the corners of the illusory squares in the global percept. Alternatively, the effect could be the result of noisy sources of motion information that arise from perceptual grouping that, in turn, increase the influence of Bayesian priors toward slow motion (Weiss, Simoncelli, & Adelson 2002).


Motion Integration perceptual organization Grouping and Segmentation 

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  1. Adelson, E. H., & Movshon, J. A. A. (1982). Phenomenal coherence of moving visual patterns. Nature, 300(5892), 523–525.PubMedCrossRefGoogle Scholar
  2. Anstis, S. (2003). Levels of motion perception. In L. Harris & M. Jenkin (Eds.), Levels of perception (pp. 75–99). New York: Springer.Google Scholar
  3. Anstis, S., & Kim, J. (2011). Local versus global perception of ambiguous motion displays. Journal of Vision, 11(3), 13.PubMedCrossRefGoogle Scholar
  4. Ben-Av, M. B., Sagi, D., & Braun, J. (1992). Visual attention and perceptual grouping. Perception & Psychophysics, 52(3), 277–294.CrossRefGoogle Scholar
  5. Bex, P. J., & Makous, W. (1997). Radial motion looks faster. Vision Research, 37(23), 3399–3405.PubMedCrossRefGoogle Scholar
  6. Bex, P. J., Metha, A. B., & Makous, W. (1998). Psychophysical evidence for a functional hierarchy of motion processing mechanisms. Journal of the Optical Society of America. A, 15(4), 769–776.CrossRefGoogle Scholar
  7. Blair, C. D., Goold, J., Killebrew, K., & Caplovitz, G. P. (2013). Form features provide a cue to the angular velocity of rotating objects. Journal of Experimental Psychology. Human Perception and Performance. doi: 10.1037/a0033055
  8. Braddick, O. (1993). Segmentation versus integration in visual motion processing. Trends in neurosciences, 16(7), 263–268.PubMedCrossRefGoogle Scholar
  9. Brown, J. F. F. (1931). The visual perception of velocity. Psychologische Forschung, 14(1), 199–232.CrossRefGoogle Scholar
  10. Burr, D., & Thompson, P. (2011). Motion psychophysics: 1985-2010. Vision Research, 51(13), 1431–1456.PubMedCrossRefGoogle Scholar
  11. Caplovitz, G. P., Hsieh, P. J., & Tse, P. U. (2006). Mechanisms underlying the perceived angular velocity of a rigidly rotating object. Vision Research, 46(18), 2877–2893.Google Scholar
  12. Caplovitz, G. P., Paymer, N. A., & Tse, P. U. (2008). The Drifting Edge Illusion: a stationary edge abutting an oriented drifting grating appears to move because of the “other aperture problem”. Vision Research, 48(22), 2403–2414.PubMedCrossRefGoogle Scholar
  13. Caplovitz, G. P., & Tse, P. U. (2007a). Rotating dotted ellipses: motion perception driven by grouped figural rather than local dot motion signals. Vision Research, 47(15), 1979–1991.CrossRefGoogle Scholar
  14. Caplovitz, G. P., & Tse, P. U. (2007b). V3A processes contour curvature as a trackable feature for the perception of rotational motion. Cerebral cortex, 17, 1179–1189.CrossRefGoogle Scholar
  15. Carrasco, M., Ling, S., & Read, S. (2004). Attention alters appearance. Nature Neuroscience, 7(3), 308–313.PubMedCrossRefGoogle Scholar
  16. Clifford, C. W., Beardsley, S. A., & Vaina, L. M. (1999). The perception and discrimination of speed in complex motion. Vision research, 39(13), 2213–2227.PubMedCrossRefGoogle Scholar
  17. Fang, F., Kersten, D., & Murray, S. O. (2008). Perceptual grouping and inverse fMRI activity patterns in human visual cortex. Journal of Vision, 8(7), 2.1–9.CrossRefGoogle Scholar
  18. Geesaman, B. J., & Qian, N. (1996). A novel speed illusion involving expansion and rotation patterns. Vision Research, 36(20), 3281–3292.PubMedCrossRefGoogle Scholar
  19. Geesaman, B. J., & Qian, N. (1998). The effect of complex motion pattern on speed perception. Vision research, 38(9), 1223–1231.PubMedCrossRefGoogle Scholar
  20. Graziano, M. S., Andersen, R. A., & Snowden, R. J. (1994). Tuning of MST neurons to spiral motions. The Journal of Neuroscience, 14(1), 54–67.PubMedGoogle Scholar
  21. Hildreth, E. C., & Ullman, S. (1982). The measurement of visual motion. MIT AI memo, 699, 1–25.Google Scholar
  22. Hsieh, P.-J., & Tse, P. U. (2007). Grouping inhibits motion fading by giving rise to virtual trackable features. Journal of experimental psychology. Human perception and performance, 33(1), 57–63.PubMedCrossRefGoogle Scholar
  23. Johansson, G. (1973). Visual perception of biological motion and a model for its analysis. Perception & Psychophysics, 14(2), 201–211.CrossRefGoogle Scholar
  24. Kanizsa, G. (1979). Organization in vision: Essays on Gestalt perception. New York: Praeger.Google Scholar
  25. Kohler, P. J., Caplovitz, G. P., Hsieh, P.-J., Sun, J., & Tse, P. U. (2010). Motion fading is driven by perceived, not actual angular velocity. Vision Research, 50(11), 1086–1094.PubMedCrossRefGoogle Scholar
  26. Kohler, P. J., Caplovitz, G. P., & Tse, P. U. (2009). The whole moves less than the spin of its parts. Attention, Perception, & Psychophysics, 71(4), 675–679.CrossRefGoogle Scholar
  27. Köhler, W. (1969). The Task of Gestalt Psychology. Princeton: Princeton University Press.Google Scholar
  28. Liu, T., Abrams, J., & Carrasco, M. (2009). Voluntary attention enhances contrast appearance. Psychological Science, 20(3), 354–362.PubMedCentralPubMedCrossRefGoogle Scholar
  29. Lorenceau, J., & Alais, D. (2001). Form constraints in motion binding. Nature Neuroscience, 4(7), 745–751.PubMedCrossRefGoogle Scholar
  30. Lorenceau, J., & Shiffrar, M. (1992). The influence of terminators on motion integration across space. Vision research, 32(2), 263–273.PubMedCrossRefGoogle Scholar
  31. McDermott, J., & Adelson, E. H. (2004). Motion perception and mid-level vision. In M. S. Gazzaniga (Ed.), The Cognitive Neurosciences III (pp. 369–383). Boston: MIT Press.Google Scholar
  32. McDermott, J., Weiss, Y., & Adelson, E. H. (2001). Beyond junctions: nonlocal form constraints on motion interpretation. Perception, 30(8), 905–923.PubMedCrossRefGoogle Scholar
  33. Moore, C. M., & Egeth, H. (1997). Perception without attention: evidence of grouping under conditions of inattention. Journal of Experimental Psychology. Human Perception and Performance, 23(2), 339–352.PubMedCrossRefGoogle Scholar
  34. Murray, S. O., Kersten, D., Olshausen, B. A., Schrater, P., & Woods, D. L. (2002). Shape perception reduces activity in human primary visual cortex. Proceedings of the National Academy of Sciences of the United States of America, 99(23), 15164–15169.PubMedCentralPubMedCrossRefGoogle Scholar
  35. Nakayama, K., & Silverman, G. H. (1988a). The aperture problem–I. Perception of nonrigidity and motion direction in translating sinusoidal lines. Vision Research, 28(6), 739–746.Google Scholar
  36. Nakayama, K., & Silverman, G. H. (1988b). The aperture problem–II. Spatial integration of velocity information along contours. Vision Research, 28(6), 747–753.Google Scholar
  37. Reavis, E. A., Kohler, P. J., Caplovitz, G. P., Wheatley, T. P., & Tse, P. U. (2013). Effects of attention on visual experience during monocular rivalry. Vision Research, 83, 76–81.PubMedCrossRefGoogle Scholar
  38. Tadin, D., Lappin, J. S., Gilroy, L. A., & Blake, R. (2003). Perceptual consequences of centre-surround antagonism in visual motion processing. Nature, 424(6946), 312–315.PubMedCrossRefGoogle Scholar
  39. Tadin, D., Paffen, C. L. E., Blake, R., & Lappin, J. S. (2008). Contextual modulations of center-surround interactions in motion revealed with the motion aftereffect. Journal of Vision, 8(7), 9.1–11.CrossRefGoogle Scholar
  40. Tanaka, K., & Saito, H. (1989). Analysis of motion of the visual field by direction, expansion/contraction, and rotation cells clustered in the dorsal part of the medial superior temporal area of the macaque monkey. Journal of Neurophysiology, 62(3), 626–641.PubMedGoogle Scholar
  41. Thornton, T., & Gilden, D. L. (2001). Attentional limitations in the sensing of motion direction. Cognitive Psychology, 43(1), 23–52.PubMedCrossRefGoogle Scholar
  42. Treue, S., Husain, M., & Andersen, R. A. (1991). Human perception of structure from motion. Vision Research, 31(1), 59–75.PubMedCrossRefGoogle Scholar
  43. Turatto, M., Vescovi, M., & Valsecchi, M. (2007). Attention makes moving objects be perceived to move faster. Vision Research, 47(2), 166–178.PubMedCrossRefGoogle Scholar
  44. Uttal, W. R., Spillmann, L., Stürzel, F., & Sekuler, A. B. (2000). Motion and shape in common fate. Vision Research, 40(3), 301–310.PubMedCrossRefGoogle Scholar
  45. Verghese, P., & McKee, S. P. (2006). Motion grouping impairs speed discrimination. Vision Research, 46(8–9), 1540–1546.PubMedCrossRefGoogle Scholar
  46. Verghese, P., & Stone, L. S. (1996). Perceived visual speed constrained by image segmentation. Nature, 381(6578), 161–163.PubMedCrossRefGoogle Scholar
  47. Verghese, P., & Stone, L. S. (1995). Combining speed information across space. Vision Research, 35(20), 2811–2823.PubMedCrossRefGoogle Scholar
  48. Verghese, P., & Stone, L. S. (1997). Spatial layout affects speed discrimination. Vision Research, 37(4), 397–406.PubMedCrossRefGoogle Scholar
  49. Wallach, H., & O’Connell, D. N. (1953). The kinetic depth effect. Journal of Experimental Psychology, 45(4), 205–217.PubMedCrossRefGoogle Scholar
  50. Weiss, Y., Simoncelli, E., & Adelson, E. H. (2002). Motion illusions as optimal percepts. Nature Neuroscience, 5(6), 598–604.PubMedCrossRefGoogle Scholar

Copyright information

© Psychonomic Society, Inc. 2014

Authors and Affiliations

  • Peter Jes Kohler
    • 1
    Email author
  • Gideon Paul Caplovitz
    • 2
  • Peter Ulric Tse
    • 1
  1. 1.Department of Psychological and Brain SciencesDartmouth CollegeHanoverUSA
  2. 2.Department of PsychologyUniversity of Nevada, RenoRenoUSA

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