Cast shadow can modulate the judged final position of a moving target

Observers tend to localize the final position of a suddenly vanished moving target farther along in the direction of the target motion (representational momentum). We report here that such localization errors are mediated by perceived motion rather than by retinal motion. By manipulating the cast shadow of a moving target, we induced illusory motion to a target stimulus while keeping the retinal motion constant. Participants indicated the vanishing point of the target by directing a mouse cursor. The resulting magnitude of localization errors was modulated on the basis of the induced direction of the target. Such systematic localization biases were not obtained in a control condition in which the motion paths of the ball and shadow were switched. Our results suggest that cues to object motion trajectory, such as cast shadows, are used for the localization task, supporting a view that a predictive mechanism is responsible for the production of localization errors.

[1]  D. Kerzel.  Representational Momentum Beyond Internalized Physics , 2005 .

[2]  T. A. Ryan,et al.  Significance tests for multiple comparison of proportions, variances, and other statistics. , 1960, Psychological bulletin.

[3]  J. Freyd,et al.  A velocity effect for representational momentum , 1985 .

[4]  Géry d'Ydewalle,et al.  Representational momentum and event course anticipation in the perception of implied periodical motions. , 1991, Journal of experimental psychology. Learning, memory, and cognition.

[5]  D. Kerzel.  Memory for the position of stationary objects: disentangling foveal bias and memory averaging , 2002, Vision Research.

[6]  Chris L. S. Coryn,et al.  Short-term memory , 1975 .

[7]  Jamshed J. Bharucha,et al.  Is judged displacement a modular process , 1994 .

[8]  T L Hubbard,et al.  The effect of context on visual representational momentum , 1993, Memory & cognition.

[9]  Dirk Kerzel,et al.  The role of perception in the mislocalization of the final position of a moving target. , 2001, Journal of experimental psychology. Human perception and performance.

[10]  Sonja Stork,et al.  Comparing mislocalizations with moving stimuli: The Fröhlich effect, the flash-lag, and representational momentum , 2002 .

[11]  T L Hubbard,et al.  Cognitive representation of motion: evidence for friction and gravity analogues. , 1995, Journal of experimental psychology. Learning, memory, and cognition.

[12]  D. Kerzel.  Eye movements and visible persistence explain the mislocalization of the final position of a moving target , 2000, Vision Research.

[13]  T. Takeuchi,et al.  Visual search of expansion and contraction , 1997, Vision Research.

[14]  Dirk Kerzel,et al.  Attention maintains mental extrapolation of target position: irrelevant distractors eliminate forward displacement after implied motion , 2003, Cognition.

[15]  K. Gegenfurtner,et al.  Neuronal Processing Delays Are Compensated in the Sensorimotor Branch of the Visual System , 2003, Current Biology.

[16]  Dirk Kerzel,et al.  Computational Theory and Cognition in Representational Momentum and Related Types of Displacement: A reply to Kerzel , 2006 .

[17]  T. Hubbard.  Cognitive representation of linear motion: Possible direction and gravity effects in judged displacement , 1990, Memory & cognition.

[18]  Masami K Yamaguchi,et al.  Asymmetry in the perception of motion-in-depth , 2004, Vision Research.

[19]  Takahiro Kawabe,et al.  Attention shift not memory averaging reduces foveal bias , 2005, Vision Research.

[20]  Akihiro Yagi,et al.  The pointedness effect on representational momentum , 2001, Memory & cognition.

[21]  Timothy L. Hubbard,et al.  Representational momentum and the landmark attraction effect. , 1999 .

[22]  T. L. Hubbard,et al.  Bridging the Gap: possible roles and contributions of representational momentum , 2006 .

[23]  Timothy L. Hubbard,et al.  Target size and displacement along the axis of implied gravitational attraction : Effects of implied weight and evidence of representational gravity , 1997 .

[24]  Akihiro Yagi,et al.  Asymmetry in the perception of motion in depth induced by moving cast shadows. , 2008, Journal of vision.

[25]  R A Finke,et al.  Implied velocity and acceleration induce transformations of visual memory. , 1986, Journal of experimental psychology. General.

[26]  J. Bharucha,et al.  Judged displacement in apparent vertical and horizontal motion , 1988, Perception & psychophysics.

[27]  Akihiro Yagi,et al.  Perception of motion trajectory of object from the moving cast shadow in infants , 2006, Vision Research.

[28]  D Kersten,et al.  Moving Cast Shadows Induce Apparent Motion in Depth , 1997, Perception.

[29]  T. Hubbard.  Representational momentum and related displacements in spatial memory: A review of the findings , 2005, Psychonomic bulletin & review.

[30]  T. Hubbard,et al.  Environmental invariants in the representation of motion: Implied dynamics and representational momentum, gravity, friction, and centripetal force , 1995, Psychonomic bulletin & review.

[31]  D. Knill,et al.  The perception of cast shadows , 1998, Trends in Cognitive Sciences.

[32]  Dirk Kerzel,et al.  Mental extrapolation of target position is strongest with weak motion signals and motor responses , 2003, Vision Research.

[33]  M. Nagai,et al.  Illusory motion and representational momentum , 2005, Perception & psychophysics.

[34]  M. Nagai,et al.  Larger forward memory displacement in the direction of gravity , 2002 .