Visual adaptation alters the apparent speed of real-world actions

The apparent physical speed of an object in the field of view remains constant despite variations in retinal velocity due to viewing conditions (velocity constancy). For example, people and cars appear to move across the field of view at the same objective speed regardless of distance. In this study a series of experiments investigated the visual processes underpinning judgements of objective speed using an adaptation paradigm and video recordings of natural human locomotion. Viewing a video played in slow-motion for 30 seconds caused participants to perceive subsequently viewed clips played at standard speed as too fast, so playback had to be slowed down in order for it to appear natural; conversely after viewing fast-forward videos for 30 seconds, playback had to be speeded up in order to appear natural. The perceived speed of locomotion shifted towards the speed depicted in the adapting video (‘re-normalisation’). Results were qualitatively different from those obtained in previously reported studies of retinal velocity adaptation. Adapting videos that were scrambled to remove recognizable human figures or coherent motion caused significant, though smaller shifts in apparent locomotion speed, indicating that both low-level and high-level visual properties of the adapting stimulus contributed to the changes in apparent speed.

[1]  M. Morgan,et al.  Linking hypotheses underlying Class A and Class B methods , 2013, Visual Neuroscience.

[2]  O W SMITH,et al.  A new explanation of the velocity-transposition phenomenon. , 1957, The American journal of psychology.

[3]  George Mather,et al.  Changes in the apparent speed of human locomotion: norm-based coding of speed , 2015 .

[4]  R. L. Valois,et al.  The orientation and direction selectivity of cells in macaque visual cortex , 1982, Vision Research.

[5]  H. Wallach,et al.  On constancy of visual speed. , 1939 .

[6]  Derek H. Arnold,et al.  Visual Sensitivity Can Scale with Illusory Size Changes , 2010, Current Biology.

[7]  M. Webster.  Adaptation and visual coding. , 2011, Journal of vision.

[8]  W. Peddie.  Phenomenal Regression to the Real Object , 1933, Nature.

[9]  Derek H. Arnold,et al.  Spatially Localized Distortions of Event Time , 2006, Current Biology.

[10]  D. Kersten,et al.  The representation of perceived angular size in human primary visual cortex , 2006, Nature Neuroscience.

[11]  George Mather,et al.  Evidence for norm-based coding of human movement speed , 2016 .

[12]  Rebecca J Sharman,et al.  Decision-level adaptation in motion perception , 2015, Royal Society Open Science.

[13]  E. Wist,et al.  The spatial frequency effect on perceived velocity , 1976, Vision Research.

[14]  Zachary C. Burns,et al.  Slow motion increases perceived intent , 2016, Proceedings of the National Academy of Sciences.

[15]  G. Mather,et al.  Two Channels for Flicker in the Human Visual System , 1984, Perception.

[16]  M. Morgan,et al.  Observers can voluntarily shift their psychometric functions without losing sensitivity , 2011, Attention, Perception, & Psychophysics.

[17]  N. Troje.  Decomposing biological motion: a framework for analysis and synthesis of human gait patterns. , 2002, Journal of vision.

[18]  Keiji Tanaka,et al.  Inferotemporal cortex and object vision. , 1996, Annual review of neuroscience.

[19]  D. Alais,et al.  Evidence for two interacting temporal channels in human visual processing , 2006, Vision Research.

[20]  D H Brainard,et al.  The Psychophysics Toolbox. , 1997, Spatial vision.

[21]  George Mather,et al.  Is adaptation to human motion necessary to change the apparent speed of locomotion , 2015 .

[22]  N. Troje,et al.  Embodiment of Sadness and Depression—Gait Patterns Associated With Dysphoric Mood , 2009, Psychosomatic medicine.

[23]  D G Pelli,et al.  The VideoToolbox software for visual psychophysics: transforming numbers into movies. , 1997, Spatial vision.

[24]  D. Burr,et al.  Contrast sensitivity at high velocities , 1982, Vision Research.

[25]  Kevin Brownlow,et al.  Silent Films–What Was the Right Speed? , 1990 .

[26]  Leslie G. Ungerleider,et al.  Dissociation of object and spatial visual processing pathways in human extrastriate cortex. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[27]  Rebecca A. Champion,et al.  A ratio model of perceived speed in the human visual system , 2005, Proceedings of the Royal Society B: Biological Sciences.

[28]  R. Hess,et al.  Estimating multiple temporal mechanisms in human vision , 1998, Vision Research.

[29]  Armin Bruderlin,et al.  Perceiving affect from arm movement , 2001, Cognition.

[30]  T. J. Clarke,et al.  The Perception of Emotion from Body Movement in Point-Light Displays of Interpersonal Dialogue , 2005, Perception.

[31]  Stephen T. Hammett,et al.  The dynamics of velocity adaptation in human vision , 2000, Current Biology.

[32]  M. Webster,et al.  Adaptation and perceptual norms in color vision. , 2008, Journal of the Optical Society of America. A, Optics, image science, and vision.

[33]  R. Hess,et al.  Temporal frequency filters in the human peripheral visual field , 1992, Vision Research.

[34]  C. A. Burbeck,et al.  Locus of spatial-frequency discrimination. , 1987, Journal of the Optical Society of America. A, Optics and image science.

[35]  A. Young,et al.  Emotion Perception from Dynamic and Static Body Expressions in Point-Light and Full-Light Displays , 2004, Perception.

[36]  Keiji Tanaka,et al.  Neuronal selectivities to complex object features in the ventral visual pathway of the macaque cerebral cortex. , 1994, Journal of neurophysiology.