Poor Speed Discrimination Suggests that there is No Specialized Speed Mechanism for Cyclopean Motion

Luminance-defined and stereo-defined (cyclopean) motion share some common properties, suggesting that the two forms of motion may be detected by similar mechanisms. For luminance-defined motion there are at least two levels of processing: direction is detected and then speed is thought to be extracted by a specialized processing mechanism at a higher level. Here, we tested whether there is also a specialized speed processing mechanism for stereo-defined motion. Speed discrimination thresholds were compared for stimuli containing only stereo-defined motion, and stimuli that contained both stereo-defined and luminance-defined motion. When the stimulus contained luminance-defined motion, increment thresholds were around 0.05-0.1. For stereo-defined motion, increment thresholds were never better than 0.3. By careful analysis, it was possible to test what cues were being used to solve the speed discrimination task. Results were consistent with observers responding to distance cues rather than to speed for stereo-defined motion, suggesting that there is no specialized mechanism for processing the speed of stereo-defined motion.

[1]  R. Schumer,et al.  Independent stereoscopic channels for different extents of spatial pooling , 1979, Vision Research.

[2]  C. WILLIAM TYLER,et al.  Depth perception in disparity gratings , 1974, Nature.

[3]  Patrick Cavanagh.  Is there low-level motion processing for non-luminance-based stimuli? , 1995 .

[4]  E. Adelson,et al.  Directionally selective complex cells and the computation of motion energy in cat visual cortex , 1992, Vision Research.

[5]  S. McKee,et al.  Sequential recruitment in the discrimination of velocity. , 1985, Journal of the Optical Society of America. A, Optics and image science.

[6]  G. Sperling,et al.  Second-order motion perception: space/time separable mechanisms , 1989, [1989] Proceedings. Workshop on Visual Motion.

[7]  G. Mather,et al.  Evidence for second-order motion detectors , 1993, Vision Research.

[8]  T. Pasternak.  Discrimination of differences in speed and flicker rate depends on directionally selective mechanisms , 1987, Vision Research.

[9]  D J Heeger,et al.  Model for the extraction of image flow. , 1987, Journal of the Optical Society of America. A, Optics and image science.

[10]  K. Nakayama.  Differential motion hyperacuity under conditions of common image motion , 1981, Vision Research.

[11]  Patrick Cavanagh,et al.  Interattribute apparent motion , 1989, Vision Research.

[12]  S. Nishida,et al.  Motion aftereffect with flickering test patterns reveals higher stages of motion processing , 1995, Vision Research.

[13]  Robert Patterson,et al.  Properties of cyclopean motion perception , 1992, Vision Research.

[14]  D. G. Green,et al.  Optical and retinal factors affecting visual resolution. , 1965, The Journal of physiology.

[15]  David R. Badcock,et al.  Detecting the displacement of periodic patterns , 1985, Vision Research.

[16]  J. Movshon,et al.  Spatial and temporal contrast sensitivity of striate cortical neurones , 1975, Nature.

[17]  A. Pantle,et al.  On the mechanism that encodes the movement of contrast variations: Velocity discrimination , 1989, Vision Research.

[18]  T. Papathomas.  Early vision and beyond , 1995 .

[19]  Andrew T. Smith,et al.  Evidence for separate motion-detecting mechanisms for first- and second-order motion in human vision , 1994, Vision Research.

[20]  S. McKee.  A local mechanism for differential velocity detection , 1981, Vision Research.

[21]  G. Sperling,et al.  Drift-balanced random stimuli: a general basis for studying non-Fourier motion perception. , 1988, Journal of the Optical Society of America. A, Optics and image science.

[22]  A J Ahumada,et al.  Model of human visual-motion sensing. , 1985, Journal of the Optical Society of America. A, Optics and image science.

[23]  O J Braddick,et al.  Low-level and high-level processes in apparent motion. , 1980, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[24]  R. Holub,et al.  Response of Visual Cortical Neurons of the cat to moving sinusoidal gratings: response-contrast functions and spatiotemporal interactions. , 1981, Journal of neurophysiology.

[25]  J S Lappin,et al.  On the relation between time and space in the visual discrimination of velocity. , 1975, Journal of experimental psychology. Human perception and performance.

[26]  J. Gaddum.  Probit Analysis , 1948, Nature.

[27]  A. Yuille,et al.  A model for the estimate of local image velocity by cells in the visual cortex , 1990, Proceedings of the Royal Society of London. B. Biological Sciences.

[28]  David R. Badcock,et al.  Detecting the displacements of spatial beats: No role for distortion products , 1989, Vision Research.

[29]  B. Julesz,et al.  Differences between monocular and binocular stroboscopic movement perception. , 1968, Vision research.

[30]  Ken Nakayama,et al.  Biological image motion processing: A review , 1985, Vision Research.

[31]  Julie M. Harris,et al.  Speed discrimination of motion-in-depth using binocular cues , 1995, Vision Research.

[32]  E H Adelson,et al.  Spatiotemporal energy models for the perception of motion. , 1985, Journal of the Optical Society of America. A, Optics and image science.

[33]  R. Sekuler,et al.  Psychophysics of Motion Perception , 1982 .

[34]  B. Rogers,et al.  Similarities between motion parallax and stereopsis in human depth perception , 1982, Vision Research.

[35]  H. Wilson,et al.  A psychophysically motivated model for two-dimensional motion perception , 1992, Visual Neuroscience.

[36]  Jeounghoon Kim,et al.  Dependence of plaid motion coherence on component grating directions , 1993, Vision Research.

[37]  Leslie Welch,et al.  The perception of moving plaids reveals two motion-processing stages , 1989, Nature.

[38]  H. Barlow,et al.  Evidence for a Physiological Explanation of the Waterfall Phenomenon and Figural After-effects , 1963, Nature.

[39]  S. McKee,et al.  Precise velocity discrimination despite random variations in temporal frequency and contrast , 1986, Vision Research.

[40]  J. Pokorny.  Foundations of Cyclopean Perception , 1972 .

[41]  Christopher W. Tyler,et al.  Spatio-temporal properties of Panum's fusional area , 1981, Vision Research.

[42]  P. Cavanagh,et al.  Motion: the long and short of it. , 1989, Spatial vision.

[43]  S. Anstis.  The perception of apparent movement. , 1980, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[44]  B JULESZ,et al.  Binocular Depth Perception without Familiarity Cues , 1964, Science.

[45]  K. Nakayama,et al.  Psychophysical isolation of movement sensitivity by removal of familiar position cues , 1981, Vision Research.

[46]  H R Wilson,et al.  A model for motion coherence and transparency , 1994, Visual Neuroscience.

[47]  J. Lewis,et al.  Probit Analysis (3rd ed). , 1972 .

[48]  Christopher Bowd,et al.  Properties of the stereoscopic (Cyclopean) motion aftereffect , 1994, Vision Research.

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