Flash lag in depth

The perceived position of a moving target at a particular point in time, indicated by a flash, is often judged to be different from its actual location. Here, we show that the position of a target moving in depth is also systematically mislocalized. We used three types of targets moving in depth at a range of speeds from 2 to 16 cm/s. (i) A target realistically rendered that included concordant looming, disparity, and perspective cues. (ii) A random dot surface whose depth was defined by disparity, without concordant perspective or looming cues. (iii) A surface of dynamic random dots whose depth was defined by disparity with no consistent motion visible monocularly. Subjects viewed the targets moving either towards or away from them and indicated whether the targets appeared to be nearer or farther than a continuously present reference depth at the moment that a flash was presented. A staircase procedure was used to null, and thus measure, any perceptual displacement from the reference depth. A flash lag in depth was found in which the target appeared ahead of its true position, displaced by a constant amount of time depending on the stimulus type and the direction of motion (towards or away). The time displacement varied from 76 ms (for the realistic target moving away from the observer) to 263 ms (for static random dots moving towards). These effects may depend on the confidence with which subjects were able to judge the location of our various targets: greater confidence leading to a smaller temporal displacement.

[1]  M. Landy,et al.  Measurement and modeling of depth cue combination: in defense of weak fusion , 1995, Vision Research.

[2]  Melvyn A. Goodale,et al.  The role of image size and retinal motion in the computation of absolute distance by the Mongolian gerbil (Meriones unguiculatus) , 1990, Vision Research.

[3]  W. Metzger,et al.  Versuch einer gemeinsamen Theorie der Phänomene Fröhlichs und Hazelhoffs und Kritik ihrer Verfahren zur Messung der Empfindungszeit , 1932 .

[4]  D. Regan,et al.  Separable aftereffects of changing-size and motion-in-depth: Different neural mechanisms? , 1979, Vision Research.

[5]  D Regan,et al.  Just-noticeable difference in the speed of cyclopean motion in depth and the speed of cyclopean motion within a frontoparallel plane. , 1997, Journal of experimental psychology. Human perception and performance.

[6]  David R Badcock,et al.  Asymmetries in the Sensitivity to Motion in Depth: A Centripetal Bias , 1993, Perception.

[7]  David Alais,et al.  Neural latencies do not explain the auditory and audio-visual flash-lag effect , 2005, Vision Research.

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

[9]  Julie M. Harris,et al.  Minimum displacement thresholds for binocular three-dimensional motion , 2002, Vision Research.

[10]  D. Mackay Perceptual Stability of a Stroboscopically Lit Visual Field containing Self-Luminous Objects , 1958, Nature.

[11]  Julie M. Harris,et al.  Poor Speed Discrimination Suggests that there is No Specialized Speed Mechanism for Cyclopean Motion , 1996, Vision Research.

[12]  P. Cavanagh,et al.  Illusory spatial offset of a flash relative to a moving stimulus is caused by differential latencies for moving and flashed stimuli , 2000, Vision Research.

[13]  T J Sejnowski,et al.  Motion integration and postdiction in visual awareness. , 2000, Science.

[14]  E. Brenner,et al.  Motion extrapolation is not responsible for the flash–lag effect , 2000, Vision Research.

[15]  C W Tyler,et al.  Stereoscopic Depth Movement: Two Eyes Less Sensitive than One , 1971, Science.

[16]  M. Lappe,et al.  Neuronal latencies and the position of moving objects , 2001, Trends in Neurosciences.

[17]  Ryota Kanai,et al.  Stopping the motion and sleuthing the flash-lag effect: spatial uncertainty is the key to perceptual mislocalization , 2004, Vision Research.

[18]  Zheng Tang,et al.  3D flash lag illusion , 2004, Vision Research.

[19]  K. Tanaka,et al.  Underlying mechanisms of the response specificity of expansion/contraction and rotation cells in the dorsal part of the medial superior temporal area of the macaque monkey. , 1989, Journal of neurophysiology.

[20]  Romi Nijhawan,et al.  Motion extrapolation in catching , 1994, Nature.

[21]  D Regan,et al.  The dissociation of sideways movements from movements in depth: psychophysics. , 1973, Vision research.

[22]  I. Murakami,et al.  Latency difference, not spatial extrapolation , 1998, Nature Neuroscience.

[23]  T. N. Thomas,et al.  Serotonin uptake and release by subcellular fractions of bovine retina , 1980, Vision Research.

[24]  S. Klein,et al.  Evidence for an Attentional Component of the Perceptual Misalignment between Moving and Flashing Stimuli , 2002, Perception.

[25]  K. Tanaka,et al.  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. , 1989, Journal of neurophysiology.

[26]  J. Namba,et al.  The attentional modulation of the flash-lag effect. , 2002, Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas.

[27]  Robert A. Jacobs,et al.  Modeling the Combination of Motion, Stereo, and Vergence Angle Cues to Visual Depth , 1999, Neural Computation.

[28]  Harold E Bedell,et al.  Differential latencies and the dynamics of the position computation process for moving targets, assessed with the flash-lag effect , 2004, Vision Research.

[29]  D. Regan,et al.  Just-noticeable difference in the speed of cyclopean motion in depth and the speed of cyclopean motion within a frontoparallel plane. , 1997, Journal of experimental psychology. Human perception and performance.

[30]  Shinsuke Shimojo,et al.  Changing objects lead briefly flashed ones , 2000, Nature Neuroscience.

[31]  B. G. Cumming,et al.  Binocular mechanisms for detecting motion-in-depth , 1994, Vision Research.

[32]  R. S Allison,et al.  Stereopsis with persisting and dynamic textures , 2000, Vision Research.

[33]  M. Ernst,et al.  Humans integrate visual and haptic information in a statistically optimal fashion , 2002, Nature.

[34]  R. S Allison,et al.  Temporal dependencies in resolving monocular and binocular cue conflict in slant perception , 2000, Vision Research.

[35]  Y Dan,et al.  Motion-Induced Perceptual Extrapolation of Blurred Visual Targets , 2001, The Journal of Neuroscience.

[36]  D Regan,et al.  Human ocular vergence movements induced by changing size and disparity. , 1986, The Journal of physiology.