Psychophysical Evidence of a Sustained Input to Directionally Selective Motion Mechanisms

Human psychophysical evidence congruent with neurophysiological findings of a sustained input to directionally selective motion sensors in cat visual cortex is reported. Apparent motion was produced by displaying a group of dots in two frames (F1 and F2), where F2 was a translated version of F1. All stimulus sequences included a period during which F1 and F2 were displayed concurrently (combined images) and a period during which only F1 or F2 was on display (single images). There were three stimulus sequences: a display beginning with combined and ending with single image, a display beginning with single and ending with combined image, and a display beginning with F1, continuing with combined image, and ending with F2. Six durations of single and of combined images (10, 20, 40, 80, 160, and 320 ms) were crossed factorially in each stimulus sequence. Directional motion was seen easily at long durations of the single image in all stimulus sequences, as would be expected on the basis of a sustained input to the directional-motion-sensing mechanisms. Perception of directional motion improved with the duration of single images, but declined as the duration of combined images was increased. Baker and Cynader's model could account for the effect of duration of single images, but not for the effect of duration of combined images. An elaborated version of the model provides a good qualitative match to all empirical findings.

[1]  G. Sperling.  The description and luminous calibration of cathode ray oscilloscope visual displays , 1971 .

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

[3]  J. van Santen,et al.  Elaborated Reichardt detectors. , 1985, Journal of the Optical Society of America. A, Optics and image science.

[4]  D. G. Albrecht,et al.  Cortical neurons: Isolation of contrast gain control , 1992, Vision Research.

[5]  Walter F. Bischof,et al.  Stimulus-Onset Asynchrony Is Not Necessary for Motion Perception or Metacontrast Masking , 1993 .

[6]  W. Reichardt,et al.  Autocorrelation, a principle for the evaluation of sensory information by the central nervous system , 1961 .

[7]  J. Pola,et al.  Visual persistence: effects of flash luminance, duration and energy. , 1974, Vision research.

[8]  R M BOYNTON,et al.  Visual responses to equally bright stimuli of unequal luminance. , 1962, Journal of the Optical Society of America.

[9]  Gary Finley,et al.  A high-speed point plotter for vision research , 1985, Vision Research.

[10]  F. Campbell,et al.  The influence of spatial frequency and contrast on the perception of moving patterns , 1981, Vision Research.

[11]  C W Eriksen,et al.  Some temporal characteristics of visual pattern perception. , 1967, Journal of experimental psychology.

[12]  C. Baker,et al.  A sustained input to the direction-selective mechanism in cat striate cortex neurons , 1994, Visual Neuroscience.

[13]  Alan J. Happ,et al.  Visual Motion Processing And Display Design , 1987 .

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

[15]  W. Levick,et al.  Responses of cat retinal ganglion cells to brief flashes of light , 1970, The Journal of physiology.

[16]  O J Braddick,et al.  Temporal Properties of the Short-Range Process in Apparent Motion , 1985, Perception.

[17]  V. Lollo,et al.  Equating the brightness of brief visual stimuli of unequal durations , 1986 .

[18]  D. Heeger.  Normalization of cell responses in cat striate cortex , 1992, Visual Neuroscience.

[19]  Allan Pantle,et al.  An energy model of interframe interval effects in single-step apparent motion , 1994, Vision Research.

[20]  Y. Galifret,et al.  A psychophysical study of the visual perception of “instantaneous” and “durable” , 1977, Vision Research.

[21]  T. W. Butler.  Luminance-duration relationships in the photopic ERG and the apparent brightness of flashes , 1975, Vision Research.

[22]  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.

[23]  H. K. Hartline,et al.  Intensity and duration in the excitation of single photoreceptor units , 1934 .