Elsevier

Vision Research

Volume 29, Issue 11, 1989, Pages 1621-1630
Vision Research

The combination of motion signals over time

https://doi.org/10.1016/0042-6989(89)90143-0Get rights and content

Abstract

The improvement in performance with increasing number of frames in a random-dot kinematogram (temporal recruitment) was assessed by measuring threshold signal-to-noise ratios for direction discrimination. At fast frame presentation rates (50 Hz) thresholds fell sharply as the number of frames in the sequence increased, whereas at slow frame presentation rates (20 and 10 Hz) there was a less dramatic fall in thresholds. The similarity between the results at 20 and 10 Hz suggests that the mechanism of this less dramatic rise is relatively independent of temporal factors. The recruitment effect also does not appear to be limited by a maximum spatial range. We propose that temporal recruitment may occur via two mechanisms. One involves stimulating motion detectors with greater spans and delays, whilst the other involves the co-operative interaction of signals from units tuned to similar directions and having similar spans and delays. This distinction is supported by a further experiment which eliminates the first of these recruitment mechanisms by destroying possible correlations between non-adjacent frames.

References (37)

  • C.L. Baker et al.

    Temporal properties of the short-range process in apparent motion

    Perception

    (1985)
  • H.B. Barlow et al.

    The mechanism of directionally selective units in rabbit's retina

    Journal of Physiology, London

    (1965)
  • O.J. Braddick

    Low-level and high-level processes in apparent motion

    Philosophical Transactions of the Royal Society, London

    (1980)
  • D.C. Burr et al.

    Intra-cortical inhibition prevents simple cells from responding to textured visual patterns

    Experimental Brain Research

    (1981)
  • J.J. Chang et al.

    Cooperative phenomena in apparent motion perception of random-dot cinematograms

    Vision Research

    (1984)
  • P.G.H. Clark

    Subjective standstill caused by interaction of moving patterns

    Vision Research

    (1977)
  • B. De Bruyn et al.

    Human velocity and direction discrimination measured random dot patterns

    Vision Research

    (1988)
  • J.J. Koenderink et al.

    Spatial and temporal parameters of motion detection in the peripheral visual field

    Journal of the Optical Society of America

    (1985)
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    Present address: Department of Brain and Cognitive Sciences, E25-236, Massachusetts Institute of Technology, MA 02139, U.S.A.

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