Visual orientation by motion-produced blur patterns: Detection of divergence

Harrington, Thomas L.; Harrington, Marcia K.; Wilkins, Clive; Koh, Y. O.

doi:10.3758/bf03204388

Cited by 12 publications

(7 citation statements)

References 45 publications

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“…They hypothesized that the arc was interpreted by the visual system as motion blur. More recently, Geisler (1999) hypothesized that oriented cells in visual cortex may respond to motion streaks and that these responses may code motion parallel to a cell's orientation (see also Harrington, Harrington, Wilkins and Koh;. However, these approaches will require modification if they are to account for our results.…”

Section: Discussionmentioning

confidence: 69%

Perceived motion in complementary afterimages: verification of a neural network theory

Francis

2000

Spatial Vis

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Steady fixation of a regular pattern like a bar grating or concentric circles leads to a complementary afterimage at pattern offset. The afterimage has the appearance of shimmering lines that are locally orthogonal to the orientations of the inducing image. Additionally, the afterimage includes motion running parallel to the orientation of the afterimage lines. We argue that this afterimage motion supports the existence of a cue to motion that is based on the spatial organization of oriented responses. This cue was previously proposed after analysis of a neural network model of visual perception. We test predictions of the model on various types of complementary afterimage inducing stimuli. When a contrast or size gradient is included in the inducing image, the afterimage motion moves toward the higher part of the gradient, in agreement with the model. Implications of this cue for computational and neurophysiological theories of motion perception are discussed.

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Section: Discussionmentioning

confidence: 69%

Perceived motion in complementary afterimages: verification of a neural network theory

Francis

2000

Spatial Vis

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“…The faster displays may have produced a blur pattern that was useful in registering the gradient (Harrington, Harrington, Wilkins, & Koh, 1980). The speeds studied, however, are not usually associated with blur.…”

Section: Resultsmentioning

confidence: 99%

Velocity gradients and relative depth perception

Braunstein

Andersen

1981

Perception & Psychophysics

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The effectiveness of velocity gradients in providing relative depth information was assessed using random dot patterns translating horizontally. The gradients simulated two planes meeting at a horizontal line at the center, and subjects judged whether the center was the nearest or farthest part of the display. Accuracy increased with maximum dot speed, exceeding 90% in conditions combining the highest speed (lOA°/see) and longer of two display durations (10 sec) with unrestricted fixation. Separate experiments examined a rotational component perceived in the motion of the planes and the latency in reporting a rigid organization of the displays. Possible reasons for the chance accuracy found by Farber and McConkie (1979) and alternative explanations of the effect of maximum dot speed on accuracy are discussed. A model is presented that accounts for the effects of dot speed and display duration on the accuracy of relative depth judgments.The velocities with which the projections of objects move across the retina have long been regarded as providing information about the relative distances of objects from the observer (Helmholtz, 1925). Gibson (1950) has proposed that a gradient of velocities is important in surface perception. Gibson, Gibson, Smith, and Flock (1959) compared displays of two velocities with displays of velocity gradients. The texture elements were reported to vary in distance in both cases, but only in the gradient case were the faster elements consistently reported to be closer. That study used a shadow projection technique that produced a texture gradient corresponding to the velocity gradient, leaving unanswered the question of whether relative depth can be perceived on the basis of a velocity gradient alone. Braunstein (1968) used computer-generated displays to separate texture and velocity gradient information. Velocity information clearly dominated texture information in determining judged slant, but the question of whether reversals in relative depth (i.e., the slower elements perceived as closer) could occur with slant information available only from the velocity gradient was not addressed directly.Two recent studies used displays of velocity gradients carried by texture elements that were randomly and uniformly distributed across the field of view. Rogers and Graham (1979) studied velocity gradients representing slanted and corrugated three-dimensional surfaces. The translation of the dot patterns across a display monitor in one condition was linked to the subject's head movements relative to a stationary monitor and in another condition was linked to moveThis research was supported, in part, by National Science Foundation Grant BNS-76-81499. The authors are grateful to Jerry Keys, who developed the computer programs for generating the stimuli. ment of the monitor relative to the subject's stationary head. Subjects were able to identify the threedimensional shape and to judge the relative depth of portions of the surface with a high degree of accuracy. Rogers and Graham concluded that, und...

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“…A number of formal analyses of optical flow have appeared since Gibson's (1947Gibson's ( , 1950 original discoveries (Gibson, Olum, & Rosenblatt, 1955;Gordon, 1965;Hadani, Ishai, & Gur, 1980;Harrington, Harrington, Wilkins, & Koh, 1980;Koenderink, 1986;Koenderink & van Doom, 1975, 1976 This research was carried out under Grant AG05223 from the National Institutes of Health.…”

Section: Perception Of Translational Heading From Optical Flowmentioning

confidence: 99%

Perception of translational heading from optical flow.

Warren¹,

Morris²,

Kalish³

1988

Journal of Experimental Psychology: Human Perception and Perfor

376

280

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Radial patterns of optical flow produced by observer translation could be used to perceive the direction of self-movement during locomotion, and a number of formal analyses of such patterns have recently appeared. However, there is comparatively little empirical research on the perception of heading from optical flow, and what data there are indicate surprisingly poor performance, with heading errors on the order of 5 degrees-10 degrees. We examined heading judgments during translation parallel, perpendicular, and at oblique angles to a random-dot plane, varying observer speed and dot density. Using a discrimination task, we found that heading accuracy improved by an order of magnitude, with 75%-correct thresholds of 0.66 degrees in the highest speed and density condition and 1.2 degrees generally. Performance remained high with displays of 63-10 dots, but it dropped significantly with only 2 dots; there was no consistent speed effect and no effect of angle of approach to the surface. The results are inconsistent with theories based on the local focus of outflow, local motion parallax, multiple fixations, differential motion parallax, and the local maximum of divergence. But they are consistent with Gibson's (1950) original global radial outflow hypothesis for perception of heading during translation.

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Visual orientation by motion-produced blur patterns: Detection of divergence

Cited by 12 publications

References 45 publications

Perceived motion in complementary afterimages: verification of a neural network theory

Perceived motion in complementary afterimages: verification of a neural network theory

Velocity gradients and relative depth perception

Perception of translational heading from optical flow.

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