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Spatial interactions are extensive in the peripheral visual field, extending up to about half the retinal eccentricity of the target (Toet and Levi, Vision Res. 32, 1349-1357, 1992). In the present study it is shown that the degree and extent of peripheral spatial interaction depends in large measure on the similarity between test and flanking stimuli. The(More)
Imperfections in binocular image pairs can cause serious viewing discomfort. For example, in stereo vision systems eye strain is caused by unintentional mismatches between the left and right eye images (stereo imperfections). Head-mounted displays can induce eye strain due to optical misalignments. We have experimentally determined the level of (dis)comfort(More)
The perceived direction of motion of a one-dimensional grating is measured in straight-edged rectangular and indented rectangular apertures. It is shown that the perceived direction of motion of the pattern is largely determined by the directions of motion at the edges, rather than by the aspect ratio or global shape of the aperture. The edge motion vectors(More)
We have studied vernier acuity for patterns in which the stimuli to be aligned either are similar in their spatial and color characteristics or differ in these properties. The question which we address is whether spatial localization is independent of the channels being stimulated by the patterns to be aligned. We found that the precision of vernier(More)
The effect of several new stimulus parameters on the perception of a moving plaid pattern (the sum of two sine-wave gratings) were tested. It was found that: (i) the degree of perceived sliding is strongly influenced by the aperture configuration through which the plaid is viewed; (ii) the chromaticity of the sinusoidal components affects coherence in that(More)
When a target object embedded in an array of other objects can be distinguished along a single feature dimension (e.g. color or shape), it can be detected in parallel. When a target object is defined by a conjunction of stimulus features, at least some serial search is required, indicating that the visual system is less efficient in conducting a parallel(More)
Background: About 30% of the population has difficulties detecting the sign and the magnitude of binocular disparity in the absence of eye movements, a phenomenon called stereo-anomaly. The stereo-anomaly tests so far are based on disparity only (e.g. red–green stereograms), which means that other depth cues cannot be used and even provide conflicting depth(More)
We have examined the human ability to determine the direction of movement of a variety of plaid patterns. The plaids were composed of two orthogonal sine-wave gratings. When the plaid components are of unequal spatial frequency or sometimes of unequal contrast, observers judge the direction of movement incorrectly. In terms of the two-stage model of Adelson(More)
  • F L Kooi
  • Journal of the Optical Society of America. A…
  • 1995
When regions containing a counterphasing sine-wave grating are presented side by side and in spatial and temporal quadrature phase, a transparent perception of motion results. This occurs even though none of the stimulus parts is moving. The two percepts of motion in these displays are in opposite directions, one analogous to brightness contrast, the other(More)
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