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Visual mechanisms in primary visual cortex are suppressed by the superposition of gratings perpendicular to their preferred orientations. A clear picture of this process is needed to (i) inform functional architecture of image-processing models, (ii) identify the pathways available to support binocular rivalry, and (iii) generally advance our understanding(More)
In experiments that measure a point of subjective equality, it is necessary to employ a psychophysical technique that measures the 50% point (P50) on the psychometric function. The standard staircase is an attractive candidate, because its simplicity makes it easy to understand and implement. However, Pentland (1980, Perception & Psychophysics, 28, 377-379)(More)
Above threshold, two superimposed sinusoidal gratings of the same spatial frequency (eg 1 cycle deg-1), of equal moderate contrast (eg C1 = C2 = 6%), and with orientations of +/- 45 degrees, usually look like a compound structure containing vertical and horizontal edges (ie a blurred checkerboard). These feature orientations are very different from the(More)
We recorded MEG responses from 17 participants viewing random-dot patterns simulating global optic flow components (expansion, contraction, rotation, deformation, and translation) and a random motion control condition. Theta-band (3-7 Hz), MEG signal power was greater for expansion than the other optic flow components in a region concentrated along the(More)
– The MBARI Ocean Observing System (MOOS) will consist of networked observation platforms and sensors deployed over a wide geographic area, distributed throughout the oceanic water column. The network will utilize a variety of communication links, including optical fiber, microwave, packet radio, satellite, and acoustic, resulting in diversity of(More)
Over the last decade, television screens and display monitors have increased in size considerably, but has this improved our televisual experience? Our working hypothesis was that the audiences adopt a general strategy that "bigger is better." However, as our visual perceptions do not tap directly into basic retinal image properties such as retinal image(More)
Much evidence shows that early vision employs an array of spatial filters tuned for different spatial frequencies and orientations. We suggest that for moderately low spatial frequencies these preliminary filters are not treated independently, but are used to perform grouping and segmentation in the patchwise Fourier domain. For example, consider a(More)
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