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The visual system completes image fragments into larger regions when those fragments are taken to be the visible portions of an occluded object. Kellman and Shipley (1991) argued that this "amodal" completion is based on the way that the contours of image fragments "relate." Contours relate when their imaginary extensions intersect at an obtuse or right(More)
The perceived direction of apparent motion can be influenced by both "top-down" factors, such as expectation, and by "bottom-up" or stimulus-driven factors, such as grouping (Tse, P., Cavanagh, P. & Nakayama, K. (1998). The role of parsing in high-level motion processing. In T. Watanabe, High-level motion processing - computational, neurobiological and(More)
A new motion illusion, "illusory rebound motion" (IRM), is described. IRM is qualitatively similar to illusory line motion (ILM). ILM occurs when a bar is presented shortly after an initial stimulus such that the bar appears to move continuously away from the initial stimulus. IRM occurs when a second bar of a different color is presented at the same(More)
When image fragments are taken to correspond to the visible portions of a single occluded object, the object is said to 'amodally complete' behind the occluder. Kellman and Shipley (Kellman, P. J., & Shipley, T. F. (1991). A theory of visual interpolation in objective perception. Cognitive Psychology, 23, 144-221) argued that when the virtual contour(More)
UNLABELLED Unlike the motion of a continuous contour, the motion of a single dot is unambiguous and immune to the aperture problem. Here we exploit this fact to explore the conditions under which unambiguous local motion signals are used to drive global percepts of an ellipse undergoing rotation. In previous work, we have shown that a thin, high aspect(More)
After prolonged viewing of a slowly drifting or rotating pattern under strict fixation, the pattern appears to slow down and then momentarily stop. The authors show that grouping can slow down the process of "motion fading," suggesting that cortical configural form analysis interacts with the computation of motion signals during motion fading. The authors(More)
Recent work shows that abrupt onsets reflexively capture attention and trigger saccades that compete with voluntary saccades. To test whether oculomotor capture occurs when no saccade is being planned, we measured fixational eye movements in the absence or presence of an abrupt onset at peripheral locations. We found no effect of abrupt onset location on(More)
The perceived angular velocity of an ellipse undergoing a constant rate of rotation will vary as its aspect ratio is changed. Specifically, a "fat" ellipse with a low aspect ratio will in general be perceived to rotate more slowly than a "thin" ellipse with a higher aspect ratio. Here we investigate this illusory underestimation of angular velocity in the(More)
We report a new visual illusion, where a global shape appears to continually move away from fixation, even though it remains a fixed distance from fixation. The illusion occurs because local motion signals within the object indicate motion away from fixation, and are incorrectly attributed by the visual system to the motion trajectory of the global object.(More)