The railroad tracks stretch straight and far away from me over the desert and on to the horizon. I stand squarely between them, looking along them to the horizon, and I observe both that they converge as distance gets greater and also that they are at every distance equidistant. This is the perceptual paradox of converging parallels. Every one has the experience, and Blumenfeld (1, pp. 323-346)...

The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angl...

Binocular disparity, the differential angular separation between pairs of image points in the two eyes, is the well-recognized basis for binocular distance perception. Without denying disparity's role in perceiving depth, we describe two perceptual phenomena, which indicate that a wider view of binocular vision is warranted. First, we show that disparity can play a critical role in two-dimensio...

This paper presents a novel framework for training models to recognise simple spatial-motion events, such as those described by the verbs pick up, put down, push, pull, drop, tip, and tap and classifying novel observations into previously trained classes. Simple colourand motionbased segmentation and tracking techniques are used to produce a time series of feature vectors constructed from the 2...

In a metrical space, there exists an intimate relation between collinearity and parallelity. In particular, in a Riemannian space collinearity is just a special case of parallelity. Is this true for visual space as well? We investigated the visual perception of collinearity by having subjects align two bars in the horizontal plane at eye height. The distances of the bars from the subject and th...

Visual perceptual disorders are often presented as a disparate group of neurological deficits with little consideration given to the wide range of visual symptoms found in psychiatric and neurodevelopmental disease. Here, the authors attempt a functional anatomical classification of all disorders linked to visual perception, whatever the clinical context in which they arise, including those dis...

The primate visual motion system performs numerous functions essential for survival in a dynamic visual world. Prominent among these functions is the ability to recover and represent the trajectories of objects in a form that facilitates behavioral responses to those movements. The first step toward this goal, which consists of detecting the displacement of retinal image features, has been stud...