Binocular neurons that are closely related to depth perception should respond selectively for stimuli eliciting an appropriate depth sensation. To separate perceived depth from local disparity within the receptive field, sinusoidal luminance gratings were presented within a circular aperture. The disparity of the aperture was coupled to that of the grating, thereby rendering unambiguous the psy...

Recent research on perceptual grouping is described with particular emphasis on identifying the level(s) at which grouping factors operate. Contrary to the classical view of grouping as an early, two-dimensional, image-based process, recent experimental results show that it is strongly influenced by phenomena related to perceptual constancy, such as binocular depth perception, lightness constan...

We consider the problem of permutation reconstruction, which is a variant of graph reconstruction. Given a permutation p of length n, we delete k of its entries in each possible way to obtain (n k ) subsequences. We renumber the sequences from 1 to n−k preserving the relative size of the elements to form (n−k)-minors. These minors form a multiset Mk(p) with an underlying set M ′ k(p). We study ...

We investigate the underlying reasons for producers’ choice of marketing channels for stocker cattle in the United States. In addition to traditional public auctions, private sales, video auctions, and Internet auctions have been recently used in the marketing of stocker cattle. We find that while the number of marketing options may have increased in recent years, only relatively large producer...

It is well known that chromatic information can assist in solving the stereo correspondence problem. It has also been suggested that there are two independent first-order stereopsis mechanisms, one sensitive to chromatic contrast and the other sensitive to luminance contrast (Vision Research 37 (1997) 1271). Could the effect of chromatic information on stereo correspondence be subserved by inte...

Horizontal fusional responses of 11 strabismics, with normal or anomalous retinal correspondence, were studied. These included four small-angle esotropes with amblyopia, one intermittent esotrope (overcorrected intermittent exotrope), two intermittent exotropes (preoperative esotropes), one accommodative esotrope, and three microtropes with amblyopia. Fusional stimuli (with a constant accommoda...

To survive, animals must be able to react appropriately (in temporal and behavioral terms) when facing a threat. One of the essential parameters considered by the defensive system is the distance of the threat, the "defensive distance." In this study, we investigate the visual depth cues that could be considered as an alarm cue for the activation of the defensive system. For this purpose, we pe...

Architectural design is often mediated on two-dimensional representation systems and envisioned three-dimensionally in the pictorial space. The developments of advanced digital technologies have enabled us to create the pictorial representations of un-built design projects that can appear as real as photographs. The visually appealing pictures produced by photorealistic rendering tools are usef...

This paper describes an experiment where the effect of dynamic shadows in an immersive virtual environment is measured with respect to spatial perception and presence. Eight subjects were given tasks to do in a virtual environment. Each subject carried out five experimental trials, and the extent of dynamic shadow phenomena varied between the trials. Two measurements of presence were used a sub...

This thesis investigates the use of sound to improve user depth perception in 3D computer interfaces. Two experiments were performed to determine a) the effect that sound has on depth perception and b) how this effect varies over an extended period of use. When compared to a “no sound” environment with limited visual depth cues, sound feedback helped to reduce task errors while at the same time...