The effect of ingested alcohol on fusion latency at various viewing distances

Although diplopia is a frequently reported symptom of severe alcohol intoxication, there have been few past attempts to describe in any systematic fashion the specific impact of alcohol on fusion. In the present experiment, fusion latency was assessed for 8 male emmetropes. At the beginning of the alcohol condition, they consumed a drink containing 1.4 mllkg of 95% ethanol, plus diluent. For the placebo condition, the drink consisted only of diluent. In each condition, fusion latency (the time required to fuse a binocularly visible target) was recorded for targets requiring a magnitude of vergence that varied from +10 through ?2 meter angles, in 1-meterangle steps. It was found that the far point offusion approached the observer as a direct function of intoxication level. Furthermore, fusion latency increased for optically far and near targets as a systematic function of intoxication, with no effect of alcohol on intermediate targets. The results were consistent with previous findings of alcohol-induced narrowing of vergence range, suggesting that alcohol causes the farthest and nearest distances at which fusion latency is affected to approach an intermediate value. Measurable effects on fusion latency were observed with blood alcohol levels as low as 0.05%–0.06%, considerably below the legal limit for operating a motor vehicle in most states.     

Effect of viewing plane on perceived distances in real and virtual environments

Three experiments examined perceived absolute distance in a head-mounted display virtual environment (HMD-VE) and a matched real-world environment, as a function of the type and orientation of the distance viewed. In Experiment 1, participants turned and walked, without vision, a distance to match the viewed interval for both egocentric (viewer-to-target) and exocentric (target-to-target) extents. Egocentric distances were underestimated in the HMD-VE while exocentric distances were estimated similarly across environments. Since egocentric distances were displayed in the depth plane and exocentric distances in the frontal plane, the pattern of results could have been related to the orientation of the distance or to the type of distance. Experiments 2 and 3 tested these alternatives. Participants estimated exocentric distances presented along the depth or frontal plane either by turning and walking (Experiment 2) or by turning and throwing a beanbag to indicate the perceived extent (Experiment 3). For both Experiments 2 and 3, depth intervals were underestimated in the HMD-VE compared to the real world. However, frontal intervals were estimated similarly across environments. The findings suggest anisotropy in HMD-VE distance perception such that distance underestimation in the HMD-VE generalizes to intervals in the depth plane, but not to intervals in the frontal plane. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

The effect of viewing ultra-fit images on college women's body dissatisfaction

Modern ideals of female attractiveness include an extremely toned and fit appearance in addition to extreme thinness. Although viewing thin models has a negative effect on women's body image, research has not tested the effect of exposure to the ultra-fit physique separate from the thin-ideal. This randomized, posttest-only experiment tested the effects of the athletic aspect of the current ideal by exposing 138 undergraduate women to thin and athletic models, normal weight athletic models, or a control condition consisting of neutral objects. The study also tested the moderating effects of thin-ideal and athletic-ideal internalization. Exposure to thin ultra-fit models, but not normal weight ultra-fit models, produced an increase in body dissatisfaction and neither internalization variable moderated this effect. Findings suggest that interventions that focus on the benefits of fitness while challenging the desirability of thinness may offer promising results.     

True three-dimensional displays that allow viewers to dynamically shift accommodation, bringing objects displayed at different viewing distances into and out of focus.

Under natural viewing conditions, viewers do not just passively perceive. Instead, they dynamically scan the visual scene by shifting their eye fixation and focus between objects at different viewing distances. In doing so, the oculomotor processes of accommodation (eye focus) and vergence (angle between lines of sight of two eyes) must be shifted synchronously to place new objects in sharp focus in the center of each retina. Accordingly, nature has reflexively linked accommodation and vergence, such that a change in one process automatically drives a matching change in the other. Conventional stereoscopic displays force viewers to try to decouple these processes, because while they must dynamically vary vergence angle to view objects at different stereoscopic distances, they must keep accommodation at a fixed distance--or else the entire display will slip out of focus. This decoupling generates eye fatigue and compromises image quality when viewing such displays. In an effort to solve this accommodation/vergence mismatch problem, we have built various prototype displays that can vary the focus of objects at different distances in a displayed scene to match vergence and stereoscopic retinal disparity demands and better simulate natural viewing conditions. By adjusting the focus of individual objects in a scene to match their stereoscopic retinal disparity, the cues to ocular accommodation and vergence are brought into agreement. As in natural vision, the viewer brings different objects into focus by shifting accommodation. As the mismatch between accommodation and vergence is decreased, natural viewing conditions are better simulated and eye fatigue should decrease.     

The effect of waitresses' touch on alcohol consumption in dyads.

A total of 96 men and 48 women participated in a study on the effect of touch in the natural setting of public taverns in the United States. Participants in the same-gender (men-men) or mixed-gender dyads were either touched or not touched by waitress confederates. Regardless of dyad type, participants who were touched consumed more alcohol than participants who were not touched. Men in the mixed-gender dyads consumed more alcohol when the women was touched. Same-gender (men-men) dyads aggregately consumed more alcohol than mixed-gender dyads. The results are interpreted in terms of the environmental cues and the dynamics of the group.     

The effect of set size on the latency to name words

The experiment attempted to determine whether or not Ss' verbal reaction time to name words was influenced by the number of possible word stimuli in a set. It was suggested that a discrepancy between the results of previous investigators was an artefact of the manner in which some of the data had been analysed. The results of the experiment indicate that set size does have a small but significant effect on reaction time to this task.     

The emotional and cognitive effect of immersion in film viewing

This brief report presents an experiment testing the effect of immersion on emotional responses and cognitive genre categorisation of film viewers. Immersion of a film presentation was varied by presenting an animated movie either in a 3D-viewing condition (low immersive condition) or in a CAVE condition (high immersive condition, comparable to virtual reality experience). Viewers rated their emotions and categorised the movies into four basic film genres (action, drama, comedy, and non-fiction). Two distinct types of emotion were measured: Fictional World emotions (e.g., sadness) in response to the presented fictional events and Artefact emotions in response to the film as an artefact (e.g., fascination). Results showed that stronger immersion led to more intense emotions but did not influence genre categorisation. In line with expectations, both types of emotional response were intensified by high immersion. The results are explained by suggesting that highly immersive cinema has its impact on a basic dimension of emotion, namely arousal that underlies both types of emotions.     

The effect of refractive error on central and peripheral motion sensitivity at various exposure durations

Pennsylvania State University, University Park, Pennsylvania 16802 The influence of refractive error on movement sensitivity was determined for a range of stimulus durations in the fovea and periphery. At short durations, threshold is determined by a constant displacement of the stimulus. At longer durations, a constant velocity is required. The correction of peripheral refractive error increases movement sensitivity in the displacement (short duration) component, but does not influence sensitivity in the velocity (long duration) component of the motion threshold. Implications concerning the mechanisms underlying motion perception are discussed.