Stereoscopic distance perception

Limited cue, open-loop tasks in which a human observer indicates distances or relations among distances are discussed. By open-loop tasks, it is meant tasks in which the observer gets no feedback as to the accuracy of the responses. What happens when cues are added and when the loop is closed are considered. The implications of this research for the effectiveness of visual displays is discussed. Errors in visual distance tasks do not necessarily mean that the percept is in error. The error could arise in transformations that intervene between the percept and the response. It is argued that the percept is in error. It is also argued that there exist post-perceptual transformations that may contribute to the error or be modified by feedback to correct for the error

Auditory environmental context affects visual distance perception

In this article, we show that visual distance perception (VDP) is influenced by the auditory environmental context through reverberation-related cues. We performed two VDP experiments in two dark rooms with extremely different reverberation times: an anechoic chamber and a reverberant room. Subjects assigned to the reverberant room perceived the targets farther than subjects assigned to the anechoic chamber. Also, we found a positive correlation between the maximum perceived distance and the auditorily perceived room size. We next performed a second experiment in which the same subjects of Experiment 1 were interchanged between rooms. We found that subjects preserved the responses from the previous experiment provided they were compatible with the present perception of the environment; if not, perceived distance was biased towards the auditorily perceived boundaries of the room. Results of both experiments show that the auditory environment can influence VDP, presumably through reverberation cues related to the perception of room size.Fil: Etchemendy, Pablo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Abregú, Ezequiel Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Calcagno, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Eguia, Manuel Camilo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Vechiatti, Nilda. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Iasi, Federico. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Vergara, Ramiro Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; Argentin

Learning and Exposure Affect Environmental Perception Less than Evolutionary Navigation Costs

Russell E. Jackson is with University of Idaho, Chéla R. Willey is with University of California Los Angeles, Lawrence K. Cormack is with UT Austin.Most behaviors are conditional upon successful navigation of the environment, which depends upon distance perception learned over repeated trials. Unfortunately, we understand little about how learning affects distance perception–especially in the most common human navigational scenario, that of adult navigation in familiar environments. Further, dominant theories predict mutually exclusive effects of learning on distance perception, especially when the risks or costs of navigation differ. We tested these competing predictions in four experiments in which we also presented evolutionarily relevant navigation costs. Methods included within- and between-subjects comparisons and longitudinal designs in laboratory and real-world settings. Data suggested that adult distance estimation rapidly reflects evolutionarily relevant navigation costs and repeated exposure does little to change this. Human distance perception may have evolved to reflect navigation costs quickly and reliably in order to provide a stable signal to other behaviors and with little regard for objective accuracy.Psycholog

Effects of virtual acoustics on dynamic auditory distance perception

Sound propagation encompasses various acoustic phenomena including reverberation. Current virtual acoustic methods, ranging from parametric filters to physically-accurate solvers, can simulate reverberation with varying degrees of fidelity. We investigate the effects of reverberant sounds generated using different propagation algorithms on acoustic distance perception, i.e., how faraway humans perceive a sound source. In particular, we evaluate two classes of methods for real-time sound propagation in dynamic scenes based on parametric filters and ray tracing. Our study shows that the more accurate method shows less distance compression as compared to the approximate, filter-based method. This suggests that accurate reverberation in VR results in a better reproduction of acoustic distances. We also quantify the levels of distance compression introduced by different propagation methods in a virtual environment.Comment: 8 Pages, 7 figure

Distance Perception in Virtual Reality

Distance perception in virtual reality is radically different than distance perception in the real world. For example, distances tend to be underperceived in virtual reality, and anisotropic effects of distance perception seen in the real world are exacerbated. Three experiments were conducted examining distance perception in virtual reality. The first two experiments examined the speed of improvement as a result of interaction and the transfer of improvement across different scales of space. The third experiment examined the anisotropic effect of distance orientation on perceived distance within the virtual environment. The first experiment found that five interaction trials resulted in a large improvement in perceived distance, and subsequent interactions also continued improvement, but suffered heavily from diminishing returns. In the second experiment, interaction with near (1-2m) objects improved distance perception for near but not far (4-5m) objects, while interaction with far objects improved distance perception for both near and far objects. In the third experiment, the orientation of the distances between the objects significantly affected distance perception between all but two of the conditions. These results help generate strategies to reduce underperception in virtual reality, and help distinguish between theories of how interacting with environments influences perceived distances

Auditory environmental context affects visual distance perception

To perceive the distance to an object through the visual modality, an observer uses a variety of cues, many of which may not be directly related to the target. This is illustrated by the fact that in a well-lit environment (with multiple visual cues) visual distance perception (VDP) is relatively accurate, whereas in a dark environment (where the observer can only see the target) VDP be- comes inaccurate. Besides, a number of recent studies indicate that VDP is not only affected by the availability and reliability of depth cues, but also can be influenced by the context even in the presence of multiple visual cues. Here we provide evidence that VDP is influenced by the auditory environmental context through reverberation-related cues. We conducted VDP experi- ments in two dark rooms with extremely different reverberation times: an anechoic chamber and a reverberant room. We first show that the distance to a visual object located in the reverberant chamber was perceived significantly farther than the same target located at the same distance in the anechoic chamber. The results also show that the maximum distance perceived by partic- ipants correlated significantly with the perceived size of the room. In addition, participants who performed the experiment in the reverberant room reported a perceived size greater than those who performed the experiment in the anechoic chamber although both rooms are of similar sizes. Secondly we note that by separating participants between musicians and non-musicians only the former group perceived differences in the size of the room through auditory modality; moreover, only this group perceived the distance to the visual object in the reverberant chamber farther than in the anechoic chamber. On the other hand, the group of non-musicians did not perceive dif- ferences in the size of both rooms or in the perceived distance in both chambers. These results show that the auditory environment can influence the VDP, presumably by reverberation cues related to auditory perception of the size of a room

How Haptic Size Sensations Improve Distance Perception

Determining distances to objects is one of the most ubiquitous perceptual tasks in everyday life. Nevertheless, it is challenging because the information from a single image confounds object size and distance. Though our brains frequently judge distances accurately, the underlying computations employed by the brain are not well understood. Our work illuminates these computions by formulating a family of probabilistic models that encompass a variety of distinct hypotheses about distance and size perception. We compare these models' predictions to a set of human distance judgments in an interception experiment and use Bayesian analysis tools to quantitatively select the best hypothesis on the basis of its explanatory power and robustness over experimental data. The central question is: whether, and how, human distance perception incorporates size cues to improve accuracy. Our conclusions are: 1) humans incorporate haptic object size sensations for distance perception, 2) the incorporation of haptic sensations is suboptimal given their reliability, 3) humans use environmentally accurate size and distance priors, 4) distance judgments are produced by perceptual “posterior sampling”. In addition, we compared our model's estimated sensory and motor noise parameters with previously reported measurements in the perceptual literature and found good correspondence between them. Taken together, these results represent a major step forward in establishing the computational underpinnings of human distance perception and the role of size information.National Institutes of Health (U.S.) (NIH grant R01EY015261)University of Minnesota (UMN Graduate School Fellowship)National Science Foundation (U.S.) (Graduate Research Fellowship)University of Minnesota (UMN Doctoral Dissertation Fellowship)National Institutes of Health (U.S.) (NIH NRSA grant F32EY019228-02)Ruth L. Kirschstein National Research Service Awar

The Effects of Stress on Distance Perception

Although there has been a great deal of research on binocular distance perception (Foley, 1980; Gogel, 1977), a number of questions remain unexplored. One such question involves how our ability to perceive distances is influenced by fitness and stress (internal and external). Previous research has shown that kinesthetic stress (via backpack weight) influences a person’s ability to accurately guess distances (Proffitt, Bhalla, Gossweiler, & Midgett, 2003). This research did not only attempt to replicate previous work, but also extend it by exploring potential interactions between fitness level and mental stress on distance perception, a combination that is often encountered by soldiers, firefighters, and rescue workers. Mental stress was measured using the State Anxiety Inventory test (Spielberger, Reheiser, & Sydeman, 1995) and cardiovascular fitness was measured using MET scores (Jurca et al., 2005). Physical stress was manipulated by asking participants to estimate distances and then walk blindly to the target while carrying a backpack weighing 20% of their weight. We were unable to replicate Proffitt. We did however find a positive correlation between cardiovascular fitness and error in the second block of the blind walking task for the heavy backpack condition, r(22) = -.45, p = 0.03