Sex and age modulate the visual perception of distance

An experiment was conducted to evaluate the ability of 28 younger and older adults to visually bisect distances in depth both indoors and outdoors; half of the observers were male and half were female. Observers viewed 15-m and 30-m distance extents in four different environmental settings (two outdoor grassy fields and an indoor hallway and atrium) and were required to adjust the position of a marker to place it at the midpoint of each stimulus distance interval. Overall, the observers’ judgments were more accurate indoors than outdoors. In outdoor environments, many individual observers exhibited perceptual compression of farther distances (e.g., these observers placed the marker closer than the actual physical midpoints of the stimulus distance intervals). There were significant modulatory effects of both age and sex upon the accuracy and precision of the observers’ judgments. The judgments of the male observers were more accurate than those of the female observers and they were less influenced by environmental context. In addition, the accuracies of the younger observers’ judgments were less influenced by context than those of the older observers. With regard to the precision of the observers’ judgments, the older females exhibited much more variability across repeated judgments than the other groups of observers (younger males, younger females, and older males). The results of our study demonstrate that age and sex are important variables that significantly affect the visual perception of distance.     

Field dependence and the role of visual frameworks in the perception of size

The extent to which apparent size is relationally determined has been studied by Rock and Ebenholtz and by Wenderoth, who came to widely differing conclusions as to the magnitude of this phenomenon. In both studies, a large range of individual differences was observed. In the present study, an attempt was made to account for variations in the influence of visual contexts on the perception of size by relating them to the cognitive style dimension of field dependence/independence. In two situations, relativelyfield-dependent observers made size judgments which were influenced by a frame surrounding the target figure, while relatively field-independent observers made size judgments which were influenced by a frame surrounding the target figure, while relatively field-independent observers tended to be less influenced by the frame, making their judgments approximate the retinal size of the target. The results suggest that assessment of the magnitude of the relational determination of apparent size must consider the cognitive style of the observers as well as situational variations.     

The perception of distances and spatial relationships in natural outdoor environments

The ability of observers to perceive distances and spatial relationships in outdoor environments was investigated in two experiments. In experiment 1, the observers adjusted triangular configurations to appear equilateral, while in experiment 2, they adjusted the depth of triangles to match their base width. The results of both experiments revealed that there are large individual differences in how observers perceive distances in outdoor settings. The observers' judgments were greatly affected by the particular task they were asked to perform. The observers who had shown no evidence of perceptual distortions in experiment 1 (with binocular vision) demonstrated large perceptual distortions in experiment 2 when the task was changed to match distances in depth to frontal distances perpendicular to the observers' line of sight. Considered as a whole, the results indicate that there is no single relationship between physical and perceived space that is consistent with observers' judgments of distances in ordinary outdoor contexts.     

The visual perception of distance ratios outdoors

We conducted an experiment to evaluate the ability of 32 younger and older adults to visually perceive distances in an outdoor setting. On any given trial, the observers viewed 2 environmental distances and were required to estimate the distance ratio—the length of the (usually) larger distance relative to that of the shorter. The stimulus distance ratios ranged from 1.0 (the stimulus distances were identical) to 8.0 (1 distance interval was 8.0 times longer than the other). The stimulus distances were presented within a 26 m × 60 m portion of a grassy field. The observers were able to reliably estimate the stimulus distance ratios: The overall Pearson r correlation coefficient relating the judged and actual distance ratios was 0.762. Fifty-eight percent of the variance in the observers’ perceived distance ratios could thus be accounted for by variations in the actual stimulus ratios. About half of the observers significantly underestimated the distance ratios, while the judgments of the remainder were essentially accurate. Significant modulatory effects of sex and age occurred, such that the male observers’ judgments were the most precise, while those of the older males were the most accurate.     

Distance estimation in vista space

Although distance estimation has been extensively studied in the laboratory, our ability to judge large distances in the field is not well researched. We challenge the notion that large distances are uniformly underestimated. We presented different targets to observers at distances ranging from 25 to 500 m to obtain egocentric distance judgments in natural environments. Three experiments showed that observers tend to underestimate distances below 75 m in a large open field, whereas they overestimate farther distances. Both the eye height of the observer and the size of the target also influenced distance estimation. We conclude that the notion of a uniform vista space has to be reconceived.     

Descartes's blind man revisited: bimanual triangulation of distance using static hand-held rods

Analogous to binocular convergence, we tested Descartes's proposal that a blind person could triangulate distances using crossed hand-held rods by sensing hand separation and wrist angles. In Experiment 1, 22 participants judged distances to loci at 4 distances, 18-36 in. (45.7-91.4 cm), at 5 eccentricities, 0-12 in. (0-30.5 cm) left and right of center. Participants reliably differentiated and scaled distances. The median individual multiple correlation (actual distances and eccentricities vs. judged distances; nonlinear with eccentricity) was .91 (range, .75 to .95; group R = .98). In Experiment 2, 2 experienced observers judged 7 distances, 30-66 in. (76.2-167.6 cm) at 7 eccentricities, 0-18 in. (0-45.7 cm) left and right. Results replicated those of Experiment 1, with nonlinear multiple Rs of .97 and .99 for the 2 participants. Bimanual triangulation supported reliable distance judgments, comparable to binocular distance perception. No evidence of perceptual learning was found.     

The visual perception of length along intrinsically curved surfaces

The ability of observers to perceive three-dimensional (3-D) distances or lengths along intrinsically curved surfaces was investigated in three experiments. Three physically curved surfaces were used: convex and/or concave hemispheres (Experiments 1 and 3) and a hyperbolic paraboloid (Experiment 2). The first two experiments employed a visual length-matching task, but in the final experiment the observers estimated the surface lengths motorically by varying the separation between their two index fingers. In general, the observers' judgments of surface length in both tasks (perceptual vs. motoric matching) were very precise but were not necessarily accurate. Large individual differences (overestimation, underestimation, etc.) in the perception of length occurred. There were also significant effects of viewing distance, type of surface, and orientation of the spatial intervals on the observers' judgments of surface length. The individual differences and failures of perceptual constancy that were obtained indicate that there is no single relationship between physical and perceived distances on 3-D surfaces that is consistent across observers.     

Training Observers to Detect Deception Effects of Self-Monitoring and Rehearsal

It was predicted that trained observers would detect deception more accurately than untrained observers. More specifically, it was predicted that the highest deception detection accuracy would be found among trained observers judging the veracity of low self-monitors and unrehearsed liars, whereas the lowest detection accuracy would be found among untrained observers judging the veracity of high self-monitors and rehearsed deceivers. It also was hypothesized that the discrepancy between observers‘actual ability to detect deception and their certainty in the accuracy of their judgments would be smaller for trained observers than for untrained observers. Observers trained to detect deception used six behavioral cues based on research by deTurck and Miller (1985): (a) message duration, (b) response latency, (c) adaptors, (d) pauses, (e) nonfluencies, and (f) hand gestures. Results confirmed both hypotheses.     

Binocular cues in the perception of distance of a point source of light

The ability to make egocentric distance estimates of a single point source of light, seen in darkness and without the cues of changing size and luminance, was investigated in sixteen observers. The attenuation required to maintain constant luminance, when the target was viewed from different distances, was shown to follow the inverse square law providing the angle subtended by the light was less than 20 s arc. Distance changes were also simulated by means of a split mirror which produced vergence cues, or by test lenses to provide accommodation cues. Over the range 0.5 to 9.2 m distance estimates were surprisingly accurate, although there was some overestimation of near and underestimation of far distances. Most observers made good judgements when only convergence cues were varied, whereas no observers made consistently good judgements when only accommodation cues were varied. The difficulties are discussed in terms of the accommodation-convergence link. When distance was simulated by changing convergence and accommodation cues, estimates were not as good as when real distance was changed. Since good estimates were made with brief target exposures, these judgements were not based on subsequent convergence or accommodation changes. It is suggested that the metric or reference against which the apparently absolute judgements were made was the efferent demand signal associated with a 'resting' position of convergence in darkness.     

The effect of feedback training on distance estimation in virtual environments

It is often noted that distances are significantly underestimated in computer‐simulated (virtual) environments. Two experiments examine observers' ability to use error corrective feedback to improve the accuracy of judgments of egocentric and exocentric distances. In Experiment 1, observers viewed objects in an immersive virtual environment and estimated their distance through a blindfolded walking task. Different groups received feedback on either egocentric, exocentric or none of these judgments. Receiving feedback improved observers' ability to estimate only those distances for which feedback was provided. These effects persisted for at least 1 week. In Experiment 2, observers estimated egocentric distance by means of both a direct and indirect walking task. Receiving feedback on the direct walking task predominantly improved direct estimates and not indirect estimates. These findings suggest that although feedback training offers a relatively straightforward and immediate way of overcoming problems of distance estimation, its effects are specific to both the type of judgment and the type of response. Copyright © 2005 John Wiley & Sons, Ltd.     

Perceiving individuals and groups: expectancies, dispositional inferences, and causal attributions

Two experiments investigated differences in forming impressions of individual and group targets. Experiment 1 showed that when forming an impression of an individual, perceivers made more extreme trait judgments, made those judgments more quickly and with greater confidence, and recalled more information than when the impression target was a group. Experiment 2 showed that when participants were forming an impression of an individual, expectancy-inconsistent behaviors spontaneously triggered causal attributions to resolve the inconsistency; this was not the case when the impression target was a group. Results are interpreted as reflecting perceivers' a priori assumptions of unity and coherence in individual versus group targets.     

Organizational factors and the perception of motion in depth

When two stationary, stereoscopically separated targets are viewed in a completely dark surround, and no cues concerning their egocentric distances from the observer are salient, the farther target tends to be seen at the same distance it would have assumed if it were by itself. The nearer target is seen as being closer than it would have been if seen alone. The present studies extend this previous finding (now termed thefar-anchor effect) into the domain of targets that move in stereoscopic space. Observers viewed two small illuminated targets, which began at either the same or different stereoscopic distances. One of the targets was moved in depth and the observers identified the target that appeared to move. Conditions varied according to the initial depth location of the moving target. Significantly more correct responses were reported when the nearer target moved than when the farther one moved, consistent with the hypothesis that the perception of motion in depth is affected by the aforementioned perceptual anchoring effect of the farther target.     

Perception of personal identity at home

This study aims to discover whether observers with the same cultural background as the inhabitant of a bedroom perceive common characteristics among the inhabitants. The study was carried out with 107 females who were asked to assess the inhabitants of eight bedrooms. Several slides of each bedroom were shown to participants and they had to choose from a list of seventy-six characteristics those that defined the resident of each bedroom. Results revealed that socio-demographic variables thus attributed coincided with the profiles of the inhabitants. A correspondence analysis brought to light a dimension linked to affective aspects, which was more prominent among women; whereas among men the characteristics thus attributed were more linked to practical aspects and to difficulties for social interaction. A second study was conducted to determine whether gender stereotype had any influence on the result of the previous study. The outcomes showed that this stereotype did not have any effect on the participants' judgments.     

Heading judgments in minimal environments: the value of a heuristic when invariants are rare

Observers made systematic heading judgments in two experiments simulating their translation through an environment with only two trees. When those trees converged or decelerated apart, observers tended to follow the invariant information and make heading judgments outside the near member of the pair. When those trees accelerated apart, however, observers tended to follow the heuristic information and make judgments outside the far member, although this result was tempered by the angular separation between the trees and their relative acceleration. The simultaneous existence and use of invariants and heuristics are discussed in terms of different metatheoretical approaches to perception.     

A linear relation between loudness and decibels

A total of 37 uninitiated observers made repeated numerical magnitude judgments of the loudness of a sequence of octave band noises spaced at 1-dB intervals, from 0 to 5 dB above a standard of about 80 dB(A), which was called 10. The observers were not instructed to use numbers as ratios. When the median responses are plotted linearly against decibels, they are fitted by straight lines. Each extra decibel adds an average of 1 unit of loudness, range for individual observers 10 through .25 units. This is consistent with the view that the subjectively equal stimulus spacing for the loudness of noise is linear in decibels, and that the observers use numbers linearly in judging the loudness.     

Comparative judgments of distal size: A chronometric analysis

Observers were required to make comparative judgments of the distal sizes of squares at various perceived distances in a pictorial array. It was predicted that observers would normalize distance prior to judgment. Chronometric analyses indicated that the time to make “same” judgments increased systematically with the relative distance of the two stimuli. The time required to make “different” judgments depended on the nature of the difference. When the stimuli differed in proximal size, distal size, and distance, response time increased with distance ratio. However, when the stimuli differed in distal size and distance but not proximal size, response time decreased with distance ratio. In addition, when the stimuli differed in both distal and proximal size but not distance, RT decreased with size ratio. These results are consistent with a class of models that incorporate distance normalization into the comparative size-judging process. These and alternative models are discussed.     

SELF-MONITORING,REHEARSAL, AND DECEPTIVE COMMUNICATION

This study examined the effects of self-monitoring and rehearsal on the ability of observers to detect deception and on the behavioral correlates of deception. It was hypothesized that observers would be more accurate at detecting deception perpetrated by low self-monitors than by high self-monitors, with the difference particularly pronounced when messages were rehearsed. In addition, low self-monitors communicating spontaneously were expected to display greater rates of verbal and nonverbal responding than high self-monitors who planned their communications. Sixteen high and low self-monitors both lied and told the truth (either spontaneously or after 20-minute rehearsals) regarding their feelings while viewing slides of pleasant landscapes and of disfigured burn victims. Analysis of the responses of the 151 observers who made veracity judgments supported the hypothesis concerning accuracy of deception detection. Coding of 10 verbal and nonverbal behaviors revealed that unrehearsed low self-monitors displayed significantly greater pause and nonfluency rates than rehearsed high self-monitors. Additional findings are reported regarding the effects of self-monitoring, rehearsal, and truthful versus deceptive communication on the behavioral correlates of deception.     

Visual experience, visual field size, and the development of nonvisual sensitivity to the spatial structure of outdoor neighborhoods explored by walking.

When places are explored without vision, observers go from temporally sequenced, circuitous inputs available along walks to knowledge of spatial structure (i.e., straight-line distances and directions characterizing the simultaneous arrangement of the objects passed along the way). Studies show that a life history of vision helps develop nonvisual sensitivity, but they are unspecific on the formative experiences or the underlying processes. This study compared judgments of straight-line distances and directions among landmarks in a familiar area of town by partially sighted persons who varied in types and ages of visual impairment. Those with early childhood loss of broad-field vision and those blind from birth performed significantly worse than those with early or late acuity loss and those with late field loss. Broad-field visual experience facilitates perceptual development by providing a basis for proprioceptive and efferent information from locomotion against distances and directions relative to the surrounding environment. Differences in the perception of walking, in turn, cause the observed differences in sensitivity to spatial structure.     

Escher in color space: individual-differences multidimensional scaling of color dissimilarities collected with a gestalt formation task.

The structure of color perception can be examined by collecting judgments about color dissimilarities. In the procedure used here, stimuli are presented three at a time on a computer monitor and the spontaneous grouping of most-similar stimuli into gestalts provides the dissimilarity comparisons. Analysis with multidimensional scaling allows such judgments to be pooled from a number of observers without obscuring the variations among them. The anomalous perceptions of color-deficient observers produce comparisons that are represented well by a geometric model of compressed individual color spaces, with different forms of deficiency distinguished by different directions of compression. The geometrical model is also capable of accommodating the normal spectrum of variation, so that there is greater variation in compression parameters between tests on normal subjects than in those between repeated tests on individual subjects. The method is sufficiently sensitive and the variations sufficiently large that they are not obscured by the use of a range of monitors, even under somewhat loosely controlled conditions.     

The influence of presentation format and viewer training in the visual arts on the perception of pictorial and aesthetic qualities of paintings

The comparability of viewers' responses to slide-projected and computer-generated images of nine paintings by renowned artists to those obtained from individuals experiencing the originals in the galleries of the New York Metropolitan Museum of Art was investigated. The influence of training in the visual arts upon evaluative judgments made under the three presentation formats was also assessed. Specifically, art-trained and untrained participants in each format condition rated each artwork on sixteen measures of physical and structural characteristics, novelty of content, and aesthetic qualities. Analyses revealed significant differences in the judged hedonic value of the originals as contrasted with the two types of reproduction, whereas trained and untrained participants' evaluations of the pictorial qualities of the artworks were comparable across presentation formats. Findings are discussed in terms of a facsimile-accommodation hypothesis proposed by the authors.