Assessing auditory distance perception using perceptually directed action

Three experiments investigated auditory distance perception under natural listening conditions in a large open field. Targets varied in egocentric distance from 3 to 16 m. By presenting visual targets at these same locations on other trials, we were able to compare visual and auditory distance perception under similar circumstances. In some experimental conditions, observers made verbal reports of target distance. In others, observers viewed or listened to the target and then, without further perceptual information about the target, attempted to face the target, walk directly to it, or walk along a two-segment indirect path to it. The primary results were these. First, the verbal and walking responses were largely concordant, with the walking responses exhibiting less between-observer variability. Second, different motoric responses provided consistent estimates of the perceived target locations and, therefore, of the initially perceived distances. Third, under circumstances for which visual targets were perceived more or less correctly in distance using the more precise walking response, auditory targets were generally perceived with considerable systematic error. In particular, the perceived locations of the auditory targets varied only about half as much in distance as did the physical targets; in addition, there was a tendency to underestimate target distance, except for the closest targets.     

The role of suggested size in distance responses

A number of studies have concluded that suggested size can modify perceived size, as indicated by the effect on perceived distance. At least this effect seems to occur when verbal reports are used as the measure of the judged distance of the target. The present study supports a different explanation of this phenomenon. It is hypothesized that suggested size can result in the judgment that the target is larger or smaller than normal (an off-sized judgment) where normal is specified by the suggested size. Because the observer expects that a target judged as a small or large off-sized object must be at a greater or lesser distance, respectively. than its perceived distance, the off-sized judgment can provide a cognitive modification of reported distance. This explanation was tested by measuring the perceived distance of targets using a procedure (called the head motion procedure) that, in contrast with verbal reports of distance, is very unlikely to be influenced by off-sized judgments. Measures obtained with the head motion procedure, unlike those obtained from verbal reports, did not change with changes in the suggested size. It is concluded that the size suggestions had a cognitive, not a perceptual, effect on responses to the distance (and size) of the targets.     

Watch this! Observed tool use affects perceived distance

Recent research has shown that being able to interact with an object causes it to be perceived as being closer than objects that cannot be interacted with. In the present study, we examined whether that compression of perceived space would be experienced by people who simply observed such interactions by others with no intention of performing the action themselves. Participants judged the distance to targets after observing an actor reach to an otherwise unreachable target with a tool (Experiment 1) or illuminate a distant target with a laser pointer (Experiment 2). Observing either type of interaction caused a compression of perceived space, revealing that a person’s perception of space can be altered through mere observation. These results indicate that shared representations between an actor and observer are engaged at the perceptual level easily and perhaps automatically, even in the absence of cooperation or an observer’s own intention to interact.     

Perceived distance of targets in convex mirrors

We investigated the perceived distance of targets in convex and plane mirrors. In Experiment 1, 20 subjects matched the distance of targets in a real scene to the distance of a virtual target in different mirrors. The matched distances were much larger for convex mirrors than for a plane mirror. In Experiment 2, 20 subjects viewed two targets in a mirror and adjusted their own positions so that the distance to the closer target was perceived to equal the distance between the targets. The mean distance to the closer target was smaller for the convex mirrors than for the plane mirror. In Experiment 3, 20 subjects adjusted the position of a target so that the distance to it in a mirror was perceived to equal the distance designated by the experimenter. The best-fitting power functions showed that the scaling factors were larger for the convex mirrors than for the plane mirror, but the exponents were smaller for the convex mirrors than for the plane mirror. It is suggested that distance in the convex mirrors was perceived to be larger than in the plane mirror, and that the growth of perceived distance in the convex mirrors was slower than in the plane mirror.     

The perception of size and distance under monocular observation

A relative-perceived-size hypothesis is proposed to account for the perception of size and distance under monocular observation in reduced-cue settings. This hypothesis is based on two assumptions. In primary processing, perceived size is determined by both proximal stimulation on the retina and distance information from primary cues such as oculomotor cues. In secondary processing, the relation of two primary perceived sizes determines another relation of secondary perceived distances, so that an object of smaller primary perceived size is judged to be further away. An experiment was designed to test this hypothesis, especially the assumption of secondary processing, by making ratio judgments of perceived size and perceived distance for two successively presented targets. The Standard square was presented at a constant distance and varied in visual angle; the variable square was presented with a constant visual angle in distance. The results showed that an inverse relation between size and distance estimates held regardless of whether the visual angles of the targets were the same or different.     

The effect of retinal size on the perception of distance in photographs

The effect of the retinal size of a target on the perception of absolute distance to a single target and relative distance between near and far targets was examined with photographic displays including two persons. Retinal size was systematically varied by varying the focal length of the camera lens, the display size, and the viewing distance. The results showed that, although the relationship between the perceived absolute distance and retinal size was not inversely proportional, the perceived absolute distance decreased with an increase in retinal size. This was more evident when the retinal size was changed by varying the focal length. These results suggest that the determinants of the perceived absolute distance were not only the retinal size of the target but also its ratio to the overall display. The results also showed that the perceived relative distances were little influenced by retinal size, but were strongly dependent on the size ratio of the two targets in the display.     

Revisiting the effect of quality of graphics on distance judgments in virtual environments: A comparison of verbal reports and blind walking

In immersive virtual environments, judgments of perceived egocentric distance are significantly underestimated, as compared with accurate performance in the real world. Two experiments assessed the influence of graphics quality on two distinct estimates of distance, a visually directed walking task and verbal reports. Experiment 1 demonstrated a similar underestimation of distances walked to previously viewed targets in both low- and high-quality virtual classrooms. In Experiment 2, participants’ verbal judgments underestimated target distances in both graphics quality environments but were more accurate in the high-quality environment, consistent with the subjective impression that high-quality environments seem larger. Contrary to previous results, we suggest that quality of graphics does influence judgments of distance, but only for verbal reports. This behavioral dissociation has implications beyond the context of virtual environments and may reflect a differential use of cues and context for verbal reports and visually directed walking.     

An indirect method of measuring perceived distance from familiar size

Two methods of measuring perceived distance as a function of familiar size were compared in five experiments. The method which uses the perception of motion concomitant with a motion of the head, unlike the method of verbal report, is considered to provide a measure of perceived distance that is unaffected by factors of cognitive distance. The results of the experiments indicate that although the perceived egocentric distance of an object can vary somewhat as a function of the cue of familiar size, the larger variation often found with verbal reports of distance is based upon cognitive, not perceptual, information. The cognitive information is interpreted as resulting from the perception of the object as off-sized and the observer’s assumption that the perceived size of an object will vary inversely with its physical distance.     

Perceived size and distance as a perceptual conflict between two processing modes

Three different sized squares were successively presented at the same physical distance under three observational conditions which provided different information about distance in the visual field. The 60 observers in each observational condition were asked to give verbal absolute judgments of perceived size and perceived distance for each of the squares. The results showed that in a full-cue situation a ratio of perceived absolute sizes is equal to that of the corresponding visual angles, with perceived distances appearing equal to each other; in a reduced-cue situation an object of smaller perceived size is judged to be farther away than one of larger perceived size, with the observers tending to assume the two objects as the same object or identically sized objects. These results were analyzed in terms of the perceptual conflict between primary perception and secondary perception.     

An indirect measure of perceived distance from oculomotor cues

The sensitivity of an indirect method of measuring perceived distance was compared in two experiments with the direct procedure of eliciting verbal reports of distance. Perceived distance was varied by varying the oculomotor cues to object distance. The indirect method, called the “adjustable pivot method,” uses an apparatus that physically moves the stimulus object laterally concomitantly with the lateral motion of the head. The magnitude and direction of this concomitant motion determines the distance of the point around which the direction of gaze to the object rotates (the pivot distance) as the head is moved. The pivot distance at which the object appears stationary with head movement measures the apparent distance of the object. Both types of measures were found to vary systematically with the oculomotor distance of the object for points of light (Experiment 1) and extended objects (Experiment 2). A previous study has shown that the adjustable pivot method avoids cognitive errors that can distort verbal reports of distance. The present study, by demonstrating the discriminative capability of this method under conditions in which differences in perceived distance were expected to occur, provides clear evidence that the adjustable pivot method is a sensitive and useful procedure for measuring perceived distance.     

Judgments of exocentric direction in large-scale space

Judgments of exocentric direction are quite common, especially when judging where others are looking or pointing. To investigate these judgments in large-scale space, observers were shown two targets in a large open field and were asked to judge the exocentric direction specified by the targets. The targets ranged in egocentric distance from 5 to 20 m with target-to-target angular separations of 45 degrees, 90 degrees, and 135 degrees. Observers judged exocentric direction using two methods: (i) by judging which point on a distant fence appeared collinear with the two targets, and (ii) by orienting their body in a direction parallel with the perceived line segment. In the collinearity task, observers had to imagine the line connecting the targets and then extrapolate this imagined line out to the fence. Observers indicated the perceived point of collinearity on a handheld 360 degrees panoramic cylinder representing their vista. The two judgment methods gave similar results except for a constant bias associated with the body-pointing response. Aside from this bias, the results of these two methods agree with other existing research indicating an effect of relative egocentric distance to the targets on judgment error--line segments are perceived as being rotated in depth. Additionally, verbal estimates of egocentric and exocentric distance suggest that perceived distance is not the cause for the systematic errors in judging exocentric direction.     

The common occurrence of errors of perceived distance

The effect on the perceived distance of a test object of fixating to a distance different from that of the test object was investigated using monocular observation and two methods for measuring perceived distance. One method, the size adjustment procedure, applying the size-distance invariance hypothesis, measured perceived distance by measuring perceived size. The results from this method were compared with those from a head-motion procedure which used the apparent concomitant motion resulting from head motion to measure perceived distance. The results from both procedures indicated that the apparent distance of the test object physically located at a constant distance varied directly as a function of the fixation distance. This occurred despite the presence of texture on the walls and floor of the visual alley. These and other perceptual effects are interpreted as demonstrating that errors in perceived distance (contrary to the theory of direct perception) are a common occurrence in ordinary visual fields.     

社会合作信息对距离知觉的影响

为探讨社会合作信息对距离知觉的影响,本研究通过两个实验,采用动态追逐场景,对两个追逐者之间的交互模式(或合作或单独追逐同一目标)与追逐目标的存在与否进行了操作。结果发现,相比随机运动和单独追逐,存在合作关系的两个追逐者间的距离被知觉得更远,即存在距离的扩张效应(实验1),且该效应不能由底层的物理特征所解释(实验2)。该结果揭示,社会合作信息使得知觉距离被扩张,其可帮助理解视觉的适应性机制。     

Using verbal and blind-walking distance estimates to investigate the two visual systems hypothesis

Verbal estimates of egocentric distance are usually too short at distances greater than several meters, yet blindfolded walking to previously viewed targets can be surprisingly accurate. We present evidence from three experiments for the existence of two visual pathways with differentencodings of perceived egocentric distance. We found that (1) blind-walking estimates of egocentric distance are consistently more accurate than verbal reports; (2) an indoor versus outdoor environment selectively influences verbal reports; and (3) wearing prism lenses, which displace the visual field vertically, selectively influences the blind-walking estimates. We interpret these results in terms of the two visual systems hypothesis.     

Concomitant direction and distance aftereffects of sustained convergence: A muscle potentiation explanation for eye-specific adaptation

Fixating a target for 6 min was shown to produce distance aftereffects that varied in direction and magnitude as a linear function of the convergence angle. Eye-specific direction aftereffects also were obtained in a nasal direction under conditions that produce increased perceived distance and in a temporal direction under conditions that produce decreased perceived distance. These aftereffects were shown to be sensitive to the range of horizontal versional eye movements that accompany the near or far convergence positions maintained during exposure. The results provide a logical alternative to perceptual learning accounts of eye-specific adaptation.     

Does energy expenditure affect the perception of egocentric distance? A failure to replicate experiment 1 of Proffitt, Stefanucci, Banton, and Epstein (2003)

In a series of recent studies, Proffitt and his colleagues have reported that the perceived distance to a target is influenced by the energy expenditure associated with any action, such as walking or throwing, for spanning the distance to the target. In particular, Proffitt, Stefanucci, Banton, and Epstein (2003) reported that wearing a heavy backpack caused verbal reports of distance to increase. We conducted a study to determine whether three responses dependent on perceived distance (verbal report of distance, blind walking, and estimates of object size) are influenced by the backpack manipulation. In two experiments, one involving a between-participants design and the other involving a within-participants design, we found that none of the three responses were influenced by the wearing of a heavy backpack.     

Relative cues and absolute distance perception

It is possible, in theory, for the simultaneous occurrence of several different relative cues of distances to increase the veridicality of the perception of absolute distance. To test whether this actually occurs, a three-dimensional display was viewed monocularly while moving the head laterally, under conditions in which some error in perceived absolute distance was expected. The perceived absolute distance of the display was measured with the number of relative cues of distance within the display varied. No systematic reduction was found in the error in perceived absolute distance as a consequence of the variation in the number of relative cues. The study provides no evidence that the potential source of absolute distance information provided by relative cues is utilized by the visual system.     

Semantic distance and single cue use in category search

Perceptual classification may be based either on the physical features of target and background items or on the semantic attributes of the presented items. In this paper we used enumeration tasks to study the role of semantic features in a categorial classification task. This means that subjects were asked to count the number of target words in a display belonging to one semantic category among a number of background items of other categories. Our goal was to study the decision logic in category search by manipulating target background conditions and the semantic distance between target and background classes. In the first experiment we found that the larger the semantic distance between targets and background words, the easier it was to find the targets. In the second experiment we found a "pop-out" effect, in which subjects could use and benefit from a single distinctive semantic feature, "part-likeness", in categorial classification. The results of the two experiments imply that the categorization decision logic is basically the same in physical and semantic perceptual classification.     

The impact of changes in spatial distance on emotional responses

Drawing on motivational approaches to emotion, the authors propose that the perceived change in spatial distance to pictures that arouse negative emotions exerts an influence on the significance of these pictures. Two experiments induced the illusion that affective pictures approach toward the observer, recede from the observer, or remain static. To determine the motivational significance of the pictures, emotional valence and arousal ratings as well as startle responses were assessed. Approaching unpleasant pictures were found to exert an influence on both the valence and the arousal elicited by the pictures. Furthermore, movement of pleasant or neutral pictures did not influence startle responses, while the second experiment showed that approaching unpleasant pictures elicited enhanced startle responses compared to receding unpleasant pictures. These findings support the view that a change of spatial distance influences motivational significance and thereby shapes emotional responses.