Effects of older age on visual and self-motion sensory cue integration in navigation.

Older adults demonstrate impairments in navigation that cannot be explained by general cognitive and motor declines. Previous work has shown that older adults may combine sensory cues during navigation differently than younger adults, though this work has largely been done in dark environments where sensory integration may differ from full-cue environments. Here, we test whether aging adults optimally combine cues from two sensory systems critical for navigation: vision (landmarks) and body-based self-motion cues. Participants completed a homing (triangle completion) task using immersive virtual reality to offer the ability to navigate in a well-lit environment including visibility of the ground plane. An optimal model, based on principles of maximum-likelihood estimation, predicts that precision in homing should increase with multisensory information in a manner consistent with each individual sensory cue's perceived reliability (measured by variability). We found that well-aging adults (with normal or corrected-to-normal sensory acuity and active lifestyles) were more variable and less accurate than younger adults during navigation. Both older and younger adults relied more on their visual systems than a maximum likelihood estimation model would suggest. Overall, younger adults' visual weighting matched the model's predictions whereas older adults showed sub-optimal sensory weighting. In addition, high inter-individual differences were seen in both younger and older adults. These results suggest that older adults do not optimally weight each sensory system when combined during navigation, and that older adults may benefit from interventions that help them recalibrate the combination of visual and self-motion cues for navigation.

Using virtual reality to assess dynamic self-motion and landmark cues for spatial updating in children and adults.

The relative contribution of different sources of information for spatial updating - keeping track of one's position in an environment - has been highly debated. Further, children and adults may differ in their reliance on visual versus body-based information for spatial updating. In two experiments, we tested children (age 10-12 years) and young adult participants on a virtual point-to-origin task that varied the types of self-motion information available for translation: full-dynamic (walking), visual-dynamic (controller induced), and no-dynamic (teleporting). In Experiment 1, participants completed the three conditions in an indoor virtual environment with visual landmark cues. Adults were more accurate in the full- and visual-dynamic conditions (which did not differ from each other) compared to the no-dynamic condition. In contrast, children were most accurate in the visual-dynamic condition and also least accurate in the no-dynamic condition. Adults outperformed children in all conditions. In Experiment 2, we removed the potential for relying on visual landmarks by running the same paradigm in an outdoor virtual environment with no geometrical room cues. As expected, adults' errors increased in all conditions, but performance was still relatively worse in teleporting. Surprisingly, children showed overall similar accuracy and patterns across locomotion conditions to adults. Together, the results support the importance of dynamic translation information (either visual or body-based) for spatial updating across both age groups, but suggest children may be more reliant on visual information than adults.

A comparison of virtual locomotion methods in movement experts and non-experts: testing the contributions of body-based and visual translation for spatial updating.

Both visual and body-based (vestibular and proprioceptive) information contribute to spatial updating, or the way a navigator keeps track of self-position during movement. Research has tested the relative contributions of these sources of information and found mixed results, with some studies demonstrating the importance of body-based information, especially for translation, and some demonstrating the sufficiency of visual information. Here, we invoke an individual differences approach to test whether some individuals may be more dependent on certain types of information compared to others. Movement experts tend to be dependent on motor processes in small-scale spatial tasks, which can help or hurt performance, but it is unknown if this effect extends into large-scale spatial tasks like spatial updating. In the current study, expert dancers and non-dancers completed a virtual reality point-to-origin task with three locomotion methods that varied the availability of body-based and visual information for translation: walking, joystick, and teleporting. We predicted decrements in performance in both groups as self-motion information was reduced, and that dancers would show a larger cost. Surprisingly, both dancers and non-dancers performed with equal accuracy in walking and joystick and were impaired in teleporting, with no large differences between groups. We found slower response times for both groups with reductions in self-motion information, and minimal evidence for a larger cost for dancers. While we did not see strong dance effects, more participation in spatial activities related to decreased angular error. Together, the results suggest a flexibility in reliance on visual or body-based information for translation in spatial updating that generalizes across dancers and non-dancers, but significant decrements associated with removing both of these sources of information.

Spatial Reference Frame but Neither Age nor Gender Predict Performance on a Water-Level Task in 8- to 11-Year-Old Children.

Successful performance on the water-level task, a common measure of spatial perception, requires adopting an environmental, rather than object-centered, spatial frame of reference. Use of this strategy has not been systematically studied in prepubertal children, a developmental period during which individual differences in spatial abilities start to emerge. In this study, children aged 8 to 11 reported their age and gender, completed a paper-and-pencil water-level task, and drew a map of their neighborhood to assess spontaneous choice of spatial frame of reference. Results showed a surprising lack of age or gender difference in water-level performance, but a significant effect of spatial frame of reference. Although they made up only a small portion of the sample, children who drew allocentric maps had the highest water-level score, with very high accuracy. These results suggest that children who adopt environmental-based reference frames when depicting their familiar environment may also use environmental-based reference frame strategies to solve spatial perception tasks, thereby facilitating highly accurate performance.

Effect of Display Technology on Perceived Scale of Space.

OBJECTIVE: Our goal was to evaluate the degree to which display technologies influence the perception of size in an image. BACKGROUND: Research suggests that factors such as whether an image is displayed stereoscopically, whether a user's viewpoint is tracked, and the field of view of a given display can affect users' perception of scale in the displayed image. METHOD: Participants directly estimated the size of a gap by matching the distance between their hands to the gap width and judged their ability to pass unimpeded through the gap in one of five common implementations of three display technologies (two head-mounted displays [HMD] and a back-projection screen). RESULTS: Both measures of gap width were similar for the two HMD conditions and the back projection with stereo and tracking. For the displays without tracking, stereo and monocular conditions differed from each other, with monocular viewing showing underestimation of size. CONCLUSIONS: Display technologies that are capable of stereoscopic display and tracking of the user's viewpoint are beneficial as perceived size does not differ from real-world estimates. Evaluations of different display technologies are necessary as display conditions vary and the availability of different display technologies continues to grow. APPLICATIONS: The findings are important to those using display technologies for research, commercial, and training purposes when it is important for the displayed image to be perceived at an intended scale.

Evidence for hand-size constancy: the dominant hand as a natural perceptual metric.

The hand is a reliable and ecologically useful perceptual ruler that can be used to scale the sizes of close, manipulatable objects in the world in a manner similar to the way in which eye height is used to scale the heights of objects on the ground plane. Certain objects are perceived proportionally to the size of the hand, and as a result, changes in the relationship between the sizes of objects in the world and the size of the hand are attributed to changes in object size rather than hand size. To illustrate this notion, we provide evidence from several experiments showing that people perceive their dominant hand as less magnified than other body parts or objects when these items are subjected to the same degree of magnification. These findings suggest that the hand is perceived as having a more constant size and, consequently, can serve as a reliable metric with which to measure objects of commensurate size.

Increased Pain Variability in Patients With Chronic Pain: A Role for Pain Catastrophizing.

Pain is an inherently negative perceptual and affective experience that acts as a warning system to protect the body from injury and illness. Pain unfolds over time and is influenced by myriad factors, making it highly dynamic. Despite this, statistical measures often treat any intraindividual variability in pain ratings as noise or error. This is consequential, especially for research on chronic pain, because pain variability is associated with greater pain severity and depression. Yet, differences in pain variability between patients with chronic pain and controls in response to acute pain has not been fully examined-and it is unknown if dispositional factors such as pain catastrophizing (negative cognitive-affective response to potential or actual pain in which attention cannot be diverted away from pain) relate to pain variability. In the current study, we recruited chronic-pain patients (N = 30) and pain-free controls (N = 22) to complete a 30-second thermal pain task where they continually rated a painful thermal stimulus. To quantify pain variability and capture potential dynamics, we used both a traditional intraindividual standard deviation (iSD) metric of variability and a novel derivatives approach. For both metrics, patients with chronic pain had higher variability in their pain ratings over time, and pain catastrophizing significantly mediated this relationship. This suggests patients with chronic pain experience pain stimuli differently over time, and pain catastrophizing may account for this differential experience. PERSPECTIVE: The present study demonstrates (using multiple variability metrics) that chronic pain patients show more variability when rating experimental pain stimuli, and that pain catastrophizing helps explain this differential experience. These results provide preliminary evidence that short-term pain variability could have utility as a clinical marker in pain assessment and treatment.

The addition of a spatial auditory cue improves spatial updating in a virtual reality navigation task.

Auditory cues are integrated with vision and body-based self-motion cues for motion perception, balance, and gait, though limited research has evaluated their effectiveness for navigation. Here, we tested whether an auditory cue co-localized with a visual target could improve spatial updating in a virtual reality homing task. Participants navigated a triangular homing task with and without an easily localizable spatial audio signal co-located with the home location. The main outcome was unsigned angular error, defined as the absolute value of the difference between the participant's turning response and the correct response towards the home location. Angular error was significantly reduced in the presence of spatial sound compared to a head-fixed identical auditory signal. Participants' angular error was 22.79° in the presence of spatial audio and 30.09° in its absence. Those with the worst performance in the absence of spatial sound demonstrated the greatest improvement with the added sound cue. These results suggest that auditory cues may benefit navigation, particularly for those who demonstrated the highest level of spatial updating error in the absence of spatial sound.

Perceiving distance in virtual reality: theoretical insights from contemporary technologies.

Decades of research have shown that absolute egocentric distance is underestimated in virtual environments (VEs) when compared with the real world. This finding has implications on the use of VEs for applications that require an accurate sense of absolute scale. Fortunately, this underperception of scale can be attenuated by several factors, making perception more similar to (but still not the same as) that of the real world. Here, we examine these factors as two categories: (i) experience inherent to the observer, and (ii) characteristics inherent to the display technology. We analyse how these factors influence the sources of information for absolute distance perception with the goal of understanding how the scale of virtual spaces is calibrated. We identify six types of cues that change with these approaches, contributing both to a theoretical understanding of depth perception in VEs and a call for future research that can benefit from changing technologies. This article is part of the theme issue 'New approaches to 3D vision'.

The perceived duration of vast spaces is mediated by awe.

Looking out over the Pacific Ocean or the Grand Canyon can lead to a sense of vastness. As a perceptual phenomenon, vastness poses a unique challenge because traditional measures of distance are not capable of explaining such large spatial extents. Vastness, however, may lead to a sense of awe, and awe, in turn, can dilate one's experience of time. Time, then, may be a meaningful proxy measure of vastness. Whether vastness is related to the perception of time and if the emotional experience of awe plays a role in that relation was explored herein. Across three experiments, we examined the relation between vastness, awe, and perceived time. In Experiment 1, participants reproduced the perceived duration of images varying in vastness and rated them in terms of the awe experienced as if they were in the spaces. Greater vastness led to higher awe scores and longer duration estimates, with awe mediating the relation between vastness and time. Experiment 2 assessed if the average brightness of images, absent of scene structure, explained changes in perceived duration. Brightness did not explain variance in perceived duration; thus, the scene structure of vast scenes may play a role in altering perceived time. Experiment 3 examined if scene semantics could explain changes in perceived duration. Whereas the relation between vastness and perceived duration vanished, a weak, mediated effect still occurred. Ultimately, time may not be a proxy measure of vastness, but we find evidence that emotion can link the relation between spatial and temporal perception.

The relationship between space and time perception: A registered replication of Casasanto and Boroditsky (2008).

Everything in our environment moves through both space and time, and to effectively act we must be aware of both spatial and temporal elements in relation to our own body. Thus, perception of space and time have an intimate relationship. Walsh's a theory of magnitude (ATOM) suggests that space and time perception rely on a general magnitude system and their relationship should be roughly symmetrical. Alternatively, metaphor theory, which is based on the philosophical work of Lakoff and Johnson, argues that we represent time using spatial metaphor and thus the relationship should be asymmetrical (with space influencing time more than time influences space). A compelling line of evidence for metaphor theory comes from the work of Casasanto and Boroditsky who experimentally demonstrated this asymmetric effect. However, in our previous unpublished online replication attempt of this work, we found a roughly symmetrical relationship between space and time, more in line with the theoretical predictions of ATOM. Given this, we performed a registered replication of Casasanto and Boroditsky (2008) in both an online and laboratory environment.

An effect of mood on the perception of geographical slant.

Previous research has shown that hills appear steeper to those who are fatigued, encumbered, of low physical fitness, elderly, or in declining health (Bhalla & Proffitt, 1999; Proffitt, Bhalla, Gossweiler, & Midgett, 1995). The prevailing interpretation of this research is that observers' perceptions of the environment are influenced by their capacity to navigate that environment. The current studies extend this programme by investigating more subtle embodied effects on perception of slant; namely those of mood. In two studies, with two different mood manipulations, and two estimates of slant in each, observers in a sad mood reported hills to be steeper. These results support the role of mood and motivational factors in influencing spatial perception, adding to the previous work showing that energetic potential can influence perception.

Don't look down: emotional arousal elevates height perception.

In a series of experiments, it was found that emotional arousal can influence height perception. In Experiment 1, participants viewed either arousing or nonarousing images before estimating the height of a 2-story balcony and the size of a target on the ground below the balcony. People who viewed arousing images overestimated height and target size more than did those who viewed nonarousing images. However, in Experiment 2, estimates of horizontal distances were not influenced by emotional arousal. In Experiment 3, both valence and arousal cues were manipulated, and it was found that arousal, but not valence, moderated height perception. In Experiment 4, participants either up-regulated or down-regulated their emotional experience while viewing emotionally arousing images, and a control group simply viewed the arousing images. Those participants who up-regulated their emotional experience overestimated height more than did the control or down-regulated participants. In sum, emotional arousal influences estimates of height, and this influence can be moderated by emotion regulation strategies. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Asymmetrical body perception: a possible role for neural body representations.

Perception of one's body is related not only to the physical appearance of the body, but also to the neural representation of the body. The brain contains many body maps that systematically differ between right- and left-handed people. In general, the cortical representations of the right arm and right hand tend to be of greater area in the left hemisphere than in the right hemisphere for right-handed people, whereas these cortical representations tend to be symmetrical across hemispheres for left-handers. We took advantage of these naturally occurring differences and examined perceived arm length in right- and left-handed people. When looking at each arm and hand individually, right-handed participants perceived their right arms and right hands to be longer than their left arms and left hands, whereas left-handed participants perceived both arms accurately. These experiments reveal a possible relationship between implicit body maps in the brain and conscious perception of the body.

The roles of altitude and fear in the perception of height.

Previous research on perceiving spatial layout has found that people often exhibit normative biases in their perception of the environment. For instance, slant is typically overestimated and distance is usually underestimated. Surprisingly, however, the perception of height has rarely been studied. The present experiments examined the perception of height when viewed from the top (e.g., looking down) or from the bottom (e.g., looking up). Multiple measures were adapted from previous studies of horizontal extents to assess the perception of height. Across all of the measures, a large, consistent bias was found: Vertical distances were greatly overestimated, especially from the top. Secondary findings suggest that the overestimation of distance and size that occurs when looking down from a high place correlates with reports of trait- and state-level fear of heights, suggesting that height overestimation may be due, in part, to fear.

Anxiety Influences the Perceptual-Motor Calibration of Visually Guided Braking to Avoid Collisions.

We investigated whether anxiety influences perceptual-motor calibration in a braking to avoid a collision task. Participants performed either a discrete braking task (Experiment 1) or a continuous braking task (Experiment 2), with the goal of stopping before colliding with a stop sign. Half of participants performed the braking task after an anxiety induction. We investigated whether anxiety reduced the frequency of crashing and if it influenced the calibration of perception (visual information) and action (brake pressure) dynamically between-trials in Experiment 1 and within-trials in Experiment 2. In the discrete braking task, anxious participants crashed less often and made larger corrective adjustments trial-to-trial after crashing, suggesting that the influence of anxiety on behavior did not occur uniformly, but rather dynamically with anxiety amplifying the reaction to previous crashes. However, when performing continuous braking, anxious participants crashed more often, and their within-trial adjustments of deceleration were less related to visual information compared to controls. Taken together, these findings suggest that the timescale and nature of the task mediates the influence of anxiety on the performance of goal-directed actions.

Gender differences in spatial navigation: Characterizing wayfinding behaviors.

Men show a consistent spatial navigation advantage over women, which is often attributed to their increased use of survey spatial strategies. But what about men's navigation gives them an advantage? One possibility is that the way in which men explore environments is fundamentally different, leading to better navigational performance. To test this possibility, this study investigated whether there are gender differences in wayfinding behaviors during navigation that relate to navigational success in a real-world, large-scale, unconstrained navigation task. West Point cadets were given a masked GPS tracker and sent into a large-scale, natural environment to locate targets indicated on maps. We assessed how they explored the environment by computing three measures from the GPS tracks and related these measures to their ability to find the assigned target locations. We also tested whether their self-reported spatial ability related to navigational success. Results showed that males performed better than females, which replicates prior work. Further, traveling longer distances without changing course, pausing less, and fewer returns to previously visited locations were significantly related to the ability to locate the correct target. Consistent with full mediation, the significant relationship between gender and navigational success is fully accounted for by men and women producing different wayfinding behaviors, which in turn predict differences in navigational success. Further, there was no unique relationship between self-reported spatial skills and navigational success. This study is a first step toward showing the relationship between gender, wayfinding behaviors, and navigational success in a natural, real-world navigation task.

Mind the Gap: Gap Affordance Judgments of Children, Teens, and Adults in an Immersive Virtual Environment.

Affordances are possibilities for action that depend on both an observer's capabilities and the properties of the environment. Immersive Virtual Environments (IVEs) have been used to examine affordances in adults, demonstrating that judgments about action capabilities are made similarly to the real world. However, less is known about affordance judgments in middle-aged children and adolescents in IVEs. Differences in rate of growth, decision criteria, and perceived risk could influence affordance judgments for children. In Experiment 1, children, teens, and adults stood in an IVE at ground level or at a height of 15 m, and were asked to view gaps of different widths. Across all age groups, estimates of gap crossing were underestimated at the higher height compared to the ground, consistent with reports of fear and risk of falling. Children, compared to adults, underestimated their maximum crossable gap compared to their actual crossable gap. To test whether this difference was specific to IVEs or a more generalized age effect, children and adults were tested on gap estimates in the real world in Experiment 2. This real world study showed no difference between children and adults, suggesting a unique contribution of the IVE to children's affordance judgments. We discuss the implications for using IVEs to study children's affordances.

A new mode of fear expression: perceptual bias in height fear.

Emotion and psychopathology researchers have described the fear response as consisting of four main components--subjective affect, physiology, cognition, and behavior. The current study provides evidence for an additional component in the domain of height fear (perception) and shows that it is distinct from measures of cognitive processing. Individuals High (N = 35) and Low (N = 36) in acrophobic symptoms looked over a two-story balcony ledge and estimated its vertical extent using a direct height estimation task (visual matching), and an indirect task (size estimation); the latter task seems to exhibit little influence from cognitive factors. In addition, implicit and explicit measures of cognitive processing were obtained. Results indicated that, as expected, the High Fear group showed greater relative, implicit height fear associations and explicit threat cognitions. Of primary interest, the High (compared to Low) Fear group estimated the vertical extent to be higher, and judged target sizes to be greater, even when controlling for the cognitive bias measures. These results suggest that emotional factors such as fear are related to perception.

Decision making with visualizations: a cognitive framework across disciplines.

Visualizations-visual representations of information, depicted in graphics-are studied by researchers in numerous ways, ranging from the study of the basic principles of creating visualizations, to the cognitive processes underlying their use, as well as how visualizations communicate complex information (such as in medical risk or spatial patterns). However, findings from different domains are rarely shared across domains though there may be domain-general principles underlying visualizations and their use. The limited cross-domain communication may be due to a lack of a unifying cognitive framework. This review aims to address this gap by proposing an integrative model that is grounded in models of visualization comprehension and a dual-process account of decision making. We review empirical studies of decision making with static two-dimensional visualizations motivated by a wide range of research goals and find significant direct and indirect support for a dual-process account of decision making with visualizations. Consistent with a dual-process model, the first type of visualization decision mechanism produces fast, easy, and computationally light decisions with visualizations. The second facilitates slower, more contemplative, and effortful decisions with visualizations. We illustrate the utility of a dual-process account of decision making with visualizations using four cross-domain findings that may constitute universal visualization principles. Further, we offer guidance for future research, including novel areas of exploration and practical recommendations for visualization designers based on cognitive theory and empirical findings.