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.

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.

Evaluating Augmented Reality Landmark Cues and Frame of Reference Displays with Virtual Reality.

Daily travel usually demands navigation on foot across a variety of different application domains, including tasks like search and rescue or commuting. Head-mounted augmented reality (AR) displays provide a preview of future navigation systems on foot, but designing them is still an open problem. In this paper, we look at two choices that such AR systems can make for navigation: 1) whether to denote landmarks with AR cues and 2) how to convey navigation instructions. Specifically, instructions can be given via a head-referenced display (screen-fixed frame of reference) or by giving directions fixed to global positions in the world (world-fixed frame of reference). Given limitations with the tracking stability, field of view, and brightness of most currently available head-mounted AR displays for lengthy routes outdoors, we decided to simulate these conditions in virtual reality. In the current study, participants navigated an urban virtual environment and their spatial knowledge acquisition was assessed. We experimented with whether or not landmarks in the environment were cued, as well as how navigation instructions were displayed (i.e., via screen-fixed or world-fixed directions). We found that the world-fixed frame of reference resulted in better spatial learning when there were no landmarks cued; adding AR landmark cues marginally improved spatial learning in the screen-fixed condition. These benefits in learning were also correlated with participants' reported sense of direction. Our findings have implications for the design of future cognition-driven navigation systems.

Visual expertise is more than meets the eye: an examination of holistic visual processing in radiologists and architects.

Purpose: One of the dominant behavioral markers of visual-expert search strategy, holistic visual processing (HVP), suggests that experts process information from a larger region of space in conjunction with a more focused gaze pattern to improve search speed and accuracy. To date, extant literature suggests that visual search expertise is domain specific, including HVP and its associated behaviors. Approach: The current study is the first to use eye tracking to directly measure the HVP strategies of two expert groups, radiologists and architects, in comparison to one another and a novice control. Results: In doing so, we replicated and extended this prior research: visual expertise is domain specific. However, our eye-tracking data indicate that contrary to this prior work, HVP strategies are transferable across domains. Yet, despite the transfer of HVP strategies, there is neither reduced search time nor greater accuracy in visual search outside of an expert's domain. Conclusions: Therefore, our data suggest that HVP behaviors are a particular form of visual search mechanism that, outside of an expert's native search-ecology, are not necessarily conducive to more general visual search success. It is in addition to explicit knowledge of an expert's domain, how to search, and where to search, that HVP strategies are their most effective for visual search success.

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.

Childhood Experience Reduces Gender Differences in Spatial Abilities: A Cross-Cultural Study.

Spatial experience in childhood is a factor in the development of spatial abilities. In this study, we assessed whether American and Faroese participants' (N = 246, Mage = 19.31 years, 151 females) early spatial experience and adult spatial outcomes differed by gender and culture, and if early experience was related to adult performance and behavior. Participants completed retrospective reports on their childhood spatial experience, both large-scale (permitted childhood range size) and small-scale (Lego play). They also completed assessments of their current large-scale spatial behavior (navigational strategy) and small-scale ability (mental rotation task, MRT). We replicated earlier results showing better MRT performance among males and more reliance by males on orientation navigational strategies, although males and females reported similar ranges as children. However, there were cross-cultural differences, with Faroese having larger childhood ranges, less reliance on route strategies, better MRT scores, and a smaller gender difference in MRT. Larger permitted childhood ranges were associated with reduced use of route strategies for navigation in adulthood, and greater Lego play in childhood predicted better MRT performance as adults. There was also some evidence supporting relationships across spatial scales, with more Lego play predicting an orientation style of navigation and larger childhood ranges predicting better performance on the MRT, although the latter was not independent of country. In sum, we observed an association in both cultures between large-scale childhood experience and large-scale behavior in adulthood, small-scale experience in childhood and adult small-scale performance, and some associations between experience and behavior across spatial scales.

Trauma bay virtual reality-A game changer for ATLS instruction and assessment.

BACKGROUND: Medical educational research highlights the need for high-fidelity, multidisciplinary simulation training to teach complex decision-making skills, such as those taught in Advanced Trauma Life Support (ATLS). This approach is, however, expensive and time-intensive. Virtual reality (VR) education simulation may improve skill acquisition in a cost-effective and time-sensitive manner. We developed a novel trauma VR simulator (TVRSim) for providers to apply ATLS principles. We hypothesized in this pilot study that TVRSim could differentiate practitioner competency with increasing experience and would be well accepted. METHODS: Providers at a Level I trauma center (acute care surgeons, novice (MS4 & PGY1), junior (PGY2 & 3), senior (PGY4-6) residents) ran a blunt, polytrauma VR code. Ten critical decision points were assessed: intubation, cricothyroidotomy, chest tube, intravenous access, focused abdominal sonography for trauma examination, pelvic binder, activation of massive transfusion protocol, administration of hypertonic saline, hyperventilation and decision to go to the operating room (OR). Learner assessment was based on frequency and time to correct decisions. Participant satisfaction was measured using validated surveys. RESULTS: All 31 providers intubated and obtained intravenous access. Novices and juniors frequently failed at hypertonic saline and hyperventilation decisions. Juniors often failed at cricothyroidotomy (60%) and OR (100%) decisions. Mean time to all decisions except going to the OR was longer for all groups compared to acute care surgeons. Mean number of decisions/min was significantly higher for surgeons and seniors compared to juniors and novices. Mortality was 92.3% for novices, 80% for juniors, 25% for seniors and 0% for the attendings. Participants found TVRSim comfortable, easy to use/interact with/performance enhancing, and helped develop skills and learning. CONCLUSIONS: In this pilot study using a sample of convenience, TVRSim was able to discern decision-making abilities among trainees with increasing experience. All trainees felt that the platform enhanced their performance and facilitated skill acquisition and learning. TVRSim could be a useful adjunct to teach and assess ATLS skills. LEVEL OF EVIDENCE: Diagnostic Test or Criteria; Level IV.

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.

Shedding Light on Cast Shadows: An Investigation of Perceived Ground Contact in AR and VR.

Virtual objects in augmented reality (AR) often appear to float atop real world surfaces, which makes it difficult to determine where they are positioned in space. This is problematic as many applications for AR require accurate spatial perception. In the current study, we examine how the way we render cast shadows-which act as an important monocular depth cue for creating a sense of contact between an object and the surface beneath it-impacts spatial perception. Over two experiments, we evaluate people's sense of surface contact given both traditional and non-traditional shadow shading methods in optical see-through augmented reality (OST AR), video see-through augmented reality (VST AR), and virtual reality (VR) head-mounted displays. Our results provide evidence that nontraditional shading techniques for rendering shadows in AR displays may enhance the accuracy of one's perception of surface contact. This finding implies a possible tradeoff between photorealism and accuracy of depth perception, especially in OST AR displays. However, it also supports the use of more stylized graphics like non-traditional cast shadows to improve perception and interaction in AR applications.

Through the eyes of the expert: Evaluating holistic processing in architects through gaze-contingent viewing.

Studies in the psychology of visual expertise have tended to focus on a limited set of expert domains, such as radiology and athletics. Conclusions drawn from these data indicate that experts use parafoveal vision to process images holistically. In this study, we examined a novel, as-of-yet-unstudied class of visual experts-architects-expecting similar results. However, the results indicate that architects, though visual experts, may not employ the holistic processing strategy observed in their previously studied counterparts. Participants (n = 48, 24 architects, 24 naïve) were asked to find targets in chest radiographs and perspective images. All images were presented in both gaze-contingent and normal viewing conditions. Consistent with a holistic processing model, we expected two results: (1) architects would display a greater difference in saccadic amplitude between the gaze-contingent and normal conditions, and (2) architects would spend less time per search than an undergraduate control group. We found that the architects were more accurate in the perspectival task, but they took more time and displayed a lower difference in saccadic amplitude than the controls. Our research indicates a disjunctive conclusion. Either architects are simply different kinds of visual experts than those previously studied, or we have generated a task that employs visual expertise without holistic processing. Our data suggest a healthy skepticism for across-the-board inferences collected from a single domain of expertise to the nature of visual expertise generally. More work is needed to determine whether holism is a feature of all visual expertise.

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.

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.

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.

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.

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.

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.