Visual landmarks facilitate rodent spatial navigation in virtual reality environments

Because many different sensory modalities contribute to spatial learning in rodents, it has been difficult to determine whether spatial navigation can be guided solely by visual cues. Rodents moving within physical environments with visual cues engage a variety of nonvisual sensory systems that cannot be easily inhibited without lesioning brain areas. Virtual reality offers a unique approach to ask whether visual landmark cues alone are sufficient to improve performance in a spatial task. We found that mice could learn to navigate between two water reward locations along a virtual bidirectional linear track using a spherical treadmill. Mice exposed to a virtual environment with vivid visual cues rendered on a single monitor increased their performance over a 3-d training regimen. Training significantly increased the percentage of time avatars controlled by the mice spent near reward locations in probe trials without water rewards. Neither improvement during training or spatial learning for reward locations occurred with mice operating a virtual environment without vivid landmarks or with mice deprived of all visual feedback. Mice operating the vivid environment developed stereotyped avatar turning behaviors when alternating between reward zones that were positively correlated with their performance on the probe trial. These results suggest that mice are able to learn to navigate to specific locations using only visual cues presented within a virtual environment rendered on a single computer monitor.     

Considering spatial ability in virtual route learning in early aging

The aim of this study is to broaden our understanding of the construction and early decline of spatial mental representations in route learning, considering the extent to which spatial ability and age-related differences in environment learning interact. The experiment examines spatial mental representation derived from taking a realistic route acquired using virtual environment and compares individuals different in age but with similar spatial ability. A sample of 34 young (20–30 years) and 30 middle-aged (50–60 years) females with good mental rotation ability were chosen. Participants learned a complex route through its presentation in a virtual environment and then performed a series of tasks (landmark recognition, location of landmarks and verification of spatial relations). Results show that the two participant age groups had similar performance in landmark recognition task and in verification of sentences describing direct spatial relations; instead, the middle-aged group showed a poorer performance than younger in their ability to locate landmarks and to judge the truth of indirect spatial sentences. These results first suggest that spatial abilities have to be seriously considered to avoid any confusion with age, as age-related differences are attenuated when individuals are different in age but similar in spatial ability. Second they confirm a specific difficulty of older participants to handle spatial information in a global configuration.     

Use of virtual environments to investigate development of spatial behavior and spatial knowledge of school-age children

This review aims to show the potential of using virtual environments in developmental spatial cognition research to advance empirical knowledge and theoretical insight. The facility for easy and economic variations of environmental features, the active, self-determined exploration, and the reliable registration of the navigation behavior using virtual environments allow investigating the development of spatial behavior and spatial knowledge in more detail. As a consequence, a dissociation between spatial behavior and spatial knowledge was observed, leading to the conclusion that spatial context has to be integrated further in any theoretical model regarding development of spatial cognition.     

Evidence against integration of spatial maps in humans: generality across real and virtual environments

A real-world open-field search task was implemented with humans as an analogue of Blaisdell and Cook’s (Anim Cogn 8:7–16, 2005) pigeon foraging task and Sturz, Bodily, and Katz’s (Anim Cogn 9:207–217, 2006) human virtual foraging task to 1) determine whether humans were capable of integrating independently learned spatial maps and 2) make explicit comparisons of mechanisms used by humans to navigate real and virtual environments. Participants searched for a hidden goal located in one of 16 bins arranged in a 4 × 4 grid. In Phase 1, the goal was hidden between two landmarks (blue T and red L). In Phase 2, the goal was hidden to the left and in front of a single landmark (blue T). Following training, goal-absent trials were conducted in which the red L from Phase 1 was presented alone. Bin choices during goal-absent trials assessed participants’ strategies: association (from Phase 1), generalization (from Phase 2), or integration (combination of Phase 1 and 2). Results were inconsistent with those obtained with pigeons but were consistent with those obtained with humans in a virtual environment. Specifically, during testing, participants did not integrate independently learned spatial maps but used a generalization strategy followed by a shift in search behavior away from the test landmark. These results were confirmed by a control condition in which a novel landmark was presented during testing. Results are consistent with the bulk of recent findings suggesting the use of alternative navigational strategies to cognitive mapping. Results also add to a growing body of literature suggesting that virtual environment approaches to the study of spatial learning and memory have external validity and that spatial mechanisms used by human participants in navigating virtual environments are similar to those used in navigating real-world environments.     

How different spatial representations interact in virtual environments: the role of mental frame syncing

This experiment is aimed at understanding how egocentric experiences, allocentric viewpoint-dependent representations, and allocentric viewpoint-independent representations interact when encoding and retrieving a spatial environment. Although several cognitive theories have highlighted the interaction between reference frames, it is less clear about the role of a real-time presentation of allocentric viewpoint-dependent representation on the spatial organization of information. Sixty participants were asked to navigate in two virtual cities to memorize the position of one hidden object. Half of the participants had the possibility to visualize the virtual city with an interactive aerial view. Then, they were required to find the position of the object in three different experimental conditions (“retrieval with an interactive aerial view” vs. “retrieval on a map” vs. “retrieval without an interactive aerial view”). Results revealed that participants were significantly more precise in retrieving the position of the object when immersed in an egocentric experience with the interactive aerial view. The retrieval of spatial information is facilitated by the presence of the interactive aerial view of the city, since it provides a real-time allocentric viewpoint-dependent representation. More participants with high preference for using cardinal points tend to be more accurate when they were asked to retrieve the position of the object on the map. As suggested by the mental frame syncing hypothesis, the presence of an allocentric viewpoint-dependent representation during the retrieval seems to ease the imposition on a specific viewpoint on the stored abstract allocentric viewpoint-independent representation. Our findings represent another significant step toward the comprehension of the organization of spatial representations of our environment.     

Three-dimensional virtual environments for blind children.

Information technologies are increasingly helping to integrate and socially include people with visual disabilities. Computing technologies have contributed grandly to attain this goal through innovative techniques and applications. Virtual environments, I/O interfaces, and sound based applications altogether with usability and cognitive impact studies are some of the most used research designs for children with visual disabilities. This study presents the design and usability evaluation of three-dimensional (3D) interactive environments for children with visual disabilities. We introduce AudioChile and AudioVida, interactive virtual environments that can be navigated through 3D sound to enhance spatiality and immersion throughout the environments 3D sound is used to orientate, to avoid obstacles, and to identify the position of diverse personages and objects within the environment. Usability evaluation results indicated that sound can be fundamental for attention and motivation purposes during interaction.     

Interpersonal distance in immersive virtual environments

Digital immersive virtual environment technology (IVET) enables behavioral scientists to conduct ecologically realistic experiments with near-perfect experimental control. The authors employed IVET to study the interpersonal distance maintained between participants and virtual humans. In Study 1, participants traversed a three-dimensional virtual room in which a virtual human stood. In Study 2, a virtual human approached participants. In both studies, participant gender, virtual human gender, virtual human gaze behavior, and whether virtual humans were allegedly controlled by humans (i.e., avatars) or computers (i.e., agents) were varied. Results indicated that participants maintained greater distance from virtual humans when approaching their fronts compared to their backs. In addition, participants gave more personal space to virtual agents who engaged them in mutual gaze. Moreover, when virtual humans invaded their personal space, participants moved farthest from virtual human agents. The advantages and disadvantages of IVET for the study of human behavior are discussed.     

The locus of sex differences in spatial ability

College men and women judged whether pairs of stimuli were identical or mirror images. One stimulus of a pair was presented upright; the other was rotated 0°–150° from the vertical. The stimuli were either alphanumeric symbols or unfamiliar letter-like characters of the type found on the Primary Mental Abilities Spatial Relations Test. For each individual, the linear function relating response latency to degree of rotation was computed. The slope of this function was steeper for women than for men. Further, the distribution of slopes was more variable among women, with approximately 30% falling outside the range of distribution for men. Women and men were quite similar in the accuracy of their judgments, the intercepts of the latency functions, and the precision with which the linear function characterized the latency data. It is suggested that the sex difference in the slope of the rotation function may reflect differences in strategies of mental rotation.     

Searching for correlates of spatial ability

A brief questionnaire about sense of direction and mechanical experience correlated with Mental Rotation scores. Several new, experimental measures thought to be related to spatial ability did not in fact correlate with Mental Rotation scores.     

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.     

Supporting collaboration in virtual learning environments.

Early research argued that computer-mediated communication (CMC) had a number of advantages over existing communication media for supporting collaboration. However, a number of papers emerged that began to raise doubts about this positive view. These papers reported difficulties using CMC to support collaboration. Several systems are reported in this special issue that try to overcome these difficulties, either by changing the communication tools or by developing sound social spaces. These systems are important because the right tools and environment are essential; however, recent research suggests that we need to do more than this, because students do not know how to collaborate effectively and they need to develop these skills to use the tools productively. Other papers in this Special Issue suggest ways this might be achieved.     

Assessing human reorientation ability inside virtual reality environments: the effects of retention interval and landmark characteristics

The purpose of the present study was to assess the navigational behaviour of adult humans following a disorientation procedure that perturbed their egocentric frame of reference. The assessment was carried out in a virtual reality (VR) environment by manipulating the disorientation procedure, the retention interval, the relative positions of target and landmark. The results of experiment I demonstrated that adding a physical rotation to a virtual disorientation procedure did not yield an additional decrease in searching performance. The results of experiment II showed that shortening the delay between study and test phase decreased the errors more markedly for geometric than landmark ones. An orientation specificity effect due to the manipulation of the relative position between target and landmark was discussed across the experiments. In conclusion, VR seemed to be a valuable method for studying human reorientation. Moreover, the virtual experimental setting involved here promoted knowledge of the relationship between working memory and spatial reorientation paradigm.     

Route and survey processing of topographical memory during navigation

We investigated the characteristics of route and survey processing of a unique complex virtual environment both at the behavioral and brain levels. Prior to fMRI scanning, participants were trained to follow a route and to learn the spatial relationships between several places, acquiring both route and survey knowledge from a ground-level perspective. During scanning, snapshots of the environment were presented, and participants were required to either indicate the direction to take to follow the route (route task), or to locate unseen targets (survey task). Data suggest that route and survey processing are mainly supported by a common occipito-fronto-parieto-temporal neural network. Our results are consistent with those gathered in studies concerning the neural bases of route versus survey knowledge acquired either from different perspectives or in different environments. However, rather than arguing for a clear distinction between route and survey processing, “mixed” strategies are likely to be involved when both types of encoding take place in the same environment.     

Sex differences in spatial ability and spatial activities

Explanations of sex-related differences in spatial ability emphasizing the role of sex-differentiated experience have not been supported by direct measurement of spatial activities during adolescence, the period when these differences seem to increase. The present research involved development of a scale to measure the spatial experience of adolescents and adults. In Study 1, a list, as complete as possible of adolescent activities was compiled and given to undergraduate judges for ratings of involvement of spatial skills and sex-typing. Judges also indicated whether they had participated in each activity. Activities considered spatial by 75% or more of the judges were used to develop a spatial experience questionnaire. Judgments of the spatial nature of tasks were positively correlated with judged masculinity and with greater male than female participation. In Study 2, participation in spatial activities by undergraduates was correlated with spatial ability as measured by the Differential Aptitude Test. The activity questionnaire should prove useful in studying the development of spatial ability in adolescents and adults.     

Simultaneous spatial updating in nested environments

When one moves, the spatial relationship between oneself and the entire world changes. Spatial updating refers to the cognitive process that computes these relationships as one moves. In two experiments, we tested whether spatial updating occurs automatically for multiple environments simultaneously. Participants turned relative to either a room or the surrounding campus buildings and then pointed to targets in both the environment in which they turned (updated environment) and the other environment (nonupdated environment). The participants automatically updated the room targets when they moved relative to the campus, but they did not update the campus targets when they moved relative to the room. Thus, automatic spatial updating depends on the nature of the environment. Implications for theories of spatial learning and the structure of human spatial representations are discussed.     

Empirical evaluation of virtual environment technology as an experimental tool in developmental spatial cognition research

The study compared developmental aspects of spatial knowledge acquisition in a real and a virtual large-scale environment according to the classical study of Cohen and Schuepfer (1980 Cohen, R. and Schuepfer, T. 1980. The representation of landmarks and routes. Child Development, 51: 1065–1071. [Crossref], [Web of Science ®] , [Google Scholar]) with 40 younger children (7–8 years old), 40 older children (11–12 years old), and 40 adults. All participants learned the correct route through a maze, recalled the inherent landmarks, and drew a map of the maze. The results revealed equivalent age effects for these tasks in the real and the virtual world. In both conditions younger children needed more trials to learn the route and showed less configurational knowledge than older children and adults. Age group performance on landmark recollection did not differ in either the virtual or the real world maze. Except for the map drawing task performance was always worse in the virtual world condition. Because the developmental process was comparable in real and virtual environments, the results support the use of virtual environments for the research on developmental aspects of spatial knowledge.     

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.     

Spatial updating in superimposed real and virtual environments

Wang (2004) showed that people do not always simultaneously update their relationships to real and imagined environments in a dual-environment situation. Employing the same paradigm, we examined whether spatial updating operates on virtual reality as it does on a real or fictitious environment. Participants learned target locations in a real room and a virtual kitchen. Then they turned to face targets either in the room or in the kitchen, while blindfolded, and pointed to the targets before and after turning. Participants kept track of their orientation in both environments equally efficiently, regardless of explicit instructions. In contrast, when the real environment was described verbally but not directly perceived, participants automatically updated the virtual kitchen but not the room. These results suggest that people automatically update a virtual environment as they do a real one when the two environments are superimposed. The automaticity of spatial updating is discussed.