Immersion and the illusion of presence in virtual reality

This commentary briefly reviews the history of virtual reality and its use for psychology research, and clarifies the concepts of immersion and the illusion of presence.     

Affective interactions using virtual reality: the link between presence and emotions.

Many studies showed the ability of movies and imagery techniques to elicit emotions. Nevertheless, it is less clear how to manipulate the content of interactive media to induce specific emotional responses. In particular, this is true for the emerging medium virtual reality (VR), whose main feature is the ability to induce a feeling of "presence" in the computer-generated world experienced by the user. The main goal of this study was to analyze the possible use of VR as an affective medium. Within this general goal, the study also analyzed the relationship between presence and emotions. The results confirmed the efficacy of VR as affective medium: the interaction with "anxious" and "relaxing" virtual environments produced anxiety and relaxation. The data also showed a circular interaction between presence and emotions: on one side, the feeling of presence was greater in the "emotional" environments; on the other side, the emotional state was influenced by the level of presence. The significance of these results for the assessment of affective interaction is discussed.     

计算机虚拟技术训练辅助盲人构建空间表征之研究

摘要 由于视觉经验的缺乏,盲人的空间认知存在一定的缺陷,尤其表现在对现实环境的空间布局认识存在困难。本研究欲探究计算机虚拟技术手段辅助盲人建构表征的成效,并在此基础上探究盲人定向行走的效果。本研究是一个现场实验,采用随机分配的方式将全盲被试分为三组,之后让被试接受三种不同的实验处理,即计算机虚拟技术、触觉地图和人导处理,最后接受空间任务测试,测试不仅考察被试对环境空间布局的认识,而且还测量了被试在现实环境的行走探路效率。结果发现,虚拟技术组的被试不仅能够对整个实验环境形成清晰整体的认识,而且还能借助形成的空间表征在测验场地有效地实施定向行走。从研究结果得知,计算机虚拟技术这一手段对应用于改善盲人空间表征系统及提高盲人定向行走训练效率具有一定的积极意义。     

Treatment of acrophobia in virtual reality: the role of immersion and presence

In this study the effects of virtual reality exposure therapy (VRET) were investigated in patients with acrophobia. Feelings of presence in VRET were systematically varied by using either a head-mounted display (HMD) (low presence) or a computer automatic virtual environment (CAVE) (high presence). VRET in general was found to be more effective than no treatment. No differences were found in effectiveness between VRET using an HMD or CAVE. Results were maintained at 6 months follow-up. Results of VRET were comparable with those of exposure in vivo (Cyberpsychology and Behavior 4 (2001) 335). In treatment completers no relationship was found between presence and anxiety. Early drop-outs experienced less acrophobic complaints and psychopathology in general at pre-test. They also experienced less presence and anxiety in the virtual environment used in session one as compared to patients that completed VRET.     

Using a virtual reality system to study balance and walking in a virtual outdoor environment: a pilot study.

Falls and fall-related injuries are a major problem for elderly persons. Most falls occur during walking and turning, and the risk of falling increases when attention is diverted to something besides walking. It is often difficult to standardize methods for testing balance and fall tendency in a clinically relevant setting. We describe the development of a system using a virtual environment (VE) to assess how attention demanding and unexpected events influence a person's capacity to control balance and movement. The hardware in the system consists of a head-mounted display (HMD), a magnetic tracker system, and two SGI computers. The software consists of the image generation of the VE and the management and visualization of motion tracking data. In a preliminary pilot study eight subjects (age 23-80) participated. Each subject walked on a normal floor and was visually presented a familiar outdoor environment in the HMD. They were exposed to different unexpected events, such as a virtual snowfall and tilting of the VE. Disturbances of balance and walking patterns such as changes in speed, stride length and balance reactions like slipping were observed. Two subjects experienced symptoms of cyber sickness with a SSQ score above 25 points. Walking with sensors only did not affect walking time, but in VE the subjects generally walked more slowly. Virtual tilting of the environment had an impact on balance performance during walking. This effect was not observed while the test subjects were walking in a virtual snowfall. The model needs further development but may hold a potential for clinical use.     

Development of allocentric spatial recall from new viewpoints in virtual reality

Using landmarks and other scene features to recall locations from new viewpoints is a critical skill in spatial cognition. In an immersive virtual reality task, we asked children 3.5–4.5 years old to remember the location of a target using various cues. On some trials they could use information from their own self‐motion. On some trials they could use a view match. In the very hardest kind of trial, they were ‘teleported’ to a new viewpoint and could only use an allocentric spatial representation. This approach provides a strict test for allocentric coding (without either a matching viewpoint or self‐motion information) while avoiding additional task demands in previous studies (it does not require them to deal with a small table‐top environment or to manage stronger cue conflicts). Both the younger and older groups were able to point back at the target location better than chance when they could use view matching and/or self‐motion, but allocentric recall was only seen in the older group (4.0–4.5). In addition, we only obtained evidence for a specific kind of allocentric recall in the older group: they tracked one major axis of the space significantly above chance, r(158) = .28, but not the other, r(158) = ?.01. We conclude that there is a major qualitative change in coding for spatial recall around the fourth birthday, potentially followed by further development towards fully flexible recall from new viewpoints.     

Reaching within video-capture virtual reality: using virtual reality as a motor control paradigm.

We have developed a virtual reality (VR) system that integrates a three-dimensional tracking device with a video-capture VR platform to record upper limb movements. The influence of target velocity on planning and execution of reaching movements was studied in five healthy subjects. Our initial results suggest that a target's velocity is considered when planning an interceptive action and that a hand reaching toward a moving virtual target is controlled in a similar way to how it is in the real visual environment.     

Training cognitive skills in virtual reality: measuring performance.

Across a variety of operational environments, virtual reality (VR) is being increasingly used as a means of simulating hazardous work conditions in order to allow trainees to practice advanced cognitive skills such as problem-solving and decision-making. Replicating dangerous conditions particularly involving heavy machinery in the real world can be dangerous and costly. The use of VR is therefore appealing across many industries such as aviation, mining, and rail. However, while the number of training prototypes increase less focus is being given to appropriate evaluation of the training provided via this technology. Increasing skills acquisition and performance does not depend solely on the appropriate design of simulation training. Of equal importance are strong performance measures which can ultimately feedback on the success or otherwise of training and highlight any deficits to guide ongoing improvements. To ensure cognitive skills acquired in a virtual training environment (VTE) are transferable to the real world, training objectives need to be tied directly to realistic scenario events which in turn are directly linked to measures of specific required behaviors.     

The Rutgers Arm, a rehabilitation system in virtual reality: a pilot study.

Stroke is one of the leading causes of death and disability worldwide. Its prevalence calls for innovative rehabilitation methods. The Rutgers Arm is a novel upper extremity rehabilitation system consisting of a low-friction table, three-dimensional (3D) tracker, custom forearm support, PC workstation, library of Java 3D virtual reality (VR) exercises, clinical database module, and a tele-rehabilitation extension. The system was tested on a chronic stroke subject, under local and tele-rehabilitation conditions, over 5 weeks of training. Results show improvements in arm motor control and shoulder range of motion, corresponding to improved Fugl-Meyer test scores. Exercise duration, level of difficulty, and patient motivation were maintained under tele-rehabilitaion. A 1-week retention trial showed that gains were maintained.     

Neural correlates of action observation and execution in 14-month-old infants: an event-related EEG desynchronization study

There is increasing interest in neurobiological methods for investigating the shared representation of action perception and production in early development. We explored the extent and regional specificity of EEG desynchronization in the infant alpha frequency range (6-9 Hz) during action observation and execution in 14-month-old infants. Desynchronization during execution was restricted to central electrode sites, while action observation was associated with a broader desynchronization across frontal, central, and parietal regions. The finding of regional specificity in the overlap between EEG responses to action execution and observation suggests that the rhythm seen in the 6-9 Hz range over central sites in infancy shares certain properties with the adult mu rhythm. The magnitude of EEG desynchronization to action perception and production appears to be smaller for infants than for adults and older children, suggesting developmental change in this measure.     

Simulation and virtual reality in medical education and therapy: a protocol.

Continuing medical education has historically been provided primarily by didactic lectures, though adult learners prefer experiential or self-directed learning. Young physicians have extensive experience with computer-based or "video" games, priming them for medical education--and treating their patients--via new technologies. We report our use of standardized patients (SPs) to educate physicians on the diagnosis and treatment of biological and chemical warfare agent exposure. We trained professional actors to serve as SPs representing exposure to biological agents such as anthrax and smallpox. We rotated workshop participants through teaching stations to interview, examine, diagnose and treat SPs. We also trained SPs to simulate a chemical mass casualty (MASCAL) incident. Workshop participants worked together to treat MASCAL victims, followed by discussion of key teaching points. More recently, we developed computer-based simulation (CBS) modules of patients exposed to biological agents. We compare the strengths and weaknesses of CBS vs. live SPs. Finally, we detail plans for a randomized controlled trial to assess the efficacy of virtual reality (VR) exposure therapy compared to pharmacotherapy for post-traumatic stress disorder (PTSD). PTSD is associated with significant disability and healthcare costs, which may be ameliorated by the identification of more effective therapy.     

The influence of action on episodic memory: A virtual reality study

A range of empirical findings suggest that active learning is important for memory. However, few studies have focused on the mechanisms underlying this enactment effect in episodic memory using complex environments. Research using virtual reality has yielded inconsistent results. We postulated that the effect of action depends on the degree of interaction with the environment and freedom in the planning of an itinerary. To test these hypotheses, we disentangled the interaction and planning components of action to investigate whether each enhances factual and spatial memory. Seventy-two participants (36 male and 36 female) explored a virtual town in one of three experimental conditions: (a) a passive condition where participants were immersed as passenger of the car (no interaction, no planning); (b) a planning-only condition (the subject chose the itinerary but did not drive the car); (c) an interaction-only condition (the subject drove the car but the itinerary was fixed). We found that itinerary choice and motor control both enhanced spatial memory, while factual memory was impaired by online motor control. The role of action in memory is discussed.     

Age and active navigation effects on episodic memory: A virtual reality study

We investigated the navigation‐related age effects on learning, proactive interference semantic clustering, recognition hits, and false recognitions in a naturalistic situation using a virtual apartment‐based task. We also examined the neuropsychological correlates (executive functioning [EF] and episodic memory) of navigation‐related age effects on memory. Younger and older adults either actively navigated or passively followed the computer‐guided tour of an apartment. The results indicated that active navigation increased recognition hits compared with passive navigation, but it did not influence other memory measures (learning, proactive interference, and semantic clustering) to a similar extent in either age group. Furthermore, active navigation helped to reduce false recognitions in younger adults but increased those made by older adults. This differential effect of active navigation for younger and older adults was accounted for by EF score. Like for the subject‐performed task effects, the effects from the navigation manipulation were well accounted for by item‐specific/relational processing distinction, and they were also consistent with a source monitoring deficit in older adults.     

Depth perception in virtual reality: distance estimations in peri- and extrapersonal space.

The present study investigated depth perception in virtual environments. Twenty-three participants verbally estimated ten distances between 40 cm and 500 cm in three different virtual environments in two conditions: (1) only one target was presented or (2) ten targets were presented at the same time. Additionally, the presence of a metric aid was varied. A questionnaire assessed subjective ratings about physical complaints (e.g., headache), the experience in the virtual world (e.g., presence), and the experiment itself (self-evaluation of the estimations). Results show that participants underestimate the virtual distances but are able to perceive the distances in the right metric order even when only very simple virtual environments are presented. Furthermore, interindividual differences and intraindividual stabilities can be found among participants, and neither the three different virtual environments nor the metric aid improved depth estimations. Estimation performance is better in peripersonal than in extrapersonal space. In contrast, subjective ratings provide a preferred space: a closed room with visible floor, ceiling, and walls.     

Application of virtual reality graphics in assessment of concussion.

Abnormal balance in individuals suffering from traumatic brain injury (TBI) has been documented in numerous recent studies. However, specific mechanisms causing balance deficits have not been systematically examined. This paper demonstrated the destabilizing effect of visual field motion, induced by virtual reality graphics in concussed individuals but not in normal controls. Fifty five student-athletes at risk for concussion participated in this study prior to injury and 10 of these subjects who suffered MTBI were tested again on day 3, day 10, and day 30 after the incident. Postural responses to visual field motion were recorded using a virtual reality (VR) environment in conjunction with balance (AMTI force plate) and motion tracking (Flock of Birds) technologies. Two experimental conditions were introduced where subjects passively viewed VR scenes or actively manipulated the visual field motion. Long-lasting destabilizing effects of visual field motion were revealed, although subjects were asymptomatic when standard balance tests were introduced. The findings demonstrate that advanced VR technology may detect residual symptoms of concussion at least 30 days post-injury.     

The effects of the presence of others during a rowing exercise in a virtual reality environment

ObjectivesThe aim of the study was to test the performance, motivational, and affective impact of aerobic exercise within an immersive virtual reality environment experienced alone or with another individual.DesignSixty female participants aged 18–30 years were assigned to one of three conditions: no virtual reality (NVR), individual virtual reality (IVR), or companion virtual reality (CVR).MethodParticipants completed 9 min of self-paced rowing on an ergometer without any visual input or performance feedback (NVR), individually within a virtual reality environment (IVR), or within a virtual reality environment that included a companion depicted as an avatar (CVR).ResultsThe two virtual reality groups rowed a further distance and at a higher power output than the NVR group. Furthermore, the CVR group outperformed the IVR group in distance and had a higher heart rate. Participants in the virtual reality groups did not perceive themselves to be exerting more physical effort and rated the task as more enjoyable than participants in the NVR group.ConclusionsVirtual reality improves performance and the affective response to aerobic exercise, and performance effects are further enhanced by the presence of others in the virtual environment.     

An exploratory investigation of shopper behaviour in an immersive virtual reality store

Shopper research has long been undertaken with physical simulated stores and desktop‐operated virtual stores. However, recent developments in motion‐tracked virtual reality offer a range of new possibilities for research using immersive walk‐around virtual simulated stores. To date, there is little knowledge published on the authenticity of shopper behaviour in such immersive virtual environments. The present study therefore reports exploratory results from 153 multicategory shopping trips conducted in an immersive virtual convenience store. Observed shopper metrics and theoretical effects are compared with equivalent data obtained from published sources and found to be consistent across all measures. Specifically, shoppers purchase a plausible share of private label brands, more private label brands in lower consumption pleasure product categories, more products from higher compared with lower shelf positions, make a plausible proportion of impulsive purchases, and spend less time inspecting familiar versus unfamiliar brands. Further, time in‐store, total spending, and product handling time are higher for women than for men. These exploratory findings show that participants continue to exhibit realistic shopper behaviours in an immersive virtual simulated store. Such stores are therefore a cost‐effective alternative to other methods for measuring consumer behaviour. They offer significant potential for innovative experimental designs in consumer research, as well as potential for future use as a digital shopping channel.     

The study of locomotor pointing in virtual reality: The validation of a test set-up

The goal of this experiment was to validate an experimental set-up for studying locomotor pointing. The specific and also original element of this set-up was the interactive nature of virtual reality and movement production. This interaction was achieved through the coupling of a treadmill and a Silicon Graphics system. This latter system generated on a screen (3 × 2.3 m) an environmental array that moved according to the action produced by subjects on a treadmill. The task was to place either foot on a spatial target that appeared on the floor in front of the subject’s displacement trajectory. We analyzed the step length patterns of subjects approaching these targets, along with the current target-subject relationship. The results are in agreement with aperception-action coupling type of control mechanism that operates continuously as the subject approaches the desired target. Apparently, these findings mirror observations of real-life locomotion, indicating that the present set-up provides a valid and useful tool for examining human locomotion.     

The impact of state and dispositional mindfulness on prospective memory: A virtual reality study

Prospective memory (PM) consists of remembering to perform an action that was previously planned. The recovery and execution of these actions require attentional resources. Mindfulness, as a state or a dispositional trait, has been associated with better attentional abilities while mind wandering is linked with attentional failures. In this study, we investigated the impact of mindfulness on PM. Eighty participants learned 15 cue-action associations. They were, then, asked to recall the actions at certain moments (time-based items) or places (event-based items) during a walk in a virtual town. Before the PM task, participants were randomly assigned to a mindfulness or mind wandering (control condition) session. Dispositional mindfulness was measured via the Five Facets Mindfulness Questionnaire (FFMQ). Although considered as two opposite states, we did not report any difference between the two groups on PM abilities. Nevertheless, the natural tendency to describe one's own sensations (the Describing facet of the FFMQ) predicted time-based performance in both groups. We discuss different hypotheses to explain this finding in light of recent findings on the impact of mind wandering on future oriented cognition. Our main observation is a positive link between the Describing facet and time-based PM performances. We propose that this link could be due to the common association of this mindfulness facets and PM with attentional and interoceptive abilities. Additional studies are needed to explore this hypothesis.