Temporal dynamics in the relation between presence and fear in virtual reality

[VR-supported therapy for anxiety and posttraumatic stress disorder: current possibilities and limitations]

BACKGROUND

Virtual reality (VR) is increasingly used in psychotherapy, and the speed of development of therapeutic VR tools is continuously increasing.

OBJECTIVE

This narrative review provides an overview of the state of the art regarding VR applications for psychotherapy.

MATERIAL AND METHODS

The current state of VR therapy research for anxiety disorders and posttraumatic stress disorder (PTSD) is summarized. The focus lies on VR exposure therapy. Current developments in the field are outlined.

RESULTS

For anxiety disorders, especially phobic disorders, there are already positive recommendations in the current German S3 guidelines. For PTSD, the development of VR therapy tools is still in a relatively early stage.

CONCLUSION

The development of mobile cost-effective VR solutions in recent years has enabled entirely new applications for VR. The empirical challenges of these new developments are considerable. Nevertheless, the chances for an improvement of psychotherapeutic routine care are good.

The underwood project: A virtual environment for eliciting ambiguous threat

Threatening environments can be unpredictable in many different ways. The nature of threats, their timing, and their locations in a scene can all be uncertain, even when one is acutely aware of being at risk. Prior research demonstrates that both temporal unpredictability and spatial uncertainty of threats elicit a distinctly anxious psychological response. In the paradigm presented here, we further explore other facets of ambiguous threat via an environment in which there are no concrete threats, predictable or otherwise, but which nevertheless elicits a building sense of danger. By incorporating both psychological research and principles of emotional game design, we constructed this world and then tested its effects in three studies. In line with our goals, participants experienced the environment as creepy and unpredictable. Their subjective and physiological response to the world rose and fell in line with the presentation of ambiguously threatening ambient cues. Exploratory analyses further suggest that this ambiguously threatening experience influenced memory for the virtual world and its underlying narrative. Together the data demonstrate that naturalistic virtual worlds can effectively elicit a multifaceted experience of ambiguous threat with subjective and cognitive consequences.

Virtual fashion experiences in virtual reality fashion show spaces

Introduction

Virtual reality (VR) provides a new fashion space and fashion experience. This study focuses on immersive VR and fashion shows to empirically explore the VR fashion space and fashion experience. Insights specific to fashion have not been presented in as much depth in the literature; thus, the current findings are particularly valuable and insightful.

Methods

This study employed three immersive VR (IVR) fashion show stimuli and in-depth interviews according to a semi-structured questionnaire. Collected data were analyzed based on the concept of VR space and VR experience derived through literature research.

Results

The VR fashion space was divided into three types and VR experiences of cognitive presence, sensible immersion, emotional immersion, and aesthetic interaction were derived accordingly. First, the physical representation of a fashion show induced a cognitive and emotional sense of presence, in which users felt as though they had moved to the same time and place as those at the fashion show. Second, participants experienced cognitive confusion owing to the differences with a priori experiences in the fashion show space (i.e., reality and imagination coexist). Third, participants transcended the limitations of physical reality while in the fashion show space of pataphysics (which was realized with human imagination), and they moved beyond the stage of confusion that is experienced while facing realistic objects to connect to creative inspiration.

Discussion

The difference in the properties of VR space may be associated with distinct VR fashion experiences. The findings suggest that (1) a priori elements such as sociocultural contexts and personal experiences differ in the experiential dimension of virtual space, (2) the VR fashion show space induces a psychological experience between brand and consumer, and (3) creative inspiration and exploratory play can be greatly induced in a user if the immersive fashion space is further from the original source.

The Auxiliary Role of Virtual Reality in Enhancing the Effects of Disaster News on Empathy and Fear: The Mediating Role of Presence

This study conducted a two-condition between-subjects laboratory experiment (N = 147) to examine the effects of textual disaster news combined with a 360° video in different modes (virtual reality [VR] vs. two dimensional screen) on cognitive/affective empathy and fear. Additionally, the mediating role of presence (social and spatial presence) was considered. Results indicated that the news article presented through an immersive VR mode directly led to greater levels of presence and cognitive empathy but not affective empathy and fear. The effects on social presence further resulted in greater cognitive and affective empathy, not fear. Meanwhile, spatial presence enhanced by VR led to greater levels of emotions (affective empathy and fear) but not cognitive empathy. These findings suggest the dynamic mechanisms of how an immersive VR modality can function as a complementary tool for traditional news to improve audience engagement, which centers on emotion-related outcomes in tandem with cognitive responses.

Review of Psychophysiological and Psychotherapeutic Studies of Stress Using Virtual Reality Technologies

This review addresses the use of virtual reality technologies in the psychophysiology and psychotherapy of stress. Studies using virtual reality both to introduce subjects into a state of stress and to help reduce stress reactions are reviewed. Methods developed for treating patients suffering from stress-related disorders (in particular, PTSD and phobias) are described. In many cases, reductions in stress reactions with the help of virtual reality systems are achieved not only at the self-report (experiential) level, but also at the level of central and peripheral nervous system measures. This allows virtual reality to be regarded as a modern, inexpensive, and effective method, firstly, for introducing subjects into a state of stress with the aim of testing various hypotheses in psychophysiology and, secondly, to reduce stress reactions.

Multimodal Assessment of Changes in Physiological Indicators when Presenting a Video Fragment on Screen (2D) versus a VR (3D) Environment

The increasing role of virtual environments in society, especially in the context of the pandemic and evolving metaverse technologies, requires a closer study of the physiological state of humans using virtual reality (VR) for entertainment, work, or learning. Despite the fact that many physiological reactions to the content presented in various modalities under VR conditions have already been described, often these studies do not reflect the full range of changes in the physiological reactions that occur to a person during their immersion in the virtual world. This study was designed to find and compare the most sensitive physiological indicators that change when viewing an emotionally intense video fragment in standard format on screen and in virtual reality conditions (in a VR helmet). The research methodology involved randomly presenting a group of subjects with visual content-a short video clip-first on screen (2D) and then in a virtual reality helmet (3D). A special feature of this study is the use of multimodal physiological state assessment throughout the content presentation, in conjunction with psychological testing of the study participants before and after the start of the study. It has been discovered that the most informative physiological indicators reflecting the subjects' condition under virtual reality conditions were changes in theta rhythm amplitude, skin conductance, standard deviation of normal RR-intervals (SDRR), and changes in photoplethysmogram (PPG). The study results suggest that in the process of immersion in a virtual environment, the participants develop a complex functional state, different from the state when watching on screen, which is characterised by the restructuring of autonomic regulation and activation of emotion structures of the brain.

Virtual Reality for Aggression Assessment: The Development and Preliminary Results of Two Virtual Reality Tasks to Assess Reactive and Proactive Aggression in Males

Validly measuring aggression is challenging because self-reports are plagued with biased answer tendencies and behavioral measures with ethical concerns and low ecological validity. The current study, therefore, introduces a novel virtual reality (VR) aggression assessment tool, differentially assessing reactive and proactive aggression. Two VR tasks were developed, one in an alley environment (N = 24, all male, Mage = 23.88, 83.3% students) and an improved second one in a bar (N = 50, all male, Mage = 22.54, 90% students). In this bar VR task, participants were randomly assigned to either the reactive condition where they were triggered by a cheating and insulting dart-player or to the proactive condition where they could earn extra money by aggressing. Participants' level of self-reported aggression and psychopathy was assessed, after which they engaged in either the reactive or proactive VR task. Changes in affect and blood pressure were also measured. Aggression in the reactive VR task was evidenced to mostly display convergent validity because it positively correlated with self-reported aggression and total and fearless dominance factor scores of psychopathy, and there was a trend relationship with increased systolic blood pressure. The validity of the proactive aggression variant of our VR bar paradigm received less support, and needs more refinement. It can be concluded that VR is a potentially promising tool to experimentally induce and assess (reactive) aggression, which has the potential to provide aggression researchers and clinicians with a realistic and modifiable aggression assessment environment.

Self-imagery and advertising effectiveness: the role of sense of presence

The purpose of this study was to assess whether self-imagery is more effective than other-imagery, and if so, to investigate the mechanism of how self-imagery generates more increased positive responses from consumers. Furthermore, we explored the boundary conditions associated with reduced positive effects of self-imagery on consumer responses. The results of Experiment 1 suggest that self-imagery was more effective than other-imagery in generating a favorable attitude toward an advertisement and purchase intention, since it enhanced a sense of presence, and consequently, imagery engagement. However, based on the results of Experiment 2, when an advertisement evoked a sense of high-risk, self-imagery generated a less favorable attitude toward the advertisement than other-imagery due to the emotion of fear evoked by the advertisement.

Emotional arousal in 2D versus 3D virtual reality environments

Previous studies have suggested that virtual reality (VR) can elicit emotions in different visual modes using 2D or 3D headsets. However, the effects on emotional arousal by using these two visual modes have not been comprehensively investigated, and the underlying neural mechanisms are not yet clear. This paper presents a cognitive psychological experiment that was conducted to analyze how these two visual modes impact emotional arousal. Forty volunteers were recruited and were randomly assigned to two groups. They were asked to watch a series of positive, neutral and negative short VR videos in 2D and 3D. Multichannel electroencephalograms (EEG) and skin conductance responses (SCR) were recorded simultaneously during their participation. The results indicated that emotional stimulation was more intense in the 3D environment due to the improved perception of the environment; greater emotional arousal was generated; and higher beta (21-30 Hz) EEG power was identified in 3D than in 2D. We also found that both hemispheres were involved in stereo vision processing and that brain lateralization existed in the processing.

Gamification and Hazard Communication in Virtual Reality: A Qualitative Study

An effective warning attracts attention, elicits knowledge, and enables compliance behavior. Game mechanics, which are directly linked to human desires, stand out as training, evaluation, and improvement tools. Immersive virtual reality (VR) facilitates training without risk to participants, evaluates the impact of an incorrect action/decision, and creates a smart training environment. The present study analyzes the user experience in a gamified virtual environment of risks using the HTC Vive head-mounted display. The game was developed in the Unreal game engine and consisted of a walk-through maze composed of evident dangers and different signaling variables while user action data were recorded. To demonstrate which aspects provide better interaction, experience, perception and memory, three different warning configurations (dynamic, static and smart) and two different levels of danger (low and high) were presented. To properly assess the impact of the experience, we conducted a survey about personality and knowledge before and after using the game. We proceeded with the qualitative approach by using questions in a bipolar laddering assessment that was compared with the recorded data during the game. The findings indicate that when users are engaged in VR, they tend to test the consequences of their actions rather than maintaining safety. The results also reveal that textual signal variables are not accessed when users are faced with the stress factor of time. Progress is needed in implementing new technologies for warnings and advance notifications to improve the evaluation of human behavior in virtual environments of high-risk surroundings.

Development of a Virtual Ecological Environment for Learning the Taipei Tree Frog

The learning objectives of environmental education emphasize investigation in real life to enhance students’ skills and experiences in solving practical problems. This study used the virtual reality (VR) technology to develop a virtual ecological environment for learning about the Taipei tree frog, supported by situated learning and game-based learning design to enhance students’ learning interest and motivation. Users can wear the head-mounted display (HMD) to explore the virtual environment for learning the Taipei tree frog’s ecological behavior, such as foraging and mating as well as its habitats and predators. A teaching experiment was conducted to investigate students’ learning effectiveness and the senses of presence and anxiety after using the virtual ecological environment. The experimental group (wearing the HMD) contained 40 students, the control group (using the desktop VR) contained 40 students, and both groups were used as samples to learn about the Taipei tree frog. The results indicated that using HMD VR and desktop VR could both enhance learning achievements, but the learning effectiveness of the former was significantly higher than that of the latter. The levels of anxiety for both groups were about the same, but the level of presence for the experimental group was higher than that of the control group because the HMD VR provided a more immersive experience than the desktop VR. The virtual ecological environment can save the time and effort of travelling to the natural habitat for observing the Taipei tree frog, and the design of role-playing game (RPG) can enhance learners’ interest and motivation. Therefore, it is a useful tool for promoting environmental education.

Personalized Virtual Reality Human-Computer Interaction for Psychiatric and Neurological Illnesses: A Dynamically Adaptive Virtual Reality Environment That Changes According to Real-Time Feedback From Electrophysiological Signal Responses

Virtual reality (VR) constitutes an alternative, effective, and increasingly utilized treatment option for people suffering from psychiatric and neurological illnesses. However, the currently available VR simulations provide a predetermined simulative framework that does not take into account the unique personality traits of each individual; this could result in inaccurate, extreme, or unpredictable responses driven by patients who may be overly exposed and in an abrupt manner to the predetermined stimuli, or result in indifferent, almost non-existing, reactions when the stimuli do not affect the patients adequately and thus stronger stimuli are recommended. In this study, we present a VR system that can recognize the individual differences and readjust the VR scenarios during the simulation according to the treatment aims. To investigate and present this dynamically adaptive VR system we employ an Anxiety Disorder condition as a case study, namely arachnophobia. This system consists of distinct anxiety states, aiming to dynamically modify the VR environment in such a way that it can keep the individual within a controlled, and appropriate for the therapy needs, anxiety state, which will be called "desired states" for the study. This happens by adjusting the VR stimulus, in real-time, according to the electrophysiological responses of each individual. These electrophysiological responses are collected by an external electrodermal activity biosensor that serves as a tracker of physiological changes. Thirty-six diagnosed arachnophobic individuals participated in a one-session trial. Participants were divided into two groups, the Experimental Group which was exposed to the proposed real-time adaptive virtual simulation, and the Control Group which was exposed to a pre-recorded static virtual simulation as proposed in the literature. These results demonstrate the proposed system's ability to continuously construct an updated and adapted virtual environment that keeps the users within the appropriately chosen state (higher or lower intensity) for approximately twice the time compared to the pre-recorded static virtual simulation. Thus, such a system can increase the efficiency of VR stimulations for the treatment of central nervous system dysfunctions, as it provides numerically more controlled sessions without unexpected variations.

Immersive virtual environments and embodied agents for e-learning applications

Massive Open Online Courses are a dominant force in remote-learning yet suffer from persisting problems stemming from lack of commitment and low completion rates. In this initial study we investigate how the use of immersive virtual environments for Power-Point based informational learning may benefit learners and mimic traditional lectures successfully. We examine the role of embodied agent tutors which are frequently implemented within virtual learning environments. We find similar performance on a bespoke knowledge test and metrics for motivation, satisfaction, and engagement by learners in both real and virtual environments, regardless of embodied agent tutor presence. Our results raise questions regarding the viability of using virtual environments for remote-learning paradigms, and we emphasise the need for further investigation to inform the design of effective remote-learning applications.

Playing with fire. Understanding how experiencing a fire in an immersive virtual environment affects prevention behavior

A potentially effective way to influence people's fire prevention behavior is letting them experience a fire in an immersive virtual environment (IVE). We analyze the effects of experiencing a fire in an IVE (versus an information sheet) on psychological determinants of behavior-knowledge, vulnerability, severity, self-efficacy, and locus of control-based mainly on arguments from Protection Motivation Theory and the Health Belief Model. Crucial in our setup is that we also relate these determinants to actual prevention behavior. Results show that IVE has the hypothesized effects on vulnerability, severity, and self-efficacy, and an unexpected negative effect on knowledge. Only knowledge and vulnerability showed subsequent indirect effects on actual prevention behavior. There remains a direct positive effect of IVE on prevention behavior that cannot be explained by any of the determinants. Our results contradict the implicit assumption that an induced change in these psychological determinants by IVE, necessarily implies a change in behavior. A recommendation for research on the effects of IVE's is, whenever possible, to study the actual target behavior as well.

Virtual Reality for Anxiety Disorders: Rethinking a Field in Expansion

The principal aim to this chapter is to present the latest ideas in virtual reality (VR), some of which have already been applied to the field of anxiety disorders, and others are still pending to be materialized. More than 20 years ago, VR emerged as an exposure tool in order to provide patients and therapists with more appealing ways of delivering a technique that was undoubtedly effective but also rejected and thus underused. Throughout these years, many improvements were achieved. The first section of the chapter describes those improvements, both considering the research progresses and the applications in the real world. In a second part, our main interest is to expand the discussion of the new applications of VR beyond its already known role as an exposure tool. In particular, VR is enabling the materialization of numerous ideas that were previously confined to a merely philosophical discussion in the field of cognitive sciences. That is, VR has the enormous potential of providing feasible ways to explore nonclassical ways of cognition, such as embodied and situated information processing. Despite the fact that many of these developments are not fully developed, and not specifically designed for anxiety disorders, we want to introduce these new ideas in a context in which VR is experiencing an enormous transformation.

Virtual skills training: the role of presence and agency

Virtual reality (VR) simulations provide increased feelings of presence and agency that could allow increased skill improvement during VR training. Direct relationships between active agency in VR and skill improvement have previously not been investigated. This study examined the relationship between (a) presence and agency, and (b) presence and skills improvement, via active and passive VR simulations and through measuring real-world golf-putting skill. Participants (n = 23) completed baseline putting skill assessment before using an Oculus Rift VR head-mounted display to complete active (putting with a virtual golf club) and passive (watching a game of golf) VR simulations. Measures of presence and agency were administered after each simulation, followed by a final putting skill assessment. The active simulation induced higher feelings of general presence and agency. However, no relationship was identified between presence and either agency or skill improvement. No skill improvement was evident in either the active or passive simulations, potentially due to the short training period applied, as well as a lack of realism in the VR simulations inhibiting a transfer of skills to a real environment. These findings reinforce previous literature that shows active VR to increase feelings of presence and agency. This study generates a number of fruitful research questions about the relationship between presence and skills training.

A Sustainability Innovation Experiential Learning Model for Virtual Reality Chemistry Laboratory: An Empirical Study with PLS-SEM and IPMA

This study focuses on serious virtual reality games, and how users can increase their understanding of the sustainable innovation learning (SIL) model and their familiarity with sustainable development strategies. “Users” of serious games consists of all possible target groups that are interested in attaining knowledge of sustainability through the use of games that are designed for a purpose beyond entertainment, in this case, for sustainable education. This research investigates the sustainable innovation experiential learning model by using a virtual chemistry laboratory to affect academic achievement. A questionnaire was completed by students who had used the virtual lab, and structural equation modeling (SEM) was applied for analysis. Importance-performance matrix analysis (IPMA) was able to help expand the basic partial least square (PLS)-SEM result with the fraction. The results show that experiential learning significantly affects learning motivation and academic achievement. Cognitive load and self-efficacy significantly affect learning motivation. Involvement significantly affects academic achievement. The virtual chemistry laboratory significantly affects academic achievement. Students who used the sustainability innovation experiential learning model obtained a better understanding of the chemical concepts. Moreover, a virtual lab promotes students’ motivation in regard to chemistry.

Causal Interactive Links Between Presence and Fear in Virtual Reality Height Exposure

Virtual reality plays an increasingly important role in research and therapy of pathological fear. However, the mechanisms how virtual environments elicit and modify fear responses are not yet fully understood. Presence, a psychological construct referring to the ‘sense of being there’ in a virtual environment, is widely assumed to crucially influence the strength of the elicited fear responses, however, causality is still under debate. The present study is the first that experimentally manipulated both variables to unravel the causal link between presence and fear responses. Height-fearful participants (N = 49) were immersed into a virtual height situation and a neutral control situation (fear manipulation) with either high versus low sensory realism (presence manipulation). Ratings of presence and verbal and physiological (skin conductance, heart rate) fear responses were recorded. Results revealed an effect of the fear manipulation on presence, i.e., higher presence ratings in the height situation compared to the neutral control situation, but no effect of the presence manipulation on fear responses. However, the presence ratings during the first exposure to the high quality neutral environment were predictive of later fear responses in the height situation. Our findings support the hypothesis that experiencing emotional responses in a virtual environment leads to a stronger feeling of being there, i.e., increase presence. In contrast, the effects of presence on fear seem to be more complex: on the one hand, increased presence due to the quality of the virtual environment did not influence fear; on the other hand, presence variability that likely stemmed from differences in user characteristics did predict later fear responses. These findings underscore the importance of user characteristics in the emergence of presence.

Height Simulation in a Virtual Reality CAVE System: Validity of Fear Responses and Effects of an Immersion Manipulation

Acrophobia is characterized by intense fear in height situations. Virtual reality (VR) can be used to trigger such phobic fear, and VR exposure therapy (VRET) has proven effective for treatment of phobias, although it remains important to further elucidate factors that modulate and mediate the fear responses triggered in VR. The present study assessed verbal and behavioral fear responses triggered by a height simulation in a 5-sided cave automatic virtual environment (CAVE) with visual and acoustic simulation and further investigated how fear responses are modulated by immersion, i.e., an additional wind simulation, and presence, i.e., the feeling to be present in the VE. Results revealed a high validity for the CAVE and VE in provoking height related self-reported fear and avoidance behavior in accordance with a trait measure of acrophobic fear. Increasing immersion significantly increased fear responses in high height anxious (HHA) participants, but did not affect presence. Nevertheless, presence was found to be an important predictor of fear responses. We conclude that a CAVE system can be used to elicit valid fear responses, which might be further enhanced by immersion manipulations independent from presence. These results may help to improve VRET efficacy and its transfer to real situations.

Recent Progress in Virtual Reality Exposure Therapy for Phobias: A Systematic Review

This review is designed to systematically examine the available evidence about virtual reality exposure therapy's (VRET) efficacy for phobias, critically describe some of the most important challenges in the field and discuss possible directions. Evidence reveals that virtual reality (VR) is an effective treatment for phobias and useful for studying specific issues, such as pharmacological compounds and behavioral manipulations, that can enhance treatment outcomes. In addition, some variables, such as sense of presence in virtual environments, have a significant influence on outcomes, but further research is needed to better understand their role in therapeutic outcomes. We conclude that VR is a useful tool to improve exposure therapy and it can be a good option to analyze the processes and mechanisms involved in exposure therapy and the ways this strategy can be enhanced. In the coming years, there will be a significant expansion of VR in routine practice in clinical contexts.

The Enactive Approach to Architectural Experience: A Neurophysiological Perspective on Embodiment, Motivation, and Affordances

Over the last few years, the efforts to reveal through neuroscientific lens the relations between the mind, body, and built environment have set a promising direction of using neuroscience for architecture. However, little has been achieved thus far in developing a systematic account that could be employed for interpreting current results and providing a consistent framework for subsequent scientific experimentation. In this context, the enactive perspective is proposed as a guide to studying architectural experience for two key reasons. Firstly, the enactive approach is specifically selected for its capacity to account for the profound connectedness of the organism and the world in an active and dynamic relationship, which is primarily shaped by the features of the body. Thus, particular emphasis is placed on the issues of embodiment and motivational factors as underlying constituents of the body-architecture interactions. Moreover, enactive understanding of the relational coupling between body schema and affordances of architectural spaces singles out the two-way bodily communication between architecture and its inhabitants, which can be also explored in immersive virtual reality settings. Secondly, enactivism has a strong foothold in phenomenological thinking that corresponds to the existing phenomenological discourse in architectural theory and qualitative design approaches. In this way, the enactive approach acknowledges the available common ground between neuroscience and architecture and thus allows a more accurate definition of investigative goals. Accordingly, the outlined model of architectural subject in enactive terms—that is, a model of a human being as embodied, enactive, and situated agent, is proposed as a basis of neuroscientific and phenomenological interpretation of architectural experience.

Representation of Patients' Hand Modulates Fear Reactions of Patients with Spider Phobia in Virtual Reality

Embodiment (i.e., the involvement of a bodily representation) is thought to be relevant in emotional experiences. Virtual reality (VR) is a capable means of activating phobic fear in patients. The representation of the patient's body (e.g., the right hand) in VR enhances immersion and increases presence, but its effect on phobic fear is still unknown. We analyzed the influence of the presentation of the participant's hand in VR on presence and fear responses in 32 women with spider phobia and 32 matched controls. Participants sat in front of a table with an acrylic glass container within reaching distance. During the experiment this setup was concealed by a head-mounted display (HMD). The VR scenario presented via HMD showed the same setup, i.e., a table with an acrylic glass container. Participants were randomly assigned to one of two experimental groups. In one group, fear responses were triggered by fear-relevant visual input in VR (virtual spider in the virtual acrylic glass container), while information about a real but unseen neutral control animal (living snake in the acrylic glass container) was given. The second group received fear-relevant information of the real but unseen situation (living spider in the acrylic glass container), but visual input was kept neutral VR (virtual snake in the virtual acrylic glass container). Participants were instructed to touch the acrylic glass container with their right hand in 20 consecutive trials. Visibility of the hand was varied randomly in a within-subjects design. We found for all participants that visibility of the participant's hand increased presence independently of the fear trigger. However, in patients, the influence of the virtual hand on fear depended on the fear trigger. When fear was triggered perceptually, i.e., by a virtual spider, the virtual hand increased fear. When fear was triggered by information about a real spider, the virtual hand had no effect on fear. Our results shed light on the significance of different fear triggers (visual, conceptual) in interaction with body representations.

Fear and physiological arousal during a virtual height challenge--effects in patients with acrophobia and healthy controls

Virtual reality (VR) exposure therapy is becoming increasingly established, but the mode of action is not well understood. One potential efficacy factor might be physiological arousal. To investigate arousal during VR exposure, we exposed 40 patients with acrophobia and 40 matched healthy controls to a VR height challenge and assessed subjective (fear ratings) and physiological (heart rate, skin conductance level, salivary cortisol) fear reactions. Patients experienced a significant increase of subjective fear, heart rate and skin conductance level. Unexpectedly, controls, who reported no subjective fear, also showed an increase in heart rate and skin conductance. There was no increase in salivary cortisol levels in either group. Physiological arousal in acrophobic patients, in contrast to subjective fear, might not be stronger than that of controls confronted with height cues in VR, indicating marked discordance across symptom domains. The lack of a cortisol response in a clearly stressful paradigm warrants further study.