Mechanisms of virtual reality exposure therapy: the role of the behavioral activation and behavioral inhibition systems

Postpartum Depression: A Clinical Review of Impact and Current Treatment Solutions

Depression during the first year postpartum (postpartum depression) impacts millions of women and their families worldwide. In this narrative review, we provide a summary of postpartum depression, examining the etiology and consequences, pharmacological and psychological treatments, and potential mechanisms of change and current barriers to care. Psychological treatments are effective and preferred by many perinatal patients over medications, but they often remain inaccessible. Key potential mechanisms underlying their effectiveness include treatment variables (e.g., dosage and therapeutic alliance) and patient behaviors (e.g., activation and avoidance and emotional regulation). Among pharmacological treatments, the selective serotonin reuptake inhibitor (SSRI) sertraline is generally the first-line antidepressant medication recommended to women in the postpartum period due to its minimal passage into breastmilk and the corresponding decades of safety data. Importantly, most antidepressant drugs are considered compatible with breastfeeding. Neurosteroids are emerging as an effective treatment for postpartum depression, although currently this treatment is not widely available. Barriers to widespread access to treatment include those that are systematic (e.g., lack of specialist providers), provider-driven (e.g., lack of flexibility in treatment delivery), and patient-driven (e.g., stigma and lack of time for treatment engagement). We propose virtual care, task-sharing to non-specialist treatment providers, and collaborative care models as potential solutions to enhance the reach and scalability of effective treatments to address the growing burden of postpartum depression worldwide and its negative impact on families and society.

Virtual reality in the diagnostic and therapy for mental disorders: A systematic review

BACKGROUND

Virtual reality (VR) technologies are playing an increasingly important role in the diagnostics and treatment of mental disorders.

OBJECTIVE

To systematically review the current evidence regarding the use of VR in the diagnostics and treatment of mental disorders.

DATA SOURCE

Systematic literature searches via PubMed (last literature update: 9^th of May 2022) were conducted for the following areas of psychopathology: Specific phobias, panic disorder and agoraphobia, social anxiety disorder, generalized anxiety disorder, posttraumatic stress disorder (PTSD), obsessive-compulsive disorder, eating disorders, dementia disorders, attention-deficit/hyperactivity disorder, depression, autism spectrum disorder, schizophrenia spectrum disorders, and addiction disorders.

ELIGIBILITY CRITERIA

To be eligible, studies had to be published in English, to be peer-reviewed, to report original research data, to be VR-related, and to deal with one of the above-mentioned areas of psychopathology.

STUDY EVALUATION

For each study included, various study characteristics (including interventions and conditions, comparators, major outcomes and study designs) were retrieved and a risk of bias score was calculated based on predefined study quality criteria.

RESULTS

Across all areas of psychopathology, k = 9315 studies were inspected, of which k = 721 studies met the eligibility criteria. From these studies, 43.97% were considered assessment-related, 55.48% therapy-related, and 0.55% were mixed. The highest research activity was found for VR exposure therapy in anxiety disorders, PTSD and addiction disorders, where the most convincing evidence was found, as well as for cognitive trainings in dementia and social skill trainings in autism spectrum disorder.

CONCLUSION

While VR exposure therapy will likely find its way successively into regular patient care, there are also many other promising approaches, but most are not yet mature enough for clinical application.

REVIEW REGISTRATION

PROSPERO register CRD42020188436.

FUNDING

The review was funded by budgets from the University of Bonn. No third party funding was involved.

Virtual reality and mental health in older adults: a systematic review

IMPORTANCE

Virtual reality (VR) is a promising tool with the potential to enhance care of cognitive and affective disorders in the aging population. VR has been implemented in clinical settings with adolescents and children; however, it has been less studied in the geriatric population.

OBJECTIVE

The objective of this study is to determine the existing levels of evidence for VR use in clinical settings and identify areas where more evidence may guide translation of existing VR interventions for older adults.

DESIGN AND MEASUREMENTS

We conducted a systematic review in PubMed and Web of Science in November 2019 for peer-reviewed journal articles on VR technology and its applications in older adults. We reviewed article content and extracted the number of study participants, study population, goal of the investigation, the level of evidence, and categorized articles based on the indication of the VR technology and the study population.

RESULTS

The database search yielded 1554 total results, and 55 articles were included in the final synthesis. The most represented study design was cross-sectional, and the most common study population was subjects with cognitive impairment. Articles fell into three categories for VR Indication: Testing, Training, and Screening. There was a wide variety of VR environments used across studies.

CONCLUSIONS

Existing evidence offers support for VR as a screening and training tool for cognitive impairment in older adults. VR-based tasks demonstrated validity comparable to some paper-based assessments of cognition, though more work is needed to refine diagnostic specificity. The variety of VR environments used shows a need for standardization before comparisons can be made across VR simulations. Future studies should address key issues such as usability, data privacy, and confidentiality. Since most literature was generated from high-income countries (HICs), it remains unclear how this may be translated to other parts of the world.

Targeted Memory Reactivation During REM Sleep in Patients With Social Anxiety Disorder

BACKGROUND

Social anxiety disorder (SAD) is characterized by a significant amount of fear when confronted to social situations. Exposure therapy, which is based on fear extinction, does not often lead to full remission. Here, based on evidence showing that rapid eye movement (REM) sleep promotes the consolidation of extinction memory, we used targeted memory reactivation (TMR) during REM sleep to enhance extinction learning in SAD.

METHODS

Forty-eight subjects with SAD were randomly assigned to two groups: control or TMR group. All patients had two successive exposure therapy sessions in a virtual reality (VR) environment, where they were asked to give a public talk in front of a virtual jury. At the end of each session, and only in the TMR group (N = 24), a sound was paired to the positive feedback phase of therapy (i.e., approval of their performance), which represented the memory to be strengthened during REM sleep. All participants slept at home with a wearable headband device which automatically identified sleep stages and administered the sound during REM sleep. Participants' anxiety level was assessed using measures of parasympathetic (root mean square of successive differences between normal heartbeats, RMSSD) and sympathetic (non-specific skin conductance responses, ns-SCRs) activity, and subjective measures (Subjective Units of Distress Scale, SUDS), during the preparation phase of their talks before (T1) and after (T2) one full-night's sleep and after 1 week at home (T3). Participants also filled in a dream diary.

RESULTS

We observed an effect of time on subjective measures of anxiety (SUDS). We did not find any difference in the anxiety levels of the two groups after 1 week of TMR at home. Importantly, the longer the total duration of REM sleep and the more stimulations the TMR group had at home, the less anxious (increased RMSSD) these participants were. Finally, fear in dreams correlated positively with ns-SCRs and SUDS at T3 in the TMR group.

CONCLUSION

TMR during REM sleep did not significantly modulate the beneficial effect of therapy on subjective anxiety. Yet, our results support that REM sleep can contribute to extinction processes and substantiate strong links between emotions in dreams and waking stress levels in these patients.

Physiological and self-reported arousal in virtual reality versus face-to-face emotional activation and cognitive restructuring in university students: A crossover experimental study using wearable monitoring

BACKGROUND

Arousal may be important for learning to restructure ones' negative cognitions, a core technique in depression treatment. In virtual reality (VR), situations may be experienced more vividly than, e.g., in an imaginative approach, potentially aiding the emotional activation of negative cognitions. However, it is unclear whether such activation and subsequent cognitive restructuring in VR elicits more physiological, e.g. changes in skin conductance (SC), heart rate (HR), and self-reported arousal.

METHOD

In a cross-over experiment, 41 healthy students experienced two sets, one in VR, one face-to-face (F2F), of three situations aimed at activating negative cognitions. Order of the sets and mode of delivery were randomised. A wristband wearable monitored SC and HR; self-reported arousal was registered verbally.

RESULTS

Repeated measures analyses of variance revealed significantly more SC peaks per minute, F (1, 40) = 13.89, p = .001, higher mean SC, F (1,40) = 7.47, p = .001, and higher mean HR, F (1, 40) = 75.84, p < .001 in VR compared to F2F. No differences emerged on the paired-samples t-test for self-reported arousal, t (40) = -1.35, p = .18.

DISCUSSION

To the best of our knowledge, this is the first study indicating that emotional activation and subsequent cognitive restructuring in VR can lead to significantly more physiological arousal compared to an imaginative approach. These findings need to be replicated before they can be extended to patient populations.

Exposure therapy in a virtual environment: Validation in obsessive compulsive disorder

Exposure and response prevention (ERP) is the current first-line psychological treatment for Obsessive-compulsive disorder (OCD). However, substantial inter-individual variability exists in treatment outcomes, including inadequate symptom improvements, and notable refusal and attrition rates. These are driven, in part, by impracticalities in simulating intrusive thoughts within clinical settings. Virtual reality (VR) offers the potential of overcoming these limitations in a manner that allows for finely controlled anxiety-provoking scenarios to be created within supportive clinical settings. To validate the potential of VR for treating contamination-based OCD, 22 patients undertook a VR ERP session and a matched session of the current gold-standard of in vivo ERP. In VR, patients were immersed within a contamination environment that permitted flexible delivery of customisable, graded exposure tasks. The VR environment utilised HTC Vive hardware, to allow for patients to both interact with, and physically move through the environment. Subjective and objective measures of distress were recorded, including heart and respiration rates. These measures indicate virtual and in vivo ERP sessions provoke consistent anxiety profiles across an exposure hierarchy. Virtual exposure was advantageous for engagement and adherence to tasks, and the therapeutic alliance was upheld. VR is a promising mechanism for ERP in contamination OCD.

Emotion Recognition in Immersive Virtual Reality: From Statistics to Affective Computing

Emotions play a critical role in our daily lives, so the understanding and recognition of emotional responses is crucial for human research. Affective computing research has mostly used non-immersive two-dimensional (2D) images or videos to elicit emotional states. However, immersive virtual reality, which allows researchers to simulate environments in controlled laboratory conditions with high levels of sense of presence and interactivity, is becoming more popular in emotion research. Moreover, its synergy with implicit measurements and machine-learning techniques has the potential to impact transversely in many research areas, opening new opportunities for the scientific community. This paper presents a systematic review of the emotion recognition research undertaken with physiological and behavioural measures using head-mounted displays as elicitation devices. The results highlight the evolution of the field, give a clear perspective using aggregated analysis, reveal the current open issues and provide guidelines for future research.

Psychedelics and virtual reality: parallels and applications

Psychedelic drugs and virtual reality (VR) each have the capacity to disrupt the rigidity and limitations of typical conscious experience. This article delineates the parallels among psychedelic and VR states as well as their potential synergistic applications in clinical and recreational settings. Findings indicate that, individually, psychedelics and VR are used in analogous ways to alter sensory experience and evoke awe. They are also both used in tandem with traditional therapies to treat a variety of mood disorders; their shared capacity to transiently alter perspective and disrupt rigid patterns of mental experience may underly their analogous and transdiagnostic therapeutic uses. In terms of their combined applications, a number of recreational users currently utilize psychedelics and VR together to enhance their experience. We propose that VR may be a useful tool for preparing hallucinogen-naïve participants in clinical trials for the sensory distortions experienced in psychedelic states. Given the critical role of "setting" in psychedelic treatment outcomes, we also detail how VR could be used to optimize the environment in psychedelic sessions. Finally, we provide considerations for future studies and detail how advancements in psychedelic and VR research can inform one another. Collectively, this article outlines a number of connections between psychedelics and VR, and, more broadly, is representative of growing scientific interest into the interactions among technology, psychopharmacology, and mental health.

Virtually Unexpected: No Role for Expectancy Violation in Virtual Reality Exposure for Public Speaking Anxiety

In the current study, we examined the role of expectancy violation and retrospective reasoning about the absence of feared outcomes in virtual reality exposure therapy (VRET). Participants fearful of public speaking were asked to give speeches in virtual reality. We asked each participant individually to report their expectancies about feared outcomes in public speaking situations and which of these could be tested in VRET. Each of the expectancies was categorized as being related to: (1) participants’ own reactions, (2) (overt) reactions of the audience, or (3) (covert) negative evaluation. We examined whether the proportion of testable expectancies could predict treatment outcome and which type of expectancies were evaluated as being more testable in VRET. Additionally, we experimentally manipulated retrospective reasoning about whether or not expectancies related to the overt reactions of the audience could be violated by providing verbal information after VRET about whether or not the virtual audience was interactive. A reduction in public speaking anxiety was observed from pre- to post-VRET. Treatment effects were, however, not predicted by the individually reported proportions of testable expectancies. Participants evaluated expectancies about their own reactions as being more testable in VRET compared to expectancies about reactions of the audience or about being negatively evaluated. In addition, we did not find evidence that the experimental manipulation regarding whether or not the audience was interactive influenced treatment effects. In conclusion, the results of the current study suggest that the effects of VRET are not univocally explained by the mechanism of expectancy violation.

It feels real: physiological responses to a stressful virtual reality environment and its impact on working memory

BACKGROUND

Virtual reality (VR) is increasingly used to study and treat psychiatric disorders. Its fidelity depends in part on the extent to which the VR environment provides a convincing simulation, for example whether a putatively stressful VR situation actually produces a stress response.

METHODS

We studied the stress response in 28 healthy men exposed either to a stressor VR elevator (which simulated travelling up the outside of a tall building and culminated in the participant being asked to step off the elevator platform), or to a control elevator. We measured psychological and physiological (salivary cortisol and alpha-amylase, blood pressure, pulse, skin conductance) stress indices. We also measured subsequent performance on the N-back task because acute stress has been reported to impact on working memory.

RESULTS

Compared to participants in the control elevator, those in the external elevator had increases in skin conductance, pulse and subjective stress and anxiety ratings, altered heart rate variability, and a delayed rise in cortisol. N-back performance was unaffected.

CONCLUSIONS

A putatively stressful VR elevator produces a physiological as well as a psychological stress response, supporting its use in the investigation and treatment of stress-related disorders, and its potential value as an experimental laboratory stressor.

Efficacy of virtual reality exposure therapy for the treatment of dental phobia in adults: A randomized controlled trial

BACKGROUND

Although Virtual Reality Exposure Therapy (VRET) has proven to be effective in the treatment of various subtypes of specific phobia, there is limited evidence of its role in the treatment of dental phobia.

METHOD

A single-blind RCT was conducted among 30 randomized patients with dental phobia to either VRET or informational pamphlet (IP) condition. Primary outcome anxiety measures (VAS-A, MDAS and DFS) were evaluated at baseline, pre- and post-intervention, 1-week, 3-months and 6-months follow-up. Secondary outcome measures assessed were pre-post behavioral avoidance, temporal variations of heart rate and VR-experience during and post-VRET, and dental treatment acceptance in both conditions at 6-month follow-up.

RESULTS

Intention to treat analysis, using a repeated measures MANOVA, revealed a multivariate interaction effect between time and condition (p = 0.015) for all primary outcome measures (all ps < 0.001). Only patients of the VRET condition showed a significant reduction in anxiety scores (mean reduction [s.d.]: VAS-A 44.4 [36.1]; MDAS 7.1 [5.4]; DFS 21.2 [13.1]) whereas the patients in the IP group did not (mean reduction [s.d.]: VAS-A -0.33 [7.7]; MDAS -0.33 [1.3]; DFS -1.9 [3.8]), F (15, 14) = 3.3, p = 0.015.

CONCLUSIONS

VRET was found to be efficacious in the treatment of dental phobia.

Physical Presence, Social Presence, and Anxiety in Participants with Social Anxiety Disorder During Virtual Cue Exposure

Although social anxiety disorders (SADs) are increasingly treated by means of virtual cue exposure, the mechanisms leading to sufficient anxiety levels and thus to a success of virtual reality exposure therapy are still poorly understood. Also, most studies with SAD participants fail to evaluate social presence, although it may be a more appropriate indicator for virtual social stress scenarios than physical presence. Hence, for the first time, this study sets out to examine the link between social presence, physical presence, and emotional responses to phobogenic virtual social stimuli. A group of n = 12 participants with SAD and n = 12 healthy controls were exposed to three social tasks in an interactive virtual environment (VE). Self-report measures of physical and social presence as well as state anxiety were used alongside heart rate measures to evaluate the virtual experience. Results show significantly higher anxiety levels-both self-report and physiological-in SAD participants than in controls. Also, socially anxious subjects reported to experience more copresence and mutual attention as well as a higher sense of being in the VE than their healthy peers. In sum, social presence experiences may be more predicative of the anxiety response in SAD individuals than physical presence. Especially attentional processes seem to crucially shape the interplay between presence and affective responses.

Within- and Between-Session Prefrontal Cortex Response to Virtual Reality Exposure Therapy for Acrophobia

Exposure Therapy (ET) has demonstrated its efficacy in the treatment of phobias, anxiety and Post-traumatic Stress Disorder (PTSD), however, it suffers a high drop-out rate because of too low or too high patient engagement in treatment. Virtual Reality Exposure Therapy (VRET) is comparably effective regarding symptom reduction and offers an alternative tool to facilitate engagement for avoidant participants. Neuroimaging studies have demonstrated that both ET and VRET normalize brain activity within a fear circuit. However, previous studies have employed brain imaging technology which restricts people's movement and hides their body, surroundings and therapist from view. This is at odds with the way engagement is typically controlled. We used a novel combination of neural imaging and VR technology-Functional Near-Infrared Spectroscopy (fNIRS) and Immersive Projection Technology (IPT), to avoid these limitations. Although there are a few studies that have investigated the effect of VRET on a brain function after the treatment, the present study utilized technologies which promote ecological validity to measure brain changes after VRET treatment. Furthermore, there are no studies that have measured brain activity within VRET session. In this study brain activity within the prefrontal cortex (PFC) was measured during three consecutive exposure sessions. N = 13 acrophobic volunteers were asked to walk on a virtual plank with a 6 m drop below. Changes in oxygenated (HbO) hemoglobin concentrations in the PFC were measured in three blocks using fNIRS. Consistent with previous functional magnetic resonance imaging (fMRI) studies, the analysis showed decreased activity in the DLPFC and MPFC during first exposure. The activity increased toward normal across three sessions. The study demonstrates potential efficacy of a method for measuring within-session neural response to virtual stimuli that could be replicated within clinics and research institutes, with equipment better suited to an ET session and at fraction of the cost, when compared to fMRI. This has application in widening access to, and increasing ecological validity of, immersive neuroimaging across understanding, diagnosis, assessment and treatment of, a range of mental disorders such as phobia, anxiety and PTSD or addictions.

Skin Conductance Reactivity to Standardized Virtual Reality Combat Scenes in Veterans with PTSD

Interest in virtual reality (VR) as a clinical tool to augment posttraumatic stress (PTSD) treatment has grown substantially in recent years due to advances in VR technology. Moreover, its potential assisted use in the PTSD diagnostic process has been recognized. In this study we examined physiological responding, skin conductance, to a standardized presentation of non-personalized combat-related VR events (e.g. encountering enemy fire; explosions) as compared to non-combat classroom VR events in 19 Veterans with and 24 Veterans without combat-related PTSD who had been deployed to Iraq and Afghanistan. Veterans watched a total of 12 VR scenarios-six combat-related and six non-combat-related-with each scenario gradually increasing in emotional intensity by adding more VR events in addition to repeating prior VR events. Results show that Veterans with PTSD displayed larger skin conductance reactivity across VR combat events, but not for non-combat VR events, as compared to combat Veterans without PTSD. Nevertheless, Veterans with and without PTSD showed a similar reduction of emotional arousal to repeated presentation of the same VR combat events. Within the PTSD sample, the elevated level of VR combat-related arousal correlated marginally with severity of hyperarousal symptoms. This study confirms that the use of a non-personalized and standardized VR presentation successfully distinguishes Veterans with PTSD from those without on a measure of psychophysiological arousal to combat-related VR stimuli. The assessment of physiological reactivity during the repeated presentation of standardized, trauma-related VR events highlights its use for PTSD assessment as well as treatment.

Virtual reality exposure therapy for fear of driving: analysis of clinical characteristics, physiological response, and sense of presence

OBJECTIVE

To investigate the reactions of women with driving phobia to a therapeutic program of scheduled virtual reality exposure treatment (VRET) sessions.

METHODS

The study intervention consisted of a computer game with car-driving scenarios that included several traffic situations. We investigated the participants' sense of presence, subjective distress, and physiological responses during eight virtual-reality exposures. We also evaluated clinical characteristics, driving cognitions, and quality of life in the participants.

RESULTS

Thirteen women were selected. Eight were able to complete the protocol. After VRET, there was a decrease in the frequency of distorted thoughts and state anxiety scores, as well as a slight improvement in quality of life. Subjective discomfort scores, heart rate variation, and sense of presence scores confirmed that there was sense of presence in the virtual reality environment.

CONCLUSION

All patients showed some degree of improvement and demonstrated different levels of anxiety in subsequent in vivo driving experiences. Our findings suggest that VRET could be used to facilitate in vivo exposure, because it can induce presence/immersion and reduce anxiety in patients with specific phobia. Furthermore, VRET is not associated with any type of risk.

Computational Psychometrics for Modeling System Dynamics during Stressful Disasters

Disasters can be very stressful events. However, computational models of stress require data that might be very difficult to collect during disasters. Moreover, personal experiences are not repeatable, so it is not possible to collect bottom-up information when building a coherent model. To overcome these problems, we propose the use of computational models and virtual reality integration to recreate disaster situations, while examining possible dynamics in order to understand human behavior and relative consequences. By providing realistic parameters associated with disaster situations, computational scientists can work more closely with emergency responders to improve the quality of interventions in the future.

Targeting memory reconsolidation to prevent the return of fear in patients with fear of flying

BACKGROUND

When a memory is recalled, it may again exist in a labile state and stored information becomes amenable to change, a psychobiological process known as reconsolidation. Exposure therapy for anxiety disorders involves accessing a fear memory and modifying it with less fearful information. A preclinical study reported that providing a reminder of a fear memory 10 min prior to extinction training in humans decreased fear up to 1 year later (Schiller et al., 2010).

METHODS

For this pilot clinical study, we used virtual reality exposure therapy (VRE) for fear of flying (FoF) to determine if using a cue to reactivate the memory of the feared stimulus 10 min prior to exposure sessions leads to fewer anxiety-related behaviors and a more durable response compared to a neutral cue. FoF participants (N = 89) received four sessions of anxiety management training followed by four sessions of VRE. Participants were randomly assigned to receive an FoF cue (reactivation group) or a neutral cue (control group) prior to the VRE sessions. Heart rate (HR) and skin conductance levels (SCLs) were collected during posttreatment and 3-month follow-up assessments as objective markers of fear responding.

RESULTS

Treatment was effective and all clinical measures improved equally between groups at posttreatment with maintained gains through follow-ups. Significant differences were identified with regard to HR and SCL indices.

CONCLUSIONS

These results suggest that memory reactivation prior to exposure therapy did not have an impact on clinical measures but may enhance the effect of exposure therapy at the physiological level.

Creating virtual environments for phobia treatment

In this paper, we try to present the problems of the modern approach to treating various phobias. Virtual environments created by virtual reality (VR) tools can help to make the treatment of certain types of phobias more efficient. Attention to this form of phobia treatment with the help of VR is on the rise in the world, so we are also monitoring its development, as well. Our paper introduces the necessary hardware and software that has been piloted in our department, but also methods of creating virtual environments, models and application designed for medical therapies of patients. In ourworkwe have searched for and tested the following methods for creating virtual environments: A) modelling using computer graphics, B) modelling animation using animation programs, C) taking pictures of static objects and scenes, D) filming moving objects and scenes using classic video or special scanning techniques to create 360∘ panoramas or E) any combination of these methods.

Influence of Music on Anxiety Induced by Fear of Heights in Virtual Reality

Music is a potent mood regulator that can induce relaxation and reduce anxiety in different situations. While several studies demonstrate that certain types of music have a subjective anxiolytic effect, the reported results from physiological responses are less conclusive. Virtual reality allows us to study diverse scenarios of real life under strict experimental control while preserving high ecological validity. We aimed to study the modulating effect of music on the anxiety responses triggered by an immersive virtual reality scenario designed to induce fear of heights. Subjects experienced a virtual scenario depicting an exterior elevator platform ascending and descending the total height of its 350 meters tall supporting structure. Participants were allocated to either a group that experienced the elevator ride with background music or without, in a between-groups design. Furthermore, each group included participants with different degrees of fear of heights, ranging from low to high fear. Recordings of heart rate, galvanic skin response, body balance, and head movements were obtained during the experiments. Subjective anxiety was measured by means of three questionnaires. The scenario produced significant changes in subjective and physiological measures, confirming its efficacy as a stressor. A significant increase in state anxiety was found between pre and post-assessment in the silence group, but not in the music group, indicating that post-stress recovery was faster in the musical group. Results suggest that music can ameliorate the subjective anxiety produced by fear of heights.

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.

Virtual reality exposure in anxiety disorders: impact on psychophysiological reactivity

OBJECTIVES

Anxiety disorders are among the most frequently encountered psychiatric disorders. Recommended treatments include cognitive behavioural therapy (CBT) and/or medication. In recent years, beneficial effects of virtual reality (VR) exposure therapy have been shown, making this technique a promising addition to CBT. However, the ability of VR to mimic threatening stimuli in a way comparable to in vivo cues has been discussed. In particular, it has been questioned whether VR is capable of provoking psychophysiological symptoms of anxiety. Since psychophysiological arousal is considered a prerequisite for effective exposure treatment, this systematic review aims to evaluate the evidence for the potential of VR exposure to evoke and modulate psychophysiological fear reactions.

METHODS

PubMed and PsycINFO/Academic Search Premier databases were searched. Thirty-eight studies investigating challenge or habituation effects were included.

RESULTS

VR exposure does provoke psychophysiological arousal, especially in terms of electrodermal activity. Results on psychophysiological habituation in VR are inconclusive. Study design and methodological rigour vary widely.

CONCLUSIONS

Despite several limitations, this review provides evidence that VR exposure elicits psychophysiological fear reactions in patients and healthy subjects, rendering VR a promising treatment for anxiety disorders, and a potent research tool for future investigations of psychophysiological processes and their significance during exposure treatment.

Afraid to be there? Evaluating the relation between presence, self-reported anxiety, and heart rate in a virtual public speaking task

The link between anxiety and presence in a virtual environment (VE) is still a subject of an unresolved debate, with little empirical research to support theoretical claims. Thus, the current study analyzed presence, self-reported anxiety, and a physiological parameter (heart rate [HR]) in a sample of 30 high anxious and 35 low anxious participants. Both groups delivered a 5 minute speech in a virtual lecture hall. Results indicate no mediating influences of presence on group differences in self-reported state anxiety during the speech, but point toward negative correlations between state anxiety and the iGroup Presence Questionnaire (IPQ) scales "sense of being there" and "realism." Furthermore, HR was found to be unrelated to self-reported presence. Only the IPQ scale "spatial presence" showed a marginally significant influence on group differences in state anxiety. The present results support the assumption that presence and anxiety are logically distinct, meaning that presence does not directly influence the intensity of an emotion felt in a VE. Rather, it constitutes a precondition for an emotion to be at all elicited by a VE. Also, HR has proven to be no adequate substitute measure for presence, since it only assesses anxiety not presence. It may, however, mediate the interplay between trait anxiety and state anxiety. Possible implications of the current findings are discussed alongside the problem of using presence questionnaires that seem to be prone to subjective bias (i.e., participants confusing presence and emotion).

Eliciting affect via immersive virtual reality: a tool for adolescent risk reduction

OBJECTIVE

A virtual reality environment (VRE) was designed to expose participants to substance use and sexual risk-taking cues to examine the utility of VR in eliciting adolescent physiological arousal.

METHODS

42 adolescents (55% male) with a mean age of 14.54 years (SD = 1.13) participated. Physiological arousal was examined through heart rate (HR), respiratory sinus arrhythmia (RSA), and self-reported somatic arousal. A within-subject design (neutral VRE, VR party, and neutral VRE) was utilized to examine changes in arousal.

RESULTS

The VR party demonstrated an increase in physiological arousal relative to a neutral VRE. Examination of individual segments of the party (e.g., orientation, substance use, and sexual risk) demonstrated that HR was significantly elevated across all segments, whereas only the orientation and sexual risk segments demonstrated significant impact on RSA.

CONCLUSIONS

This study provides preliminary evidence that VREs can be used to generate physiological arousal in response to substance use and sexual risk cues.

The effect of perspective on presence and space perception

In this paper we report two experiments in which the effect of perspective projection on presence and space perception was investigated. In Experiment 1, participants were asked to score a presence questionnaire when looking at a virtual classroom. We manipulated the vantage point, the viewing mode (binocular versus monocular viewing), the display device/screen size (projector versus TV) and the center of projection. At the end of each session of Experiment 1, participants were asked to set their preferred center of projection such that the image seemed most natural to them. In Experiment 2, participants were asked to draw a floor plan of the virtual classroom. The results show that field of view, viewing mode, the center of projection and display all significantly affect presence and the perceived layout of the virtual environment. We found a significant linear relationship between presence and perceived layout of the virtual classroom, and between the preferred center of projection and perceived layout. The results indicate that the way in which virtual worlds are presented is critical for the level of experienced presence. The results also suggest that people ignore veridicality and they experience a higher level of presence while viewing elongated virtual environments compared to viewing the original intended shape.

Influence of real and virtual heights on standing balance

Fear and anxiety induced by threatening scenarios, such as standing on elevated surfaces, have been shown to influence postural control in young adults. There is also a need to understand how postural threat influences postural control in populations with balance deficits and risk of falls. However, safety and feasibility issues limit opportunities to place such populations in physically threatening scenarios. Virtual reality (VR) has successfully been used to simulate threatening environments, although it is unclear whether the same postural changes can be elicited by changes in virtual and real threat conditions. Therefore, the purpose of this study was to compare the effects of real and virtual heights on changes to standing postural control, electrodermal activity (EDA) and psycho-social state. Seventeen subjects stood at low and high heights in both real and virtual environments matched in scale and visual detail. A repeated measures ANOVA revealed increases with height, independent of visual environment, in EDA, anxiety, fear, and center of pressure (COP) frequency, and decreases with height in perceived stability, balance confidence and COP amplitude. Interaction effects were seen for fear and COP mean position; where real elicited larger changes with height than VR. This study demonstrates the utility of VR, as simulated heights resulted in changes to postural, autonomic and psycho-social measures similar to those seen at real heights. As a result, VR may be a useful tool for studying threat related changes in postural control in populations at risk of falls, and to screen and rehabilitate balance deficits associated with fear and anxiety.

Development and Validation of a Virtual Environment to Evaluate the Capacity in Executing the Safety Procedures in Recreational Scuba Diving

BACKGROUND

Recreational scuba diving courses have safety procedures in their curriculum to be followed in case of emergencies. However, the actual diving is often performed months after the training. Because these procedures are counterinstinctive, when emergencies occur the divers in panic cannot follow them.

MATERIALS AND METHODS

Thus a virtual environment was developed, presenting several emergency situations that may occur during a recreational dive. It used an Intel(®) (Santa Clara, CA) Core™2 Duo (1.66 GHz, 1 GB RAM) PC and Adobe (San Jose, CA) Fireworks and Adobe Flash 8 for animation and programming. The procedures to be followed were the standards of the Association of Dive Schools.

RESULTS AND CONCLUSION

This research found that the performance of divers on a questionnaire on diving safety procedures is very different than in the virtual environment.

The effect of repeated virtual nicotine cue exposure therapy on the psychophysiological responses: a preliminary study

OBJECTIVE

Smoking related cues may elicit smoking urges and psychophysiological responses in subjects with nicotine dependence. This study aimed to investigate the effect of repeated virtual cue exposure therapy using the surround-screen based projection wall system on the psychophysiological responses in nicotine dependence.

METHODS

The authors developed 3-dimensional neutral and smoking-related environments using virtual reality (VR) technology. Smoking-related environment was a virtual bar, which comprised both object-related and social situation cues. Ten subjects with nicotine dependence participated in 4-week (one session per week) virtual cue exposure therapy. Psychophysiological responses [electromyography (EMG), skin conductance (SC), and heart rate] and subjective nicotine craving were acquired during each session.

RESULTS

VR nicotine cue elicited greater psychophysiological responses and subjective craving for smoking than did neutral cue, and exposure to social situation cues showed greater psychophysiological responses in SC and EMG than did object-related cues. This responsiveness decreased during the course of repeated therapy.

CONCLUSION

The present study found that both psychophysiological responses and subjective nicotine craving were greater to nicotine cue exposure via projection wall VR system than to neutral cues and that enhanced cue reactivity decreased gradually over the course of repeated exposure therapy. These results suggest that VR cue exposure therapy combined with psychophysiological response monitoring may be an alternative treatment modality for smoking cessation, although the current findings are preliminary.

Fixing our focus: training attention to regulate emotion

Empirical studies have frequently linked negative attentional biases with attentional dysfunction and negative moods; however, far less research has focused on how attentional deployment can be an adaptive strategy that regulates emotional experience. The authors argue that attention may be an invaluable tool for promoting emotion regulation. Accordingly, they present evidence that selective attention to positive information reflects emotion regulation and that regulating attention is a critical component of the emotion regulatory process. Furthermore, attentional regulation can be successfully trained through repeated practice. The authors ultimately propose a model of attention training methodologies integrating attention-dependent emotion regulation strategies with attention networks. Although additional interdisciplinary research is needed to bolster these nascent findings, meditative practices appear to be among the most effective training methodologies in enhancing emotional well-being. Further exploration of the positive and therapeutic qualities of attention warrants the empirical attention of social and personality psychologists.

Virtual reality exposure therapy in anxiety disorders: a systematic review of process-and-outcome studies

In recent years, virtual reality exposure therapy (VRET) has become an interesting alternative for the treatment of anxiety disorders. Research has focused on the efficacy of VRET in treating anxiety disorders: phobias, panic disorder, and posttraumatic stress disorder. In this systematic review, strict methodological criteria are used to give an overview of the controlled trials regarding the efficacy of VRET in patients with anxiety disorders. Furthermore, research into process variables such as the therapeutic alliance and cognitions and enhancement of therapy effects through cognitive enhancers is discussed. The implications for implementation into clinical practice are considered.

Psychophysiological responses to robotic rehabilitation tasks in stroke

This paper presents the analysis of four psychophysiological responses in post-stroke upper extremity rehabilitation. The goal was to determine which psychophysiological responses would provide the most reliable information about subjects' psychological states during rehabilitation. Heart rate, skin conductance, respiration, and skin temperature were recorded in a stroke group and a control group during two difficulty levels of a pick-and-place task performed in a virtual environment using a haptic robot and during a cognitive task. Psychophysiological measurements were correlated with results of a self-report questionnaire. All four responses showed significant changes in response to the different tasks. Skin conductance differentiated between the two difficulty levels and was correlated with self-reported arousal in both stroke and control groups. Skin temperature differentiated between the two difficulty levels for the control group, but provided poor results for the stroke group. Heart rate and respiration increased during tasks, but their connection to psychological state was unclear. Results suggest that, of the four measured responses, skin conductance offers the most potential as a psychological state indicator, with other measures providing supplementary information. Psychophysiological measurements could thus be used in closed-loop biocooperative systems that would detect the user's psychological state and change the course of therapy accordingly.

Virtual reality exposure therapy in the treatment of driving phobia

A growing number of researches has appeared on virtual reality exposure therapy (VRET) to treat anxiety disorders. The purpose of this article was to review some evidences that support the VRET efficacy to treat driving phobia. The studies were identified through computerized search (PubMed/Medline, Web of Science, and Scielo databases) from 1984 to 2007. Some findings are promising. Anxiety/avoidance ratings declined from pre to post-treatment. VRET may be used as a first step in the treatment of driving phobia, as long as it may facilitate the in vivo exposure, thus reducing risks and high costs of such exposure. Notwithstanding, more randomized/controlled clinical trials are required to prove its efficacy.

Virtual reality as a mechanism for exposure therapy

Virtual reality (VR) is as effective in inducing emotional responses as reality and its application is extremely valuable in exposure treatment. In virtual environments, the patients experience similar physiological symptoms and fear as they do in real life situations, thereby facilitating the habituation process. Our goal is to offer an overview of the current panorama of VR and psychotherapy, underlining the (virtual) exposure technique and the studies that focus on panic disorder treatment through the use of VR. The literature was revised through consultation to the ISI and PubMed databases. Virtual exposure treatment offers good results and great patient acceptability. However, despite the importance of this data for the evaluation of treatment efficacy, only a few studies measure physiological responses during exposure. Lack of controlled studies and standardized treatment protocols were observed. Despite the great advance of VR use in psychotherapy, a great deal of its potential is still unknown, therefore requiring the creation of new virtual environments so that controlled studies regarding its clinical application can be conducted. Throughout the process of elaboration and investigation, clinical experiences in virtual environments must be related to real experiences in a flexible context that combines relevant cultural, physical and cognitive aspects.

Affective outcomes of virtual reality exposure therapy for anxiety and specific phobias: a meta-analysis

Virtual reality exposure therapy (VRET) is an increasingly common treatment for anxiety and specific phobias. Lacking is a quantitative meta-analysis that enhances understanding of the variability and clinical significance of anxiety reduction outcomes after VRET. Searches of electronic databases yielded 52 studies, and of these, 21 studies (300 subjects) met inclusion criteria. Although meta-analysis revealed large declines in anxiety symptoms following VRET, moderator analyses were limited due to inconsistent reporting in the VRET literature. This highlights the need for future research studies that report uniform and detailed information regarding presence, immersion, anxiety and/or phobia duration, and demographics.

Cardiovascular, electrodermal, and respiratory response patterns to fear- and sadness-inducing films

Responses to fear- and sadness-inducing films were assessed using a broad range of cardiovascular (heart rate, T-wave amplitude, low- and high-frequency heart rate variability, stroke volume, preejection period, left-ventricular ejection time, Heather index, blood pressure, pulse amplitude and transit time, and finger temperature), electrodermal (level, response rate, and response amplitude), and respiratory (rate, tidal volume and its variability, inspiratory flow rate, duty cycle, and end-tidal pCO(2)) measures. Subjective emotional experience and facial behavior (Corrugator Supercilii and Zygomaticus Major EMG) served as control measures. Results indicated robust differential physiological response patterns for fear, sadness, and neutral (mean classification accuracy 85%). Findings are discussed in terms of the fight-flight and conservation-withdrawal responses and possible limitations of a valence-arousal categorization of emotion in affective space.