虚拟现实暴露疗法在社交焦虑中的应用:效果、机制及展望

由于传统干预方法的诸多局限,虚拟现实暴露疗法(virtual reality exposure therapy,VRET)逐渐应用于对社交焦虑的干预,VRET是将虚拟现实技术与传统行为暴露治疗相结合而形成的一种新的干预方法。文章总结了VRET的三个发展阶段及其研究范式,述评了在VRET过程中的作用机制。未来研究可致力于设计更加自然的人机交互技术,实现技术与社交焦虑治疗的深度融合以及关注第三人称视角应用的作用及机制。     

焦虑障碍的虚拟现实暴露疗法研究述评

虚拟现实暴露疗法(VRET)是传统的行为疗法的一种转换形式, 也是经典的现实情境暴露疗法的替代性治疗形式。虚拟现实整合了即时计算机图形学、身体感觉传感、视觉成像技术, 给来访者提供近似真实的、可以沉浸(immersion)和交互作用的虚拟环境。研究者采用虚拟现实暴露疗法治疗幽闭恐怖症、恐高症、飞行恐怖症、创伤后应激障碍、惊恐障碍等焦虑障碍, 并且关注虚拟现实暴露疗法的认知机制以及心理生理机制。实验研究表明, 虚拟现实暴露疗法在治疗焦虑障碍时是有效的。被试经过治疗之后, 对情境的控制感和自我效能感提升, 消极自我评价降低, 对创伤事件的容忍力提高, 重新获得对情境的控制感。与心率指标相比, 皮肤电是预测虚拟现实暴露疗法治疗效果更好的指标。虚拟现实暴露疗法还处于实验验证阶段, 并没有应用到实际临床中, 需要更加规范的实验设计验证该疗法的认知机制以及心理生理机制。虚拟现实暴露疗法结合功能磁共振成像(FMRI)用于心理治疗, 会是未来发展的新方向。     

Is the street-crossing behavior with a head-mounted display different from that behavior in a CAVE? A study among young adults and children

The use of virtual reality (VR) has become increasingly popular in the field of traffic psychology, where realistic traffic situations can be simulated and pedestrians‘ actual crossing behavior can be studied. There are two main kinds of pedestrian simulators: one uses a technology based on rear-projection screens (Cave Automatic Virtual Environment, or CAVE); the other uses a head-mounted display (HMD). Despite their extensive use, it is yet to determine whether they are equally suitable for studying street crossing. The present study was aimed at comparing street-crossing behavior and subjective evaluations in an HMD-based (HTC vive pro) pedestrian simulator and a CAVE-like pedestrian simulator, among young adults and 12-year-old children. Thirty young adults and twenty-six children performed 36 street-crossing trials (combining different speeds, traffic conditions, and gap sizes) on each of the two simulators. The results indicated that, compared to the CAVE-condition participants, HMD-condition participants accepted more crossing trials (hence, shorter gaps), initiated their crossings sooner, crossed at a slower speed, had shorter safety margins, and caused more collisions. The main difference between the two devices was in crossing initiation, which occurred markedly earlier (1.72 s) with the HMD than in the CAVE: the perception–action coupling was less finely tuned in the CAVE, probably because visual information in front of the pedestrian was missing due the absence of ground projection and 3D rendering. A significant effect of vehicle-approach speed was observed for both devices, with more unsafe behaviors at 60 km/h than at 40 km/h. Children displayed riskier crossing behavior than young adults did, with more accepted crossings, slower crossing speeds, shorter safety margins, and higher collision rates, especially in the HMD. Compared to the CAVE, the HMD received higher ratings for level of presence and a preference for VR, but also higher simulator-sickness scores. No adverse effects of exposure to virtual reality was found on stereoacuity or postural balance. The suitability of using CAVE and HMD simulators is discussed, especially for studying child pedestrians.     

Do self-statements enhance the effectiveness of virtual reality exposure therapy? A comparative evaluation in acrophobia.

There is a clear need for more detailed analysis of the role of cognitive self-statements in virtual reality exposure therapy (VRET). To date, no research on this topic has been done. The primary aim of this study was to investigate whether coping self-statements would enhance the effectiveness of VRET. In a randomized crossover design, 26 patients with acrophobia (DSM-IV diagnosis of specific phobia) were randomly assigned to two sessions of VRET followed by two sessions of VRET plus coping self-statements, or the other way around: first two sessions of VRET plus coping self-statements followed by two sessions of VRET. Results showed that VRET, regardless of addition of coping self-statements, decreased anxiety of heights, decreased avoidance of height situations, and improved attitudes towards heights. However, at 6-month follow-up, most gains during treatment were not fully retained.     

Creating state of the art,next-generation Virtual Reality exposure therapies for anxiety disorders using consumer hardware platforms: design considerations and future directions

Decades of research and more than 20 randomized controlled trials show that Virtual Reality exposure therapy (VRET) is effective in reducing fear and anxiety. Unfortunately, few providers or patients have had access to the costly and technical equipment previously required. Recent technological advances in the form of consumer Virtual Reality (VR) systems (e.g. Oculus Rift and Samsung Gear), however, now make widespread use of VRET in clinical settings and as self-help applications possible. In this literature review, we detail the current state of VR technology and discuss important therapeutic considerations in designing self-help and clinician-led VRETs, such as platform choice, exposure progression design, inhibitory learning strategies, stimuli tailoring, gamification, virtual social learning and more. We illustrate how these therapeutic components can be incorporated and utilized in VRET applications, taking full advantage of the unique capabilities of virtual environments, and showcase some of these features by describing the development of a consumer-ready, gamified self-help VRET application for low-cost commercially available VR hardware. We also raise and discuss challenges in the planning, development, evaluation, and dissemination of VRET applications, including the need for more high-quality research. We conclude by discussing how new technology (e.g. eye-tracking) can be incorporated into future VRETs and how widespread use of VRET self-help applications will enable collection of naturalistic “Big Data” that promises to inform learning theory and behavioral therapy in general.     

Virtual reality exposure therapy: 150-degree screen to desktop PC.

Virtual reality exposure therapy (VRET) developed using immersive or semi-immersive virtual environments present a usability problem for practitioners. To meet practitioner requirements for lower cost and portability VRET programs must often be ported onto desktop environments such as the personal computer (PC). However, success of VRET has been shown to be linked to presence, and the environment's ability to evoke the same reactions and emotions as a real experience. It is generally accepted that high-end virtual environments (VEs) are more immersive than desktop PCs, but level of immersion does not always predict level of presence. This paper reports on the impact on presence of porting a therapeutic VR application for schizophrenia from the initial research environment of a semi-immersive curved screen to PC. Presence in these two environments is measured both introspectively and across a number of causal factors thought to underlie the experience of presence. Results show that the VR exposure program successfully made users feel they were "present" in both platforms. While the desktop PC achieved higher scores on presence across causal factors participants reported they felt more present in the curved screen environment. While comparison of the two groups was statistically significant for the PQ but not for the IPQ, subjective reports of experiences in the environments should be considered in future research as the success of VRET relies heavily on the emotional response of patients to the therapeutic program.     

Exposure Therapy for Posttraumatic Stress Disorder: A Meta-Analysis

This meta-analysis compares the findings of empirical studies that employ either a traditional form of cognitive–behavioral-based exposure therapy or virtual reality exposure therapy (VRET) for the treatment of posttraumatic stress disorder (PTSD) to determine which is more viable and effective. Statistical analyses were performed on 26 studies to determine pre- to posttreatment effect sizes and interactions. Results demonstrated a trend toward significance in favor of traditional exposure therapy showing lower posttreatment PTSD. Limitations included a restricted number of relevant studies; future research on VRET for PTSD should orient more to experimental designs, larger samples, and increased use of control groups.     

Virtual Reality Exposure Therapy for PTSD symptoms after a road accident: an uncontrolled case series

This report examined whether Virtual Reality Exposure Therapy (VRET) could be used in the treatment of posttraumatic stress disorder (PTSD) symptoms in the aftermath of a serious motor vehicle accident. Six individuals reporting either full or severe subsyndromal PTSD completed 10 sessions of VRET, which was conducted using software designed to create real-time driving scenarios. Results indicated significant reductions in posttrauma symptoms involving reexperiencing, avoidance, and emotional numbing, with effect sizes ranging from d=.79 to d=1.49. Indices of clinically significant and reliable change suggested that the magnitude of these changes was meaningful. Additionally, high levels of perceived reality ("presence") within the virtual driving situation were reported, and patients reported satisfaction with treatment. Results are discussed in light of the possibility for VRET to be useful in guiding exposure in the treatment of PTSD following road accidents.     

Cognitive-behavioral treatment and antidepressants combined with virtual reality exposure for patients with chronic agoraphobia

In this study we compared the efficacy of virtual reality exposure combined with cognitive-behavioral therapy (VRET) to that of traditional cognitive-behavioral therapy (CBT) alone in reducing phobic symptoms in a sample of patients with long-term agoraphobia. The study was a between-subject design with three experimental conditions (VRET group, N = 30; CBT group, N = 30; and medication only group, N = 20) and repeated measures (pre-treatment, post-treatment, and six-month follow-up). All patients were receiving antidepressant medication. Results showed that all therapies were statistically effective both at post-treatment and six-month follow-up. The VRET group showed clinical improvement in most variables measured at follow-up. The CBT group showed the highest dropout rates. These results are discussed pointing out that VRET probably serves as an intermediate procedure for an efficient exposure to phobic stimuli. Besides describing the advantages of VRET for the treatment of agoraphobia symptoms in cost-benefit terms, the study also considered issues related to higher treatment adherence and motivation.     

Virtual reality treatment versus exposure in vivo: a comparative evaluation in acrophobia

The aim of the present study was to evaluate the effectiveness of low-budget virtual reality (VR) exposure versus exposure in vivo in a between-group design in 33 patients suffering from acrophobia. The virtual environments used in treatment were exactly copied from the real environments used in the exposure in vivo program. VR exposure was found to be as effective as exposure in vivo on anxiety and avoidance as measured with the Acrophobia Questionnaire (AQ), the Attitude Towards Heights Questionnaire (ATHQ) and the Behavioral Avoidance Test (BAT). Results were maintained up to six months follow-up. The present study shows that VR exposure can be effective with relatively cheap hardware and software on stand-alone computers currently on the market. Further studies into the effectiveness of VR exposure are recommended in other clinical groups as agoraphobics and social phobics and studies in which VR exposure is compared with more emerging virtual worlds as presented in CAVE-type systems.     

Virtual Reality and Cognitive-Behavioral Therapy for Driving Anxiety and Aggression in Veterans: A Pilot Study

Within the U.S. military, motor vehicle accidents (MVAs) are the leading cause of preventable morbidity and mortality. Prior combat exposure and anxiety symptoms are associated with risky and aggressive driving, which is responsible for over half of MVA fatalities. Therefore, interventions are needed to reduce driving anxiety and aggression in veterans in order to mitigate the public health impact of MVAs. Virtual reality exposure therapy (VRET) offers safe, controlled exposure to distressing stimuli. The current study piloted a novel virtual reality and cognitive behavioral intervention (VRET + CBT) for veterans that integrated both anxiety and anger management components. Virtual reality driving scenarios were delivered in a driving simulator and tailored for the military population. Six previously deployed veterans completed eight intervention sessions, as well as pre/post, one month follow-up and six to nine month follow-up assessments. Repeated measures ANOVAs demonstrated significant decline and large effect sizes for PTSD symptoms, driving phobia, hyperarousal in driving situations, anxiety/anger-related thoughts and behaviors, and risky driving. Hyperarousal in driving situations declined by 69%, aggressive driving declined by 29%, and risky driving declined by 21%. Treatment gains were maintained at follow-up. Recruitment, retention, immersion, simulator sickness scores, and qualitative feedback demonstrated feasibility of the intervention. Implications for future research and adaptation are discussed.     

Use of Virtual Environments for the Acquisition of Spatial Knowledge: Comparison Among Different Visual Displays

This experiment investigated the effects of three visual display systems differing in immersiveness: A wide field of view (FOV) 3-D helmet-mounted display (HMD); a 3-D HMD with a narrow FOV; and a stationary, rear-projection, wide screen display (WSD). Soldiers explored a virtual environment (VE) representing an actual, unfamiliar heliport. Measures of spatial knowledge of the heliport and presence were recorded. Pretest-posttest differences showed that exploration of the VE transferred to the actual heliport. Visual display had no effect on spatial knowledge of the heliport or on presence. Measures of susceptibility to presence correlated with reported presence only in the WSD condition. Results question popular notions about VEs, which assume that visual-spatial learning is more effective the more immersive the visual display.     

Belief disconfirmation versus habituation approaches to situational exposure in panic disorder with agoraphobia: a pilot study

Exposure therapy and cognitive behaviour therapy (CBT) are both effective in the treatment of panic disorder with agoraphobia. Cognitive theories suggest that the way in which exposure to avoided situations is implemented in either treatment may be crucial. In particular, it is suggested that clinical improvement will be greatest if opportunities for disconfirmation of feared catastrophes are maximized. In a small pilot study, 16 patients with panic disorder and (moderate or severe) agoraphobia were randomly allocated to either habituation based exposure therapy (HBET) or exposure planned as a belief disconfirmation strategy and accompanied by dropping of safety-seeking behaviours. Both treatments were brief (total of 3.25 h of exposure) and were similar in terms of expectancy of change. Patients in the CBT condition showed significantly greater improvements in self-report measures of anxiety, panic and situational avoidance. They also completed significantly more steps in a standardized behavioural walk, during which they experienced significantly less anxiety. The controlled effect sizes for CBT were substantial (range 1.7-2.7), which suggests it may be a particularly efficient way of managing therapeutic exposure to feared situations in panic disorder with agoraphobia. Further research is needed to clarify the mechanism of change involved.     

Posttraumatic Stress Disorder and Chronic Pain Arising from Motor Vehicle Accidents: Efficacy of Interoceptive Exposure Plus Trauma-Related Exposure Therapy

Preliminary data are presented on the pattern of treatment response of combining interoceptive exposure (IE) with trauma-related exposure therapy (TRE) in five female patients with posttraumatic stress disorder (PTSD) and comorbid chronic musculoskeletal pain originating from motor vehicle accidents. Treatment consisted of four sessions of IE followed by eight sessions of TRE. Four participants reported a reduction in PTSD symptoms after completing treatment, and three no longer met diagnostic criteria for PTSD. Although both interventions were associated with reductions in PTSD symptoms, TRE was associated with greater reductions in PTSD symptoms than IE and was particularly effective at reducing avoidance. IE was associated with larger reductions in anxiety sensitivity than TRE. Pain symptoms lessened slightly during IE and then worsened following TRE. Anxiety decreased after completing treatment, whereas panic and depressive symptoms responded less so. Three individuals completed a 3-month follow-up assessment. There was no change in their PTSD diagnostic status, and all experienced a slight loss of pre–post gains, particularly involving the return of pain. Clinical and research implications are discussed.     

Head-mounted displays for clinical virtual reality applications: pitfalls in understanding user behavior while using technology.

The use of virtual environments with head-mounted displays (HMDs) offers unique assets to the evaluation and therapy of clinical populations. However, research examining the effects of this technology on clinical populations is sparse. Understanding how wearers interact with the HMD is vital. Discomfort leads to altered use of the HMD that could confound performance measures; the very measures which might be used as tools for clinical decision making. The current study is a post-hoc analysis of the relationship between HMD use and HMD comfort. The analysis was conducted to examine contributing factors for a high incidence of simulator sickness observed in an HMD-based driving simulator. Pearson correlation analysis was used to evaluate objective and subjective measures of HMD performance and self-reported user comfort ratings. The results indicated weak correlations between these variables, indicating the complexity of quantifying user discomfort and HMD performance. Comparison of two case studies detailing user behavior in the virtual environment demonstrates that selected variables may not capture how individuals use the HMD. The validity and usefulness of the HMD-based virtual environments must be understood to fully reap the benefits of virtual reality (VR) in rehabilitation medicine.     

Target detection performance in helmet-mounted and conventional dome displays

An experiment was conducted to assess visual target detection performance using a helmet-mounted display (HMD) and a conventional flight simulation dome display. Measures of workload and mood were also obtained. Participants in both viewing conditions scanned an area 120 degrees vertical by 240 degrees horizontal while attempting to locate targets that appeared to be approaching them from one of a possible 18 locations. Results indicated significantly superior performance in the conventional dome display. Workload and mood measures also showed a significant advantage for the dome display. Results are discussed in terms of their implications for the design and use of HMD systems as components of airborne virtual environment interfaces.     

The impact of cognitive behavioral therapy on post event processing among those with social anxiety disorder

Individuals with social anxiety are prone to engage in post event processing (PEP), a post mortem review of a social interaction that focuses on negative elements. The extent that PEP is impacted by cognitive behavioral therapy (CBT) and the relation between PEP and change during treatment has yet to be evaluated in a controlled study. The current study used multilevel modeling to determine if PEP decreased as a result of treatment and if PEP limits treatment response for two types of cognitive behavioral treatments, a group-based cognitive behavioral intervention and individually based virtual reality exposure. These hypotheses were evaluated using 91 participants diagnosed with social anxiety disorder. The findings suggested that PEP decreased as a result of treatment, and that social anxiety symptoms for individuals reporting greater levels of PEP improved at a slower rate than those with lower levels of PEP. Further research is needed to understand why PEP attenuates response to treatment.     

Virtual-reality distraction and cold-pressor pain tolerance: does avatar point of view matter?

This study tested the effects of distraction using virtual-reality (VR) technology on acute pain tolerance in young adults. Forty-one undergraduate students, aged 18-23 years, used a VR head-mounted display helmet, steering wheel, and foot pedal to play an auto racing video game while undergoing exposure to very cold water (cold pressor set at 1 °C). Two different game views were tested that were hypothesized to affect the degree to which participants felt "present" in the virtual environment: a first-person view, in which the participant saw the virtual environment through the eyes of the game character being manipulated; and a third-person view, in which the participant viewed the game character from a distance. The length of time participants tolerated the cold-water exposure (pain tolerance) under each distraction condition was compared to a baseline (no distraction) trial. Subjects also rated the degree to which they felt "present" in the virtual environment after each distraction trial. Results demonstrated that participants had significantly higher pain tolerance during both VR-distraction conditions relative to baseline (no distraction) trials. Although participants reported a greater sense of presence during the first-person condition than the third-person condition, pain-tolerance scores associated with the two distraction conditions did not differ. The types of VR applications in which presence may be more or less important are discussed.     

Mere presence is not enough: Responsive support in a virtual world

When individuals are faced with novel or threatening situations, the presence of a trusted companion should reduce anxiety and promote feelings of security. Attachment theory assumes, however, that mere presence is not sufficient for establishing security; an attachment figure must also be attentive and emotionally responsive. To test this idea, participants came to the lab with their romantic partner and completed a threatening cliff-walking task in a digital immersive virtual environment. The presence and nonverbal support behavior (attentive vs. inattentive) of their partner was experimentally manipulated. Results indicated that participants in the attentive-partner condition experienced the task as less stressful than those who were alone; they also reported feeling more secure during the task and were less vigilant of their partner's behavior compared to those in the inattentive-partner condition. Those in the inattentive-partner condition felt less cared for and kept greater physical distance from their partner on a subsequent task. These findings suggest that human beings are predisposed to monitor their social environment for signs of responsiveness, and that perceived responsiveness, not mere presence, is the key modulator of emotional security.     

Effects of perceived criticism on anxiety and depression during behavioral treatment of anxiety disorders

The present study explored the effect of perceived criticism (PC) on levels of anxiety and depression during behavioral treatment among patients diagnosed with obsessive-compulsive disorder (OCD) or panic disorder with agoraphobia (PDA). We posited that patients' perceptions of relatives' criticism and the degree to which they were upset by the criticism (UC) would be related to negative affect and discomfort during exposure. The sample included 75 patients with a primary diagnosis of OCD (n=43) or PDA (n=32) and their participating relatives. Measures of patients' weekly ratings of PC and upset about the criticism, anxious and depressed mood, and subjective discomfort during exposure treatment were analyzed using a mixed model regression approach (SAS Proc Mixed). Patients' anxious and depressed mood predicted greater discomfort during exposure. Patients who were more UC also had higher weekly ratings of anxiety and depression, and more discomfort during exposure sessions. Findings suggest that treatment outcome may be improved by attention to patients' reactions to their interpersonal environment.