Effectiveness of Virtual Reality in Social Anxiety

Can Virtual Reality Effectively Elicit Distress Associated with Social Anxiety Disorder?

Social Anxiety Disorder (SAD) is characterized by significantly impairing and burdensome social distress, avoidance, and in some cases a deficit in social skill (Liebowitz et al. 1985; Patel et al. 2002; Turner et al. 1986; Wittchen and Beloch 1996; Zhang et al. 2004). Among the most commonly avoided situations (e.g., attending parties, meeting new people, using public restrooms, and speaking up in class or at meetings), the most prevalent is public speaking (Mannuzza et al. 1995; Stein et al. 1996). Currently, exposure therapy (EXP) utilizing in vivo stimuli is considered the most effective treatment for anxiety disorders such as SAD (Craske et al. 2008). However, in vivo exposure is not always practical or ethical, especially when the stimuli are dangerous, difficult to recreate or repeat (e.g., giving a speech in front of a full auditorium), prohibitively expensive (e.g., flight phobia), or elicit such intense fear that a patient is unwilling to enter therapy.

To address these limitations, virtual reality exposure therapy (VRET) was developed as a potential alternative to imaginal or in vivo exposure (Krijn et al. 2004; Rothbaum and Hodges 1999) and data suggest that VR may be a viable tool for the treatment of specific phobias and SAD, including public speaking anxiety (Anderson et al. 2003, 2005; Harris et al. 2002; Klinger et al. 2005; Wiederhold and Wiederhold 1998). However, efficacious methods of exposure therapy must meet certain underlying tenets and to date, few data have examined the match between those conditions and VRET. Foa and Kozak (1986) proposed the theory of emotional processing as the mechanism by which exposure therapy produces emotional and behavioral change. Emotional processing theory postulates that fear occurs when neural networks, which produce information about a stimulus (a situation or event), the meaning of that stimulus (threat or danger) and behavior (escape or avoidance, are activated. Exposure therapy alters these relationships by producing new and incompatible information/networks (see also Craske et al. 2008). Thus, to be consistent with the principles of emotional processing theory, VRET must meet three conditions. First, the virtual environment must be generalizable to real-life situations so that when extinction occurs in the virtual environment, there is a decrease in distress and avoidance in the corresponding real-life situation. Second, the patient must feel immersed (presence) in the environment as opposed to a passive observer (Slater et al. 1999). Finally, the virtual environment should elicit physiological arousal, which indicate that the core elements of the fear are being addressed (North et al. 1998; Regenbrecht et al. 1998; Schuemie et al. 2000). The second and third conditions are closely related as presence or engagement in a fear-eliciting environment should result in physiological arousal and subjective distress (Lee 2004; Schubert et al. 2001). However, previous trials, while suggesting that VR elicited physiological arousal (e.g., blood pressure and heart rate), self-reported distress and a sense of immersion were limited by small sample sizes, lack of a clinical population, and the lack of a comparable control task (i.e., the VR condition was not compared to an in vivo speech (Hartanto et al. 2014; Kotlyar et al. 2008; Pertaub et al. 2002; Slater et al. 2006)). One recent trial did demonstrate the ability of a VR conversation task to elicit significant levels of subjective distress and immersion when compared to a similar in vivo task (Powers et al. 2013); however, this study lacked the inclusion of a clinical population and objective measures of anxiety, thus its relevance to the treatment of a phobic population is unclear.

VRET has the potential to become a cost-effective, practical, and efficacious treatment for SAD, as it appears to appeal to a significant proportion of individuals with SAD (76 %) who chose it over in vivo exposure (Garcia-Palacios et al. 2007). Given the high prevalence of SAD, low rates of treatment seeking, and difficulty in constructing appropriate in vivo exposure conditions for people with SAD (e.g., difficulty finding audience members), the development of VR has the potential to alleviate the burden this disorder places on the individual, clinicians, and the economy. However, prior to its wholesale adoption, questions about VR s ability to satisfy Foa and Kozak (1986) basic requirements for emotional processing theory remain. This study will extend previous research in two ways. First, in order to examine VR s ability to elicit physiological arousal, subjective distress, and feelings of presence similar to in vivo exposure, this study compared a VR public speaking environment and a comparable in vivo speech task in individuals with SAD and individuals with no disorder. We hypothesized that when placed in a virtual environment and asked to give a speech, all participants would experience significantly increased physiological response and subjective distress over baseline resting conditions. Additionally, we hypothesized that individuals with SAD would have a greater increase in physiological and self-reported arousal during the in vivo speech task than the VR speech task. Finally, we predicted that individuals with SAD would experience greater changes in physiological and self-reported arousal during each of the speech tasks in comparison to healthy controls. In regards to presence, we hypothesized that all participants would feel present during both speech tasks, but more so during the in vivo speech task.

The first aim of the study was to determine whether a VR speech environment was capable of eliciting presence, physiological arousal and subjective distress in adults, in accordance with the tenets of emotional processing theory. Consistent with the findings of Slater et al (2006) and Kotlyar et al. (2008), the VR speech task produced a moderate level of immersion and elicited physiological arousal and distress. Specifically, despite reporting only partial engagement and presence in the VR environment, participants still experienced significantly elevated arousal (HR, RSA, SCL) and emotional reactivity (SCRs) relative to baseline. On a subjective distress scale of 0 to 8, the average score for subjective distress was 4.62 for participants with SAD, indicating a moderate degree of distress. The results suggest that VR shared sufficient similarities to a real life emotionally arousing event, supporting its utility as a tool for conducting exposure therapy. Although the lack of intense physiological arousal may be viewed as limiting, recent research suggests that full immersion with exposure stimuli may not always be necessary for desirable outcomes (Podina et al. 2013), although further studies are needed. It is notable that participants reported a greater sense of presence and during the in vivo speech task when the VR task was presented first. Although one can only speculate as to the reason for these findings, one possibility is a simple contrast effect. Actual individuals are more salient after being exposed to computer avatars.

Participants judged the VR environment to be less immersive than real life. One explanation for the attenuated feelings of immersion may be specific to its virtual nature. Specifically, the VR environment may not sufficiently address a primary concern of people with SAD fear of negative evaluation by others. For example, following the VR speech task, a number of participants remarked to the investigator, That wasn t nearly as scary as giving a speech with real people, you know that the virtual people aren t thinking negatively about you. As the current VR utilized an audience with neutral facial expressions, future investigations might consider several ways to increase immersion. Engagement and realism could be increased if the facial expressions were negative or at least varied in emotion or changed based on the participant s performance (Pertaub et al. 2002). Immersion may be enhanced if the virtual audience is able to react to the participant s actions (e.g., hand movements, posture, vocal quality) and emotional state. The lack of intense immersion (or feelings of reality) is not necessarily limited to public speaking environments. Similar difficulties and need for increased realism may be encountered with other VREs as well. For example, when conducting exposure therapy using an airplane VRE, an individual with flight phobia knows they are not in an actual plane but as noted above, less than intense physiological responses may still produce a clinically significant outcome.

clinically significant outcome. Whether assessed by subjective distress (SUDS ratings) or physiological response (HR, RSA, and SCR), VR elicited significant increases in arousal but less than an in vivo speech task. This finding suggests that although VR appears to be effective in reproducing the phobic stimulus, resulting in increased physiological and subjective distress, it is not equivalent to an in vivo speech task. Therefore, VR may be most efficacious as an intermediate treatment step, or as the ultimate in-clinic exposure exercise when clinician constructed in vivo exposure is not feasible. Furthermore, the higher percentage of escape behavior during the in vivo speech task for individuals with SAD suggests that, the VR speech task may be a useful first step for those who are initially unwilling to engage with in vivo exposures (Garcia-Palacios et al. 2007) and for those who have difficulty engaging with imaginal exposure. Therefore, it appears VR has the potential to alleviate the burden that SAD exposure therapy places on the individual and clinicians but is not a perfect substitution for engaging in the behavior in front of a live audience

Finally, the results did not reveal differences in physiological arousal between participants with SAD and controls; against the predicted outcome, there were no significant group differences in terms of autonomic arousal. While this finding may be reflective of the widespread nature of public speaking fears amongst even healthy individuals, Slater et al. (2006) reported significant differences in HR between Phobic and Confident Speakers. The lack of differences in the current study may be explained by the participant s opportunity for escape after only 3 min engagement in the task. For example, significant group differences in physiological arousal were found in a similar study in which participants were not given the opportunity to escape a 5-min in vivo speech task (Beidel et al. 1985). In that investigation both groups demonstrated a significant increase in physiological arousal; however, across the 5 min, controls habituated to the task, whereas arousal and distress in the socially anxious participants persisted. In contrast, allowing participants in the current study to escape, while allowing for an assessment of escape behavior, may have prevented group differences from emerging.

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