Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.792944
Title: Deepening extinction in a virtual reality treatment for fear of heights
Author: McInerney, Josephine
ISNI:       0000 0004 8500 881X
Awarding Body: Royal Holloway, University of London
Current Institution: Royal Holloway, University of London
Date of Award: 2019
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Abstract:
Fear of heights was one of the first phobias to be treated using virtual reality and has since developed a substantial evidence base. Post treatment effect sizes have consistently been medium to large and it is as effective as in vivo exposure. Virtual reality treatments are being disseminated into clinics, but many continue to use hierarchical exposure models that rely on habituation as the primary mechanism of change. Exposure does not work for everyone and fear renewal is common. The inhibitory learning model consolidates the research on fear extinction and makes a series of recommendations to maximise exposure. These include deepening extinction (combining phobic cues), violating expectancy (predicted verses actual outcomes), removal of safety signals (dropping safety behaviours), variability (varying exposure intensity) and using multiple contexts for exposure. Virtual reality provides a unique platform to investigate individual components of exposure treatments as scenarios are easily adapted and experimental conditions can be maintained. There is limited evidence examining treatment mediators and moderators of virtual reality exposure and few studies have compared treatments to investigate augmentations. Physiological arousal is associated with fear responses to phobic stimuli. However, there is often discordance between subjective and objective measures of anxiety in both virtual reality and in the real world. Some people with a fear of heights misinterpret anxious arousal as threatening and believe it will increase the likelihood of falling. A number of studies have measured physiological responses, but few have manipulated arousal. The evidence for predictors of treatment outcome in specific phobias is inconclusive. There is some support for an association between state and trait anxiety in spider phobics. Likewise, negative cognitive style and low mood has been found to lead to poorer outcomes. Safety seeking behaviours are key maintenance factors in anxiety disorders and are central to exposure therapies for phobias. Aversion to risk has not been investigated in this population but avoidance is a primary safety behaviour that minimises the potential for harm. Therefore, it is possible that this contributes to treatment outcome. As new treatments are developed and automated, it is important to understand predictors of outcome to ensure therapeutic content is appropriately designed. Aims The aim of the empirical study is to investigate whether deepening extinction by increasing physiological arousal in an automated virtual reality treatment for fear of heights enhances cognitive change. The primary hypothesis was that deepening extinction by increasing physiological arousal in virtual reality would significantly reduce belief conviction in comparison to virtual reality alone. The secondary hypothesis was that self-efficacy and subjective units of distress would mediate the effect of increased physiological arousal on belief conviction. The final hypothesis was that tendency to use safety behaviours, risk aversion, mood, trait anxiety, sensitivity to internal phobic cues and self-reported fear of heights are predictors of overall belief reduction in virtual reality exposure therapy. The main finding that physiological arousal was not associated with conviction change indicates that deepening extinction does not provided added benefit to exposure treatments and that arousal is not required to achieve cognitive change in virtual reality. One explanation for these findings is that only participants with certain fears about heights such as, losing balance or being out of control, appraised physiological arousal as threatening. It is also possible that deepening exposure was more robust to fear renewal, which this study was not designed to detect as there were no follow up measures. The improvement in self-efficacy across all participants suggests further research is warranted to investigate feelings self-efficacy as a mechanism of change in virtual reality treatments. It is also recommended that researchers consider alternative methods of increasing arousal such as, mental imagery. Research examining the differences between subgroups of height phobics based on threat beliefs is also indicated.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (D.Clin.Psy.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.792944  DOI: Not available
Keywords: Virtual Reality ; Fear of heights
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