Meta-analysis: presence and anxiety are positively correlated in virtual reality exposure therapy

Considerable research focuses on enhancing the sense of being present in a virtual environment. But why, you might ask? Is this only for fun or does it also serve a therapeutic purpose? The latter seems to be the case. For virtual reality exposure therapy used to treat patients with anxiety disorders (e.g. fear of height, fear of flying, and social phobia), the feeling of presence correlates positively with the amount of anxiety experienced, a key ingredient for this type of therapy.

This conclusion is the main outcome of our meta-analysis published in PLoS ONE. In this study we included 33 articles that collected self-reported presence and anxiety data when a total of 1196 individuals were exposed in virtual reality environments specially selected to elicit anxiety. The aim of the anxiety elicitation in the virtual world is to enable patients get habituated to the thing they fear.

Besides an average correlation with a medium effect size, we also found a number of moderating factors that could influence the strength of this relationship. For example, we found variation between the types of anxiety disorders. Fear of animal studies reported large effect sizes whereas social anxiety studies reported no to small effect sizes. We also found the relationship to be stronger for patients than for non-patients. The meta-analysis also indicated that technology could be a moderating factor. Higher levels of immersive technology coincide with higher correlations between presence and anxiety. For example, the relationship was stronger in studies that used trackers with six degrees of freedom instead of three degrees of freedom. Also, increasing the field of view of displays coincided with a stronger relationship.

This put forward the dominance hypothesis of immersive technology. It suggests that advanced immersive technology dominates the relationship as it reduces the impact of other ‘noise’ factors such as individuals’ characteristics. For example, in the study we saw that the mediator factor of being a patient or not, disappeared in studies that used trackers with higher degree of freedom or displays with a larger field of view. In other words, where these more immersive technologies were used the feeling of presence was more able to explain whether an individual reported anxiety in the virtual environment.

In general the meta-analysis outcomes seems to warrant research in presence improvement, for example more immersive technology. For those interested, the whole study is freely available online.

Ling Y, Nefs HT, Morina N, Heynderickx I, Brinkman W-P (2014) A Meta-Analysis on the Relationship between Self-Reported Presence and Anxiety in Virtual Reality Exposure Therapy for Anxiety Disorders. PLoS ONE 9(5): e96144. doi:10.1371/journal.pone.0096144