Discussion
affirmative head nods, affirmative head nods increase
DISORDERS
Virtual coaches are a key element in automated VR therapies for mental health disorders. We investigated whether introducing positive non-verbal behaviours to the coach increased the therapeutic alliance and treatment credibility and expectancy. Our results partly support our initial hypotheses. We hypothesised that warm facial expressions and affirmative head nods would enhance the therapeutic alliance, treatment credibility, and expectancy, and their combination would have the strongest impact. The results showed that warm facial expressions and affirmative head nods individually affected therapeutic alliance, and the impact of warm facial expressions was more substantial. Additionally, affirmative head nods increased people’s beliefs in both the credibility of the treatment and the expectancy of good outcomes. Although there was no significant interaction between warm facial expressions and affirmative head nods, there was a trend in the direction that the combination led to greater treatment credibility. In essence, how a virtual coach is programmed affects the treatment experience and potentially therapeutic outcomes. In this study we showed that there is likely to be value in implementing facial expressions and positive non-verbal behaviours for the virtual coach.The primary finding that warm facial expressions and affirmative head nods increase alliance is in line with previous studies of virtual humans outside of the context of VR mental health treatmentOur main focus was the effect of characteristics of a coach on established proxies for good therapeutic outcomes. But we also took an exploratory look at potential effects on participants’ behaviours in relation to virtual heights. Approximately one-third of participants did not complete the circuit out to the virtual height and back again. There was no significant difference in the task completion rate, or the distance covered, between the groups allocated to different virtual coach conditions. Since this was the participants' initial exposure to virtual heights, as opposed to the multiple immersions experienced during a full therapy session, we did not make any specific predictions. It would be plausible that the relationship with the virtual coach would make no noticeable difference as patients obtain their first experience of the treatment technique. Indeed, no group differences were detected in whether a person stepped onto the platform or the distance covered.The study has several limitations. First, we do not know whether the effects of the non-verbal behaviours do translate to better outcomes. This would require a clinical trial to provide evidence. Our view is that using proxies of good outcomes such as therapeutic alliance and treatment credibility is a more sensible testing strategy than conducting multiple clinical trials on small changes to a programme. When such treatments get used at scale then it may be possible to look at outcome effects by programming modifications. Second, we only focused on the virtual coach’s facial expressions and head nods and did not account for factors such as gender, ethnicity, and age of the participants. Previous research indicates that people tend to have stronger bonds with virtual humans with similar characteristics as the personIn this study we investigated the effects of a virtual coach's positive non-verbal behaviours during an automated VR consultation for the treatment of the fear of heights. The inclusion of warm facial expressions and affirmative head nods independently increased therapeutic alliance. Furthermore, affirmative head nods by the virtual coach improved perceptions of treatment credibility and positive outcome expectancy. The findings highlight the potential to enhance the experience and effectiveness of VR therapies through tailored VR character design. While our study focused on the cognitive treatment of fear of heights, further study is needed to examine the degree to which there is generalization to other mental health difficulties and different treatment techniques. The development of VR therapies would benefit from a systematic programme of research of the best attributes of virtual coaches, which may vary depending on the conditions and treatment techniques, and require strong collaborations between clinical staff, people with lived experiences, and software developers.