Title: Transferral of postural and emotional adaptation from virtual to real heights
Thesis Supervisor: Dr. Mark Carpenter
Committee members: Dr. J. Timothy Inglis, Dr. Romeo Chua
Defence Chair: Dr. Hyosub Kim
Abstract: Virtual Reality (VR) has demonstrated utility in examining postural adjustments linked to fear, anxiety, and confidence under different types of perturbations. However, whether the emotional and postural adaptations learned in VR can be transferred to real scenarios is unknown. Therefore, this study explored the adaptation of emotional state and standing balance measures following repeated exposure to a virtual height and subsequent transferal to standing at real heights.
Thirty-two healthy young adults participated in this study. Participants were randomly assigned to either a VR or Control group. All participants visited the lab on two separate sessions, with 24 to 48-hour intervals between sessions. Participants in the VR group were trained to perform quiet standing tasks repeatedly under HIGH conditions (3.2 m) in a VR environment during their first visit. Meanwhile, the Control group participants performed the same number of standing trials in a real laboratory environment under LOW conditions (0.8 m) only. During the second visit, both groups repeatedly stood quietly on a real elevating platform set at Low (0.8m) and High (3.2m) heights. In all conditions emotional state was assessed using self-report questionnaires and electrodermal activity measures. Balance was assessed using forceplate-derived center of pressure (COP) summary measures to characterize the amplitude, frequency and mean position of postural sway. Muscle activity was assessed using electromyography, with co-contraction of the Tibialis Anterior (TA) and Soleus (SOL) calculated via a custom script.
The results demonstrated threat-related changes in emotional state in the VR group, that adapted to near-baseline levels over the course of repeated trials of standing at virtual height; similar changes were not observed in the Control group. When standing on a real platform (visit 2), both groups demonstrated increases in fear, anxiety, arousal, decreases in balance confidence, and changes in attentional focus, in the High compared to Low conditions. However, significant main effects of group indicated smaller threat-related changes in emotional state were observed in the VR group compared to Controls. Although not all standing balance outcomes showed significant group differences, VR Group participants exhibited a smaller backward lean compared to Controls when standing in the High condition. These results indicate that VR can be an effective tool for eliciting and training participants’ emotional responses and some threat-related postural strategies, particularly in height-related scenarios.