Abstract
Postural threat influences standing balance control, yet only some of these changes are attenuated with repeated exposure to the threat (Johnson et al. 2019; Zaback et al. 2019). This study used virtual reality to repeatedly expose subjects to a height-induced postural threat to determine if similar emotional and postural changes are observed. We hypothesized that repeated exposure to a virtual-height would minimize the emotional response, however, most threat-related balance control changes would remain unchanged. Seven healthy young adults (6 females) completed a series of 60-s quiet standing trials while wearing a head-mounted display and immersed in a virtual lab standing on a "Low" height ( 0.8m above ground, away from the platform edge; 2 trials) and "High" platform (3.2m above ground, at platform edge; 15 trials). Each trial was followed by a seated rest. Fear of falling, perceived anxiety and confidence, and attentional focus were measured using questionnaires. Electrodermal activity (arousal) and forceplate-derived centre of pressure (COP) measures were recorded for each trial. Fear, anxiety, confidence, arousal, and attentional focus all significantly changed with initial exposure to a virtual-height and were subsequently attenuated following repeated exposure. In contrast, most height-related changes in balance control did not adapt with repeated exposure. These results suggest that some threat-related postural changes are context dependent, and repeated exposure to virtual heights can be used to examine relationships between emotional state, attentional focus, and postural control.Acknowledgments: Funded by NSERC