The impact of digital scents on behavioral health in a restorative virtual reality environment

Abstract

Astronauts on long-duration missions are at an increased risk of developing adverse behavioral conditions due to prolonged periods in isolated, confined, and extreme (ICE) environments. Sleep loss, sensory deprivation and monotony, and loss in social connectedness can further exacerbate their conditions and decrement performance, thus jeopardizing mission success. Future missions will require crews to travel distances that make current countermeasures increasingly difficult, as they rely on proximity to Earth. We have developed a multi-sensory virtual reality (VR) environment as a potential tool to maintain the long-term behavioral health of astronauts. We conducted a within-subjects study (N = 10) to compare the effectiveness of our VR environment with and without the incorporation of digital scents. Prior to the VR experience, subjects completed a public speaking task to elevate stress levels and emulate the stressful conditions that astronauts might encounter on a mission. The virtual nature environment features a small, forested area with localized scents that are dispersed based on the user's location in the VR environment. For example, floral scents were emitted when the user was near the field of flowers. The Positive and Negative Affect Schedule (PANAS) and the 6-item State-Trait Anxiety Inventory (STAI-6) questionnaires were administered to record subjective data on the participant's state affect and anxiety throughout the experiment. Participants reported significantly lower STAI-6 scores after the VR experience when scents were present than in the control condition (p = 0.03). Compared to the stressed state, PANAS Negative Affect (p = 0.003) and STAI-6 (p = 0.001) scores decreased after the VR with scents condition. STAI-6 scores (p = 0.013) also decreased from baseline when olfactory stimuli were added. These results suggest that the addition of olfactory stimuli to the VR environment aided in reducing negative affect and state anxiety levels. In addition, our results indicate that the use of multisensory VR environments are a promising countermeasure to support behavioral health during long-duration exploration missions.