The Potential of Olfactory Stimuli in Stress Reduction through Virtual Reality

TL;DR

This study investigates how adding olfactory stimuli to virtual reality environments can enhance relaxation and stress reduction, with physiological evidence supporting its effectiveness and potential for practical use.

Contribution

It provides empirical evidence that olfactory stimuli can significantly improve physiological relaxation responses in VR, highlighting multisensory integration's role in stress reduction.

Findings

Olfactory stimuli increased heart rate variability (HRV) significantly.

Self-reported relaxation scores showed no significant difference.

Majority of participants are willing to use olfactory-enhanced VR for relaxation.

Abstract

Immersive virtual reality (VR) is a promising tool for stress reduction and relaxation, traditionally relying on visual and auditory stimuli. This study examines the role of olfactory stimuli in enhancing these effects, using a randomized within-subject design. Thirty participants aged 18-60 experienced VR scenarios simulating a calming seaside environment, with sessions lasting 45 minutes, in two conditions: with and without a "Beach" essential oil scent (Yankee Candle) administered via diffuser. Stress and relaxation were assessed through self-reported surveys and physiological measures, specifically ECG-based heart rate variability (HRV). Results showed no significant difference in self-reported relaxation scores (p=0.371) between conditions, but HRV analysis revealed a significant stress reduction (p=0.002) with olfactory input, with HF increasing 108% from the Math Stress Test to the scented relaxation condition, compared to 44% without scent. Additionally, 71.4% of participants expressed willingness to use olfactory-enhanced VR for relaxation, suggesting practical appeal. These findings indicate that olfactory stimuli may enhance relaxation subconsciously, underscoring the importance of multisensory integration in VR. Future work could explore personalized scents and long-term effects to optimize VR- based interventions for emotional and physical well-being.