When virtual reality becomes psychoneuroendocrine reality: A stress(or) review.

This review article was awarded the Dirk Hellhammer award from ISPNE in 2023. It explores the dynamic relationship between stressors and stress from a historical view as well as a vision towards the future of stress research via virtual reality (VR). We introduce the concept of a "syncytium," a permeable boundary that blurs the distinction between stress and stressor, in order to understand why the field of stress biology continues to inadequately measure stress alone as a proxy for the force of external stressors. Using Virtual Reality (VR) as an illustrative example to explicate the black box of stressors, we examine the distinction between 'immersion' and 'presence' as analogous terms for stressor and stress, respectively. We argue that the conventional psychological approaches to stress measurement and appraisal theory unfortunately fall short in quantifying the force of the stressor, leading to reverse causality fallacies. Further, the concept of affordances is introduced as an ecological or holistic tool to measure and design a stressor's force, bridging the gap between the external environment and an individual's physiological response to stress. Affordances also serve to ameliorate shortcomings in stress appraisal by integrating ecological interdependencies. By combining VR and psychobiological measures, this paper aims to unravel the complexity of the stressor-stress syncytium, highlighting the necessity of assessing both the internal and external facets to gain a holistic understanding of stress physiology and shift away from reverse causality reasoning. We find that the utility of VR extends beyond presence to include affordance-based measures of immersion, which can effectively model stressor force. Future research should prioritize the development of tools that can measure both immersion and presence, thereby providing a more comprehensive understanding of how external stressors interact with individual psychological states.

Evoking stress reactivity in virtual reality: A systematic review and meta-analysis.

BACKGROUND: Virtual reality (VR) research probes stress environments that are infeasible to create in the real world. However, because research simulations are applied to narrow populations, it remains unclear if VR simulations can stimulate a broadly applicable stress-response. This systematic review and meta-analysis was conducted on studies using VR stress tasks and biomarkers. METHODS: Included papers (N = 52) measured cortisol, heart rate (HR), galvanic skin response (GSR), systolic blood pressure (SBP), diastolic blood pressure (DBP), respiratory sinus arrhythmia (RSA), parasympathetic activity (RMSSD), sympathovagal balance (LF/HF), and/or salivary alpha-amylase (sAA). Effect sizes (ES) and confidence intervals (CI) were calculated based on standardized mean change of baseline-to-peak biomarker levels. RESULTS: From baseline-to-peak (ES, CI), analyses showed a statistically significant change in cortisol (0.56, 0.28-0.83), HR (0.68, 0.53-0.82), GSR (0.59, 0.36-0.82), SBP (.55, 0.19-0.90), DBP (.64, 0.23-1.05), RSA (-0.59, -0.88 to -0.30), and sAA (0.27, 0.092-0.45). There was no effect for RMSSD and LF/HF. CONCLUSION: VR stress tasks elicited a varied magnitude of physiological stress reactivity. VR may be an effective tool in stress research.