Virtual Reality for Human-Centred Evaluation of Underground Environments: A Focused Review

Underground spaces are becoming increasingly important in high-density urban environments, yet their restricted sensory conditions, limited natural references, and distinctive spatial characteristics make human responses difficult to evaluate. Virtual reality (VR) provides a controlled platform for investigating perception, cognition, and emotion in underground environments. This review synthesizes a focused body of evidence at the intersection of VR-based simulation, underground environments, and human-response assessment. A corpus of 28 studies was analysed using qualitative coding and evidence mapping. Environmental variables were organised into six categories, and reported outcomes were interpreted through a perception cognition emotion (PCE) framework. The reviewed studies show that visual conditions and biophilic interventions are frequently associated with perceptual, cognitive, and emotional outcomes, while wayfinding-related factors are most commonly represented in cognitive outcomes involving orientation, route choice, and decision-making under uncertainty or stress. The evidence also reveals a strong methodological emphasis on visually oriented and single-factor experimental designs, while multi-factor interactions and non-visual environmental influences remain comparatively underexplored. By providing a structured synthesis of current evidence, this review highlights methodological characteristics, identifies research gaps, and offers directions for future VR-based underground-environment research and human-centred design.