Lighting and Spatial Proportions in Virtual Reality: Patterns of Comfort and Task Performance

This study investigates how spatial configuration and lighting conditions jointly influence comfort and task performance using an interactive virtual reality experiment. Forty-two participants experienced four spatial configurations (Base, Wide, High, and Deep) under two lighting conditions (2600K and 5200K) in a within-subject design. Perceptual comfort was assessed through in-VR questionnaires, and task performance was measured using four interactive tasks targeting sensorimotor speed, inhibitory control, working memory, and problem-solving ability. Results showed that vertically expanded spaces were perceived as less comfortable, particularly under cool lighting. Task performance exhibited task-specific sensitivity to spatial and lighting conditions. Inhibitory control was reduced in vertically expanded spaces, while working memory and problem-solving performance were enhanced under cool lighting in high and deep rooms. To examine comfort and task performance simultaneously, a multidimensional analysis was conducted using standardized z-score composites. This analysis revealed systematic patterns and trade-offs across conditions, with some conditions favoring comfort and others favoring task performance. Warm lighting in deep spaces supported relatively balanced outcomes, whereas cool lighting in vertically expanded spaces enhanced performance at the expense of comfort. These findings demonstrate that no single spatial or lighting condition uniformly optimizes both comfort and task performance. By adopting a multidimensional analytical framework, this study highlights the importance of jointly considering perceptual and performance outcomes when evaluating architectural and lighting design strategies.