Measuring the Impacts of Indoor Spatial Lighting Patterns and Correlated Color Temperature on Perception and Cognitive Performance of Older Adults

• Virtual reality closely replicated real-world lighting and cognitive responses • Spatial lighting and light color correlated with perception and cognitive performance in older adults • Nonuniform, peripheral, direct/indirect lighting increased comfort and reduced stress • Cool 5000 K light improved task speed but increased arousal and stress • Spatially varied lighting reduced cognitive errors compared with uniform lighting Human-Centric Lighting is a framework that integrates light levels, spectral power distribution, and temporal and spatial patterns to assess lighting’s visual and non-visual effects on occupants’ behavior and wellbeing. Despite its comprehensive application, most previous studies have focused on illumination and temporal parameters, yet the impact of indoor lighting spectral and spatial patterns on cognitive functioning remains underexplored, in general, and for older adults' environments in particular. This study examined how spatial lighting patterns (SLP) and correlated color temperature (CCT) affect perceptual and cognitive performance among older adults in an assisted living facility's general assembly room. A two-phase within-subjects counterbalanced design experiment was conducted with thirty-two old adult residents of the facility. Phase one evaluated the feasibility of using immersive virtual reality (VR) to simulate lighting conditions and measure cognitive task performance. Phase two used a validated VR environment and a 2×2 factorial design to test two SLPs (uniform/central/direct vs. non-uniform/peripheral/direct-indirect) and two CCTs (2700 K vs. 5000 K). Cognitive performance was assessed using the Trail-Making Task with accuracy and completion speed as outcome measures. Results showed strong associations between perceptual ratings and cognitive outcomes across real and VR settings, supporting the use of VR for lighting research. Non-uniform/peripheral/direct-indirect lighting was perceived as more pleasant, relaxing, and less stressful than uniform/central lighting, while 5000 K lighting improved cognitive accuracy and speed but increased arousal and reported stress. These findings expand the human-centric lighting framework by demonstrating how spatial and spectral attributes jointly influence perceptual and cognitive responses in aging populations.