Light in motion – Effects of dynamic and static light patterns from nature on subjective and physiological stress

• Effects of static vs dynamic light patterns from nature were tested on stress. • Restorative effects were tested across low-stress, high-stress, and recovery periods. • Dynamic condition led to lower skin conductance levels than control during the stressor task. • Dynamic patterns were appraised as more natural, engaging, complex, and distracting. • Insights support the use of nature-inspired dynamic light to enhance restorativeness. Daylight, and particularly sunlight, is widely regarded as a source of pleasure and a contributor to restoration indoors. The positive effects of daylight are often attributed to its unique spatial, spectral, and temporal dynamics. However, most research employs static representations of daylight, overlooking its dynamic character. The shadow and light patterns of trees swaying in the breeze are prominent examples of dynamic sunlight patterns we observe daily. The current study investigated, for the first time, the effects of such light pattern projections on subjective and physiological stress in an office setup. Seventy-three participants were assigned to one of three conditions (projections of dynamic light pattern, static light pattern, or uniform control condition) and performed tasks representing low-stress, high-stress, and rest periods. No effect of the condition was found for the low-stress and recovery periods. However, exposure to the dynamic condition during the high-stress period showed significantly lower skin conductance levels than the control condition, indicating a stress-dampening effect. Similar trends were observed in heart rate and heart rate variability but did not reach statistical significance, while no effects were found on subjective stress. The dynamic condition attracted more attention and was perceived as more natural than the static and control conditions. Additionally, it was rated higher in positive affect and engagement, complexity, and distraction than the control condition. The findings of this study suggest that dynamic sunlight patterns from nature could enhance the design of indoor environments with stress-dampening qualities.