The impact of color correlated temperature and illuminance levels of office lighting on stress and cognitive restoration

Abstract

In modern workplaces, the well-being and productivity of employees are increasingly recognized as essential for organizational success. This study explores the impact of lighting interventions—specifically, Correlated Color Temperature (CCT) and illumination intensity—on stress and cognitive function restoration among office workers. A between-subjects experimental design involving 100 participants assessed the effects of various lighting conditions on stress responses and cognitive performance after exposure to stress-inducing and cognitive fatigue tasks. Five experimental conditions were studied: 100 lux & 7000 K, 100 lux & 3000 K, 1000 lux & 7000 K, 1000 lux & 3000 K, and a baseline condition of 500 lux at 3700 K. Results indicated that lighting conditions significantly influence both physiological stress markers (such as skin conductance level and heart rate) and cognitive performance. Specifically, warm, and dimmed lighting (3000 K, 100 lux) effectively reduced stress markers and perceived stress levels, aligning with theories suggesting the calming effects of warmer white light tones. Conversely, cooler lighting (7000 K) was associated with enhanced cognitive performance and reduced cognitive fatigue, potentially due to its similarity to natural daylight, stimulating an alert state conducive to mental tasks. These findings suggest that lighting interventions offer a non-intrusive strategy to improve well-being and productivity in office environments, particularly addressing acute symptoms.