Effects of Human-Centric Lighting on Performance in the Attentional Network Test (ANT) and on Perceived Stress

The short-term effects of light on cognitive processes within the framework of Human Centric Lighting (HCL) remain underexplored and show inconsistent findings. In a laboratory study involving 789 participants, the influence of bright daylight white (BL), warm white (WL), and neutral light on executive functions was investigated using the Attention Network Test (ANT). BL emerged as the most beneficial condition overall, particularly enhancing the alerting component. In contrast, WL was repeatedly associated with negative effects on both alerting and executive attention. Unexpectedly, WL showed advantages in the orienting component, suggesting complex underlying mechanisms that are not yet fully understood. Future studies should examine lighting programs with greater contrast and incorporate physiological measures (e.g., pupillometry, EEG) as well as more differentiated psychological assessments. To explain these findings, the development of integrative models--such as the HCL-effect model proposed by Wessolowski--is essential. Light is more than a visual stimulus; it modulates attention and cognition. This insight should be systematically considered in the design of work, learning, and living environments.