The benefit of Daylight-Simulcasted Dynamic Lighting: An experiment isolating simultaneousness from dynamicity

Most people today stay in a constant artificial lighting environment for a long time. Lack of sufficient daylight exposure may lead to circadian, sleep or mental problem. Dynamic lighting is an effective countermeasure in consideration of its dynamicity. However, besides its changeability, whether the daylight simultaneousness of dynamic lighting has a beneficial effect is unclear. A lab-based study was carried out to explore the effect of Daylight-Simulcasted Dynamic Lighting (DSDL), which simulates the simultaneous information of daylight conveyed by its variation. A reversed pattern of DSDL (Re-DSDL) was also introduced as one of the test conditions for comparison. The within-subject experiment was performed by 24 participants in four conditions: two dynamic lighting patterns (DSDL and Re-DSDL) in two periods (dawn and dusk). The dependent variables were psychological states, physiological indicators and cognitive performance. The results showed that DSDL brought greater benefit to the psychological state than Re-DSDL in general. During dawn, participants experienced less anger and depression in DSDL than in Re-DSDL; during dusk, participants experienced less anger and vigour in DSDL than in Re-DSDL. DSDL also had a significant effect on some of the physical indicators compared with Re-DSDL, but no effect on cognitive performance.