Investigating a dose-response curve for daytime

Light can increase people’s alertness and cognitive performance, both during the night and day. However, most experiments on increasing alertness and performance have used a limited number of light levels, making it difficult to determine the optimal level for daytime situations. A dose-response curve has been established for nighttime exposure, but since melatonin secretion and homeostatic sleep pressure are higher during nighttime, this relationship cannot be generalized to diurnal conditions. The current study aimed at investigating the optimal light intensity to induce acute non-image forming effects of white light during the day. More specifically, we wanted to explore whether it would be possible to construct a dose-response curve for daytime light exposure, with respect to both subjective and objective indicators of alertness and cognitive performance. The results will be reported at the conference, but cannot be disclosed in this paper on account of a foreseen publication in a scientific journal.