Daylight Timing and Natural Scent on Cognitive Performance in Office Settings

¹ School of Civil, Environmental and Sustainable Engineering, Arizona State University, Tempe, AZ 85281, USA
² School of Architecture , Clemson University, Clemson, SC 29634, USA
³ School of Sustainable Engineering and the Built Environment , Arizona State University, Tempe, AZ, 85281
⁴ School of Sustainable Engineering and the Built Environment , Arizona State University, Tempe, AZ, 85281

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Abstract

The role of multisensory environments in supporting human performance has become a growing focus in indoor environmental quality (IEQ) research. This study examines the combined effects of daylight timing and natural scents on cognitive performance in office settings. A controlled experiment exposed participants to morning and afternoon daylight conditions combined with rosemary or frankincense scent, while environmental variables such as illuminance (lux), correlated color temperature (CCT), equivalent melanopic lux (EML), indoor air quality (IAQ), and thermal conditions were continuously monitored to ensure stable indoor conditions. Cognitive performance was assessed using the Joggle Research battery of eight validated digital behavioral tasks covering attention, memory, sensorimotor and processing speed, reasoning and executive function, spatial skills, risk taking, and sustained vigilance. Physiological responses were recorded with a wrist-worn wearable; among physiological measures, this conference paper reports only skin temperature. Other dependent variables (heart rate, heart rate variability, electrodermal activity [EDA], and EEG [alpha peak]), along with the full set of survey results on comfort and well-being, will be reported in a forthcoming journal article. A small subset of subjective IEQ ratings (daylight, air quality, thermal comfort) is reported here. The study explores whether rosemary in the morning and frankincense in the afternoon provide cognitive benefits compared to using scents without regard to timing. Joggle Research showed a significant scent x time interaction: in the morning, performance was similar for both scents, whereas in the afternoon frankincense produced significantly higher scores than rosemary. Skin temperature was higher with frankincense in both morning and afternoon. Together, these findings suggest that the type and timing of scent use influence cognitive outcomes, with certain scent-time combinations being more effective in supporting cognitive performance than using scents at random times of day. These results point to the importance of considering when scents are used in relation to daylight exposure in office environments. By showing how sensory factors interact to influence cognitive performance, this study adds to current understanding of multisensory IEQ strategies and may inform workplace design practices that support productivity and well-being in everyday workplace environments.