Abstract
The effects of fragrances on human arousal are not well understood. The aim of the present investigation was to determine the influence of two monoterpenes, 1,8-cineol and (±)-linalool, on human sustained attention, physiological arousal and well-being. The substances, as well as appropriate placebos, were administered either by inhalation or by skin application to a total of 130 healthy subjects. We found that when the fragrances were applied to the skin 1,8-cineol improved speed of attentional performance in comparison to (±)-linalool, but not in comparison to peanut oil, which served as a placebo. Under the same conditions, 1,8-cineol increased respiration rate in comparison to both (±)-linalool and placebo. In the inhalation condition, neither attentional performance nor physiological arousal were affected by the fragrances, but both odorants influenced well-being, i.e., 1,8-cineol decreased activation and (±)-linalool increased it. In contrast, no such effects were observed in the skin application condition. Our results demonstrate that fragrances affect cognitive performance, physiological arousal and well-being as a function of the mode of administration.