Orange-Sweet Scent Reduces Stress Associated with Numerical Tasks: A Physiological and Psychological Evaluation

Abstract: This paper evaluates the stress reduction effects of orange-sweet aroma at the perception threshold. The number of patients suffering from stress-related disorders is increasing, making it a significant social issue as stress can prevent individuals from working and interfere with their daily lives. However, completely eliminating stress from daily life is not feasible. Therefore, this research aims to identify a method for reducing stress within this social context, even when stress is present. Given the varying influence of scents on individuals, this study examines the stress-reducing effects of orange sweet essential oil aroma at the perception threshold. A sample of 20 university students (10 males and 10 females; average age 22 years) participates in the study. The experiment is conducted under two conditions: with and without the scent. The stress task, designed to eliminate the influence of computational ability, involves simple numerical computations performed under both conditions. To evaluate the effects of the aroma on stress reduction, multiple physiological and psychological indices are utilized. Physiological indices include electrodermal activity (EDA) and salivary amylase levels. Psychological indices include the short version of the Profile of Mood States 2 (POMS2), a Japanese questionnaire for work-related fatigue feelings called Jikakusho-shirabe, and a Likert scale questionnaire assessing scent preference and intensity. Electrodermal activity (EDA) significantly increased during the stress task compared to the rest condition. Additionally, the discomfort factor in the Jikakusho-shirabe increased after the task compared to before the task, but only in the absence of aroma. These results indicate that the stress task created in this study effectively induces arousal. Furthermore, the findings suggest that discomfort can potentially be reduced by the presence of orange-sweet scent at the perception threshold. However, the presence of aroma resulted in a significant difference only in the discomfort factor. In future experiments, we will focus on behavioral indices, such as poor performance, which cannot be determined solely by physiological or psychological indices.

Keywords: Subjective scaling, electrodermal activity, EDA, jikakusho-shirabe, POMS2, and salivary amylase

DOI: 10.54941/ahfe1005689

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