To better understand how fragrance may enhance human health, this study examined psychophysiological responses to Japanese plum blossom fragrance. Although previous studies used essential oils or fragrance components, the present study measured the effects of floral scent naturally diffused by the plant itself to simulate the way we generally experience natural scent in everyday life. Subjects were Japanese males (n = 26), and the data collected included cerebral and autonomic nervous system activities, semantic differential (SD) scale, and profile of mood states (POMS). Exposure to the fragrance significantly activated the sympathetic nervous system and the cerebral areas related to movement, speech, and memory. SD scale and POMS results showed the fragrance evoked cheerful, exciting, and active images and changed mood states by enhancing vigor while suppressing feelings of depression. These findings indicate that contact with a floral scent such as plum blossom fragrance can improve mood states and may foster the brain functions of memory, speech, and movement, potentially leading to improvements in emotional health, depression, and memory disorders.
Hyunju Jo, Susan Rodiek, Eijiro Fujii, Yoshifumi Miyazaki, Bum-Jin Park and Seoung-Won Ann
Sin-Ae Park, Chorong Song, Ji-Young Choi, Ki-Cheol Son and Yoshifumi Miyazaki
The study’s objective was to investigate the effects of foliage plants on prefrontal cortex activity and subjective assessments of psychological relaxation. In a crossover experimental design, 24 male university students in their 20s observed a container with and without foliage plants for 3 minutes while oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex was continuously measured with a portable near-infrared (NIR) spectroscopy device. Afterward, subjective evaluations of emotions were obtained via two self-report questionnaires: a modified semantic differential (SD) method and the Profile of Mood State questionnaire (POMS). Oxy-Hb concentration in the right prefrontal cortex was significantly lower in subjects who viewed the foliage plants than in those who did not, indicating a physiologically relaxed state. The subjects also reported in the SD method significantly more positive emotions (e.g., comfortable, natural, and relaxed) associated with viewing the foliage plants. In the POMS, a significant positive effect on psychological relaxation when subjects viewed the foliage plants was shown. Thus, we conclude that foliage plants have both physiological and psychological relaxation effects in males even after only short exposure.