In this study, we evaluated the scent intensity, emotional response, and EEG response according to the concentration of bergamot scent inhaled by young women whose average age was 18, and analyzed the correlation between these factors. The correlation between bergamot concentration (P, vol %) and odor intensity (I) was [I] = 1.22 + 0.86P (r2 = 0.99). The scent intensity of bergamot was about 3.8. The emotional response to the scent of bergamot was rated as pleasant, fresh, refreshing and feminine. Inhaling bergamot decreased the α waves in the brain and increased the θ, β, and γ waves. Additionally, the edge frequencies of the SEF50 and SEF90 were increased by 0.14 Hz to 0.59 Hz and 0.75Hz to 1.26 Hz respectively by bergamot. The odor intensity (concentration) and emotional response regarding bergamot showed a weak correlation with the amount of change in the edge frequency (ΔSEF50 and ΔSEF90). These results suggest that bergamot is a refreshing, feminine fragrance with an arousing effect that activates the brain.

This study investigated the convergence of the QEEG and mood state changes in healthy females from late teens to twenties in relation to the inhalation of peppermint oil (peppermint) in different concentrations (0.1~100%). Brain activity upon stimulation by different concentrations was analyzed based on the RPVs and CVB (%), representing a rate of change compared with the background QEEG. Peppermint showed the effect of relaxation at low concentrations (0.1 and 1%) with increased θ and α waves and decreased β and γ waves. As the concentration of peppermint increases, the α wave decreases, and the θ, β and w waves increase, and there is an arousal effect. Peppermint was rated as having a refreshing, exhilarating, and intense smell. At a low concentration of 0.1%, peppermint chiefly produced a feeling of pleasantness, freshness and refreshment. However, the increase in peppermint concentration resulted in a masculine, exiting, and hard emotional response. As the concentration of peppermint increased, the odor intensity increased in a linearly. The amount of change (ΔSEF50 and ΔSEF90) in edge frequencies closely related to the activation and stress of the brain showed a positive correlation. Odor intensity has a stronger association with ΔSEF90, a stress-related brain wave indicator than with ΔSEF50, a brain activation-related indicator. In addition, both ΔSEF50 and ΔSEF90 showed a positive correlation with APIGF (feelrefreshing average preference index) and a negative correlation with APIAC (Active-Calm average preference) and APIAll (total average preference index). These findings indicate that (1) the correlation between odor intensity and stress and (2) the relationship between emotional and QEEG can be interpreted in terms of brain wave study.

This study investigated the convergence of the QEEG and mood state changes in healthy females from teens to twenties on the inhalation of jasmine oil in different concentrations (0.01~100%). Brain activity upon stimulation by different concentrations was analyzed based on the RPVs and CVB, representing a rate of change compared with the background QEEG. The emotions elicited through jasmine were evaluated on a 20-point scale. The result of this evaluation showed that jasmine deactivated fast alpha but activated theta. In addition, it provided evidence for changes in the frequency band according to concentration. As concentration increased, the effect of alpha inhibition decreased, while the effect of inhibition of the high frequency band (20~50 Hz) increased. SEF50 and SEF90, which indicate the state of arousal, decreased as the jasmine concentration increased. Furthermore, it was assessed as having a pleasant, feminine, fresh and soft odor. Therefore, this study suggested that the inhalation of jasmine oil affected brain wave activities and mood states.