Vol. 56,  No. 2, pp. 93-102, Apr.  2019
10.12772/TSE.2019.56.093

Microcapsule Chamaecyparis obtusa essential oil fragrance intensity color tone EEG subjective sensibility

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The purpose of this study is to investigate the differences of EEG and subjective sensibilities of cotton knitted fabrics treated by microencapsules, including Chamaecyparis obtusa essential oil, based on fragrance intensity and color tone. Six specimens were prepared by dyeing a cotton knit in three different greenish-colored tones (strong, pale, and grayish). Next, the cotton knit was treated with microencapsules, thereafter generating two different levels of fragrance intensities using a crockmeter, namely, low intensity by onereciprocal friction and high intensity by ten-reciprocal friction. At low fragrance intensity, the SMR and beta waves increased more in the grayish tone than in the pale and strong tones, and its EEG signals were more activated by the grayish tone in most areas of the brain than by the pale and strong tones. For the subjective sensibilities, at low fragrance intensity, the grayish tone was evaluated as stronger in fragrance than the strong and pale tones. At high fragrance intensity, the alpha and SMR waves increased more in the strong tone than in the pale and grayish tones, and the EEG signals were more activated by the strong tone in most cites of the cerebrum than by the pale and grayish tones. For the subjective sensibilities, at high fragrance intensity, the strong tone was assessed to have a more comfortable and natural fragrance than the pale and grayish tones. For both EEG and subjective sensibility, the fragrance intensity and color tone interacted significantly with each other. Considering psychophysiological aspects, the alpha waves increased in the grayish tone at high fragrance intensity among the cotton knitted fabrics preferred in the subjective evaluation, and the SMR waves increased in the strong tone at high fragrance intensity. Therefore, it is necessary to consider both fragrance intensity and color tone depending on the purpose of product development.