Aroma is considered to have a close relationship to meditation. Very sensitive people describe that they have had a meditation-like experience when they smell some kinds of fragrances. The author has already reported that the EEG of a Koh (traditional Japanese incense) master immersed herself in incense was quite similar to that during meditation found in a Buddhist priest or a Qigong master. In this report, characteristics of EEG changes during smelling were analyzed in relation to those during meditation. EEGs of 15 subjects who were regarded to be
sensitive to smell, for instance aroma therapists or persons who had usually been in contact with aromas, were measured and compared with those of several specialists in aroma, such as perfumes and Japanese Koh masters, and with EEGs of 44 ordinary students. Essential oils used for the 15 subjects were as follows: lemon, lavender, patchouli, marjoram, rosemary and sandalwood. As a control, EEGs in the resting state with eyes closed, while listening to classical and rap music and doing a mental calculation were measured. Amplitude of ¶ waves on the occipital area, an indicator of relaxation, did not increase while smelling the oils, but it was a little larger in the subjects who had more experience in aromas than in less experienced persons. The ¶ waves, which distinctively appear on the frontal area during meditation, were not clearly observed in the subjects. On the other hand, lag time of the ¶ phase between the occipital and frontal areas, an indicator of concentration, was much shorter for less experienced subjects than experienced ones. The less experienced subjects seemed to concentrate on smelling, while the more sensitive and experienced subjects tended to be free of their thoughts.

Study of EEGs on the effects of aromas in comparison with EEGs during meditation