Effects of the Essential Oils of Sweet Orange, Lavender and Amyris on EEG Activity

Abstract

Purpose: This study evaluated the effects of the mixed essential oils containing sweet orange, lavender, and amyris (MEO) on human electroencephalogram (EEG) activity.Methods: EEG activity was recorded by examining the sequence of brain waves of 20 adults, aged from 20 to 30, before and during inhaling the mixed essential oils.Results: MEO showed activity centered on the frontal lobe, which is responsible for higher-order functions against external stimuli, and this result indicated that the oils acted as an intellectual effect. Additional experiments showed that the brain was relaxed and stabilized through a decrease in the absolute slow alpha (ASA) and the relative slow alpha (RSA), a decrease in the absolute beta (AB) and the absolute high beta (AHB), and an increase in the spectral edge frequency 50% of alpha (ASEF), respectively. Also, the oils induced the awakening states of the brain with a decrease in the absolute alpha (AA) and the absolute theta (AT), and increase of the spectral edge frequency 50% (SEF50). Furthermore, it was possible to confirm the state of brain immersion through the increase in the absolute fast alpha (AFA), relative fast alpha (RFA), relative mid beta (RMB), ratio of mid beta to theta (RMT), ratio of SMR to theta (RSMT), relative gamma (RG) and the spectral edge frequency 90% (SEF90).Conclusion: Taken together, these results suggest that the inhaling of MEO affect the brain to be a good condition and improves its concentration ability.