NEUROPHYSIOLOGICAL RESPONSES TO VARIABLE LAVENDER FRAGNANCE CONCENTRATION: AN EEG AND SENSORY EVALUATION STUDY

This study aims to evaluate the impact of different concentrations of lavender fragrance on the nervous system, specifically identifying the threshold at which conscious perception of the scent ceases while the nervous system continues to respond. Thirty subjects participated in an olfactory task involving lavender essence diluted in alcohol at three concentrations (1%, 0.1%, and 0.01%). Data were collected using an eight-channel EEG device and a self-report questionnaire, processed with signal processing techniques (Fourier Transform and Ika), and analyzed using SPSS software with a focus on hemispheric asymmetry and alpha, beta, and theta frequencies. The findings reveal that fragrance concentration significantly affects brain electrical activity. Higher concentrations of lavender induced a more stressful effect on subjects, while the lowest concentration (0.01%) was most effective in promoting relaxation, as demonstrated by the largest deviation from the overall mean in the α/β ratio. This study highlights a significant inverse relationship between lavender concentration and its psychophysiological effects, with the minimal concentration proving particularly beneficial for inducing relaxation. These insights suggest that low concentrations of lavender fragrance could be effectively utilized in environments designed to promote well-being.