title: The effects of lavender oil inhalation on emotional states, autonomic nervous system, and brain electrical activity.
abstract: OBJECTIVE
  Investigate the effects of lavender oil on the central nervous system, autonomic nervous system, and mood responses in humans after inhalation.
  
  
  METHODS
  Twenty healthy volunteers participated in the experiments. The present study assessed autonomic parameters such as blood pressure, heart rate, respiratory rate, and skin temperature to determine the arousal level of the autonomic nervous system. In addition, subjects were asked to estimate their mood responses such as feeling pleasant or unpleasant, uncomfortable, sensuality, relaxation, or refreshing in order to assess subjective behavioral arousal. Finally, electroencephalogram (EEG) was recorded from 31 electrodes on the scalp according to the international 10 to 20 system, and EEG power spectra were calculated by Fast Fourier Transform (FFT). Data was analyzed by comparing the effects of lavender oil on physiological and mood states with sweet almond oil. These assessments were measured before and after using paired t-test statistical procedure.
  
  
  RESULTS
  The results revealed that lavender oil caused significant decreases of blood pressure, heart rate, and skin temperature, which indicated a decrease of autonomic arousal. In terms of mood responses, the subjects in the lavender oil group categorized themselves as more active, fresher relaxed than subjects just inhaling base oil. Compared with base oil, lavender oil increased the power of theta (4-8 Hz) and alpha (8-13 Hz) brain activities. The topographic map showed obviously more scattering power in alpha range waves particularly in bilateral temporal and central area.
  
  
  CONCLUSIONS
  The findings provided evidence the relaxing effect of inhaling lavender oil.
authors.affiliation: College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Winai
authors.initials: W
authors.lastname: Sayorwan
authors.forename: Vorasith
authors.initials: V
authors.lastname: Siripornpanich
authors.forename: Teerut
authors.initials: T
authors.lastname: Piriyapunyaporn
authors.forename: Tapanee
authors.initials: T
authors.lastname: Hongratanaworakit
authors.forename: Naiphinich
authors.initials: N
authors.lastname: Kotchabhakdi
authors.forename: Nijsiri
authors.initials: N
authors.lastname: Ruangrungsi
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D001341:Autonomic Nervous System / Q000187:drug effects* / Q000502:physiology; D001921:Brain / Q000187:drug effects* / Q000502:physiology; D004644:Emotions / Q000187:drug effects*; D005260:Female; D006801:Humans; D027523:Lavandula; D008297:Male; D009822:Oils, Volatile / Q000008:administration & dosage / Q000494:pharmacology*; D010938:Plant Oils / Q000008:administration & dosage / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D009822:Oils, Volatile; D010938:Plant Oils; C045718:lavender oil