[Responses of electroencephalogram to different odors]

Effect of Volatile Organic Chemicals in Chrysanthemum indicum Linné on Blood Pressure and Electroencephalogram

This study identified the volatile organic compounds in the essential oils that are extracted from Chrysanthemum indicum Linné (C. indicum Linné) and investigated the effects of the inhalation of these compounds. We detected a total of 41 volatile organic compounds, including 32 hydrocarbons, four acids, three alcohols, two ketones, and one aldehyde. In a sniffing test, seven types of volatile organic compounds were identified. Furthermore, the volatile organic compounds in C. indicum Linné that were identified were found to be derived from 1,8-cineole and camphor. After inhalation of the essential oils, the subjects’ systolic blood pressure and heart rate decreased. This indicates that inhalation of the essential oils extracted from C. indicum Linné provides mental and physical relaxation. We examined the changes in electroencephalogram findings that are observed after C. indicum Linné essential oil inhalation. An increase in theta and alpha waves, which usually appear during relaxation, as well as a decrease in beta and gamma waves, which appear during brain activity such as excessive attention, were noted. These results indicate that C. indicum Linné essential oil inhalation helps to reduce blood pressure and may provide mental and physical relaxation.

Expectancies, not aroma, explain impact of lavender aromatherapy on psychophysiological indices of relaxation in young healthy women

OBJECTIVES

In aromatherapy, lavender aroma is reputed to assist with relaxation. However, while there is much anecdotal evidence to that effect, the empirical literature is very inconsistent. Failure to employ adequate placebos, proper blinding, objective measures, or screening of prior beliefs about aromatherapy means that many previous findings could have been influenced by expectancy biases. The present study sought to establish whether lavender aroma and/or expectancies affect post-stress relaxation.

DESIGN

A double-blind, 3 (aroma) x 3 (instruction) x 10 (time in minutes) mixed-factorial placebo-controlled trial.

METHOD

In a laboratory, 96 healthy undergraduate women were exposed to lavender, placebo, or no aroma during physiologically assessed relaxation after an arousing cognitive task. Where an aroma was presented, an instructional priming procedure was used to manipulate participants' expectancies about the aroma's likely impact on their ability to relax.

RESULTS

Results showed no effect of aroma on galvanic skin response during relaxation. However, the nature of instructional prime was associated with relaxation patterns: when expecting the aroma to inhibit them, participants relaxed more; when expecting facilitation, participants relaxed less. The effect was not seen with regard to self-reported relaxation (as represented by changes in state anxiety) and was independent of ratings of attitudes towards aromatherapy.

CONCLUSIONS

The findings imply that the previous associations of lavender aroma with assisted relaxation may have been influenced by expectancy biases, and that the relevant expectancies are easily manipulable.