space.template.Research+review

=Lavender enhances concentration during fatigue =  RESEARCH REVIEW by Ilona Lantos

 Reviewed: Reiko Sakamoto, Kazuya Minoura, Akira Usui, Yoshikazu Ishizuka and Shigenobu Kanba: Effectiveness of Aroma on Work Efficiency: Lavender Aroma during Recesses Prevents Deterioration of Work Performance, Chemical Senses, Apr 2001; 26: 239 - 245.

 The online version of this article was downloaded by ilona lantos on July 4, 2010 from: []


 * Keywords**: lavender, jasmine, concentration

Previous studies examined essential oils for their sedative (lavender) and stimulatory (jasmine, peppermint) qualities and their effects on work performance. In one study electroencephalography (EEG) showed increased activity in the frontal lobe during excited states (jasmine) and decreased activity during sedated states. In previous studies lavender decreased calculation rates (Ludvigson and Rottman, 1989) or work performance (Moss et al, 2003), but conversely in another study lavender increased accuracy in arithmetical calculations compared to the jasmine and control groups. (Degel and Koster, 1999) While former studies indicated that lavender reduces work efficiency, this latter indicates that during stressful periods lavender has the opposite effect that is increases work performance. The current study further investigated the effect of lavender which was introduced during recess time between work sessions in this study as opposed to former studies when lavender was introduced during work performance.
 * Introduction:**

In this study about 36 healthy male university students participated, average age 24. Participants were randomly divided into two experimental groups and one control group.
 * 1. Subjects,** **size** **and method of selection**

Five experiments were conducted between 0930 and 1700 for 1 day, each of them was a 60 minute-long computer task requiring concentration. Each experimental group was exposed to the selected aroma during a 30 min recess between each session.
 * 2. Length**

Participants were asked to have sufficient sleep and avoid alcohol, cigarettes, medications, cosmetics or caffeinated drinks starting 2 days before the experiment to prevent fatigue. Each control group was exposed to the selected aromas (lavender and jasmine) while the control group was not exposed to any aroma during recesses. All participants worked in the same area but during recess each group used its group room. During the work session participants performed some monotonous work on the computer using a performance efficiency assessment program which provided two indicators tracking errors and response time.
 * 3. Methodology**

The indicator of concentration displayed a U shaped curve in each work session gradually declining from start then climbing up what is called "The Last Spurt Effect" (Kuraishi at al, 1957). Significant decrease of concentration occurred in the control group during the work session between 1430 and 1530, which is known as the time when work efficiency usually decline (Monk et al, 1996). Significant inter-group differences occurred during work session between 1430 and 1530. Concentration in the lavender group was the highest compared to both the control group and the Jasmin group.
 * 4. The results**

The authors of this study suggest that though lavender generally is considered sedative, when mental fatigue is present, smelling lavender can prevent deterioration of performance. They also acknowledged some limitations, such as the extent aroma preferences might have influenced the results or the short length of the study.
 * 5. The authors/researchers conclusions**

Interesting to consider that the same aroma can have opposite effect on the mind depending on the given emotional and mental state. It would be interesting to know the botanical name of lavender oil used in this study. Lavandin (Lavandula intermedia) ﻿﻿is high in camphor and is a stimulant as opposed to true lavender (Lavandula angustifolia), which is highh in ester linalyl acetate, which gives it its smoothing quality.
 * 6. Personal thoughts/analysis of the results**

Ludvigson, H.W. and Rottman, T.R. (1989) Effects of ambient odors of lavender and cloves on cognition, memory, affect and mood. Chem. Senses, 14, 525–536.
 * References:**

Degel, J. and Koster, E.P. (1999) Odors: implicit memory and performance effects. Chem. Senses, 24, 317–325.

Kuraishi, S., Kato, M. and Tsujioka, B. (1957) Development of ‘‘Uchida–Kraepelin psychodiagnostic test’’ in Japan. Psychologia, 1, 104–109.

Monk, T.H., Buyesse, D.J., Reynolds, C.F. and Kupfer, D.J. (1996) Circa- dian determinants of the mid-afternoon dip in performance. Chronobiol. Int., 13, 123–133.

Moss M, Cook J, Wesnes K, Duckett P. (2003) Aromas of rosemary and lavender essential oils differentially affect cognition and mood in healthy adults. International Journal of Neuroscience 113(1):15-38.