Researchers have shown that lavender and rosemary administered through aromatherapy positively affect psychological and physiological functioning. In a study conducted by the Touch Research Institute at the University of Miami Medical School, first published in the International Journal of Neuroscience, researchers assessed the effect of lavender and rosemary on alertness, mood and the brain's electrical activity, and on subjects' ability to perform math computations.
In the study, 40 adult faculty and staff members of the University of Miami Medical School were randomly placed into one of two groups, and were asked to inhale the scent of either lavender or rosemary essential oil for three minutes. Those in the lavender group were expected to show an increase in alpha and beta band activity, suggesting relaxation. Those in the rosemary group were expected to have a decrease in alpha and beta band activity, suggesting greater alertness.
Results showed that study expectations were correct: Participants in the lavender group experienced an increase in beta band activity, suggesting drowsiness; an improvement in mood; a feeling of greater relaxation; and better performance on math computations.The rosemary group showed a decrease in alpha and beta power, suggesting alertness and lower levels of anxiety; and were faster but not more accurate at performing math computations.