title: Aroma Effects on Physiologic and Cognitive Function Following Acute Stress: A Mechanism Investigation.
abstract: OBJECTIVE
  Aromas may improve physiologic and cognitive function after stress, but associated mechanisms remain unknown. This study evaluated the effects of lavender aroma, which is commonly used for stress reduction, on physiologic and cognitive functions. The contribution of pharmacologic, hedonic, and expectancy-related mechanisms of the aromatherapy effects was evaluated.
  
  
  METHODS
  Ninety-two healthy adults (mean age, 58.0 years; 79.3% women) were randomly assigned to three aroma groups (lavender, perceptible placebo [coconut], and nonperceptible placebo [water] and to two prime subgroups (primed, with a suggestion of inhaling a powerful stress-reducing aroma, or no prime). Participants' performance on a battery of cognitive tests, physiologic responses, and subjective stress were evaluated at baseline and after exposure to a stress battery during which aromatherapy was present. Participants also rated the intensity and pleasantness of their assigned aroma.
  
  
  RESULTS
  Pharmacologic effects of lavender but not placebo aromas significantly benefited post-stress performance on the working memory task (F(2, 86) = 5.41; p = 0.006). Increased expectancy due to positive prime, regardless of aroma type, facilitated post-stress performance on the processing speed task (F(1, 87) = 8.31; p = 0.005). Aroma hedonics (pleasantness and intensity) played a role in the beneficial lavender effect on working memory and physiologic function.
  
  
  CONCLUSIONS
  The observable aroma effects were produced by a combination of mechanisms involving aroma-specific pharmacologic properties, aroma hedonic properties, and participant expectations. In the future, each of these mechanisms could be manipulated to produce optimal functioning.
authors.affiliation: 1 Department of Neurology, Oregon Health & Science University , Portland, OR.
authors.forename: Irina
authors.initials: I
authors.lastname: Chamine
authors.affiliation: 1 Department of Neurology, Oregon Health & Science University , Portland, OR.|2 Departments of Behavioral Neuroscience and Biomedical Engineering, Oregon Health & Science University , Portland, OR.
authors.forename: Barry S
authors.initials: BS
authors.lastname: Oken
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019341:Aromatherapy / Q000379:methods* / Q000523:psychology*; D003059:Cocos; D003071:Cognition / Q000187:drug effects*; D005260:Female; D006801:Humans; D027523:Lavandula; D008297:Male; D008875:Middle Aged; D013315:Stress, Psychological / Q000628:therapy*