Effects of ambient odors of lavender and cloves on cognition, memory, affect and mood

The effects of the odors of lavender and cloves on three cognitive skills—memory, affective reaction to the experiment and mood—of college students are studied in two sessions, separated by 1 week. Essential oils of lavender or cloves were diffused throughout the laboratory, or no odor was presented. In the second session, approximately the same number of subjects from each odor condition of the first session influenced arithmetic reasoning in the first session (3 × 3 factorial design). Lavender adversely influenced arithmetic reasoning in the first session. At the same time, subjects' affective reactions to the experiment were more favorable with lavender present, though cloves decreased willingness-to-return. In the second session, effects on cognitive functioning were not evident, and effects on affect were complex: relative to no-odor controls, groups that had odor in at least one session expressed negative affect and unwillingness-to-return. Discussion concerned implications for the claim that lavender is physiologically relaxing, the surprising absence of an effect of an effect of odor change on memory, and possible interactions of odor and personality factors.