The following study notes a significant difference in response to different aromas - here, peppermint and ylang ylang aromas were tested, and the participant's level of awareness and calmness. Peppermint significantly heightened alertness and response time, where ylang ylang brought about calmness and slowed response time. And our big question: why don't studies like this get any press, where the recent one performed in the US showing no change in some saliva chemical markers was all over the media? With the headline that aromatherapy doesn't work? It's one thing to say different aromas do not affect saliva chemical composition...but this is the only reasonable conclusion the study could really come to. Delving into the research reveals all sorts of studies with results similar to the following:

Study: Modulation of cognitive performance and mood by aromas of peppermint and ylang-ylang.

Moss M, Hewitt S, Moss L, Wesnes K.Human Cognitive Neuroscience Unit, Division of Psychology, University of Northumbria, Newcastle upon Tyne, United Kingdom.

This study provides further evidence for the impact of the aromas of plant essential oils on aspects of cognition and mood in healthy participants. One hundred and forty-four volunteers were randomly assigned to conditions of ylang-ylang aroma, peppermint aroma, or no aroma control. Cognitive performance was assessed using the Cognitive Drug Research computerized assessment battery, with mood scales completed before and after cognitive testing. The analysis of the data revealed significant differences between conditions on a number of the factors underpinning the tests that constitute the battery. Peppermint was found to enhance memory whereas ylang-ylang impaired it, and lengthened processing speed. In terms of subjective mood peppermint increased alertness and ylang-ylang decreased it, but significantly increased calmness.

These results provide support for the contention that the aromas of essential oils can produce significant and idiosyncratic effects on both subjective and objective assessments of aspects of human behavior. They are discussed with reference to possible pharmacological and psychological modes of influence.