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Olfactory research

Click on the external links below for the latest in olfactory research.

• Department of Experimental Psychology University of Oxford
• School of Biosciences University of Cardiff
• The Sense of Smell Institute New York

Research Summaries

The sense of smell is the most powerful human sense as it has a direct trigger to the brain invoking instant reaction. Consequently there has been a large amount of research into the effects of smell on human behaviour. The following are a selection of findings, funded by The Sense of Smell Institute, Inc. and relevant to the Scent Technologies Ltd. market sectors. Click on the title to see the associated research summary.

• Olfactory stimulation and sustained attention - Joel S, Warm, Ph.D., William Dember, Ph.D. and Raja Parasuraman, Ph.D.
• Fragrance administration and relaxation training for treatment of anxiety during magnetic resonance imaging in cancer diagnosis - William Redd, Ph.D. and Sharon Manne, Ph.D.
• The emotional distinctiveness of odour-evoked memories - Rachel S. Herz, Ph.D.
• Consumer panel study on the effect of peppermint and lavender fragrances on proof-reading efficiency - Mary Kliauga, Kathy Hubert and Terry Cenci
• The effects of odours on objective and subjective measures of physical performance - Bryan Raudenbush, Ph.D.
• Congruent and incongruent odours: their effect on behaviour in stores and museums - Susan C. Knasko, Ph.D.

Olfactory stimulation and sustained attention

Joel S, Warm, Ph.D., William Dember, Ph.D. and Raja Parasuraman, Ph.D.
Do certain fragrances have the potential of improving one's performance accuracy during vigilance tasks? This paper is a summarisation of four experiments, all of which addressed this question. The first two studies measured both performance accuracy and stress. The subjects' task was to detect the occurrence of visual signals on a video monitor during the delivery of peppermint, or unscented air. The last two experiments focused on the role attentiveness may take when measuring performance accuracy. Overall, results showed that both fragrances enhanced the performance accuracy of subjects during vigilance tasks. Level of attentiveness improved with the administration of peppermint-scented air, but only for those subjects characterised as inattentive prior to the experiment.

Fragrance administration and relaxation training for treatment of anxiety during magnetic resonance imaging in cancer diagnosis

William Redd, Ph.D. and Sharon Manne, Ph.D.
Researchers at Memorial Sloane-Kettering Cancer Centre performed an experiment to investigate the possibility of using fragrance as a way to alleviate the anxiety felt by patients undergoing magnetic resonance imaging. The study consisted of 57 subjects (26 men, 31 women) who were undergoing a diagnostic work-up for cancer. A plastic tube was placed in the patients' nostrils during their MRI exam, which delivered bursts of air for the control group and the odour of vanilla-like scent for the experimental group. Findings showed that patients who received heliotropin reported 63% less anxiety than patients who received air alone. Interesting to note is that the positive effects of the aroma were found only for those individuals who rated it as a pleasant odour. Only a 5% reduction was found for subjects in the control group.

The emotional distinctiveness of odour-evoked memories

Rachel S. Herz, Ph.D.
The objective in this experiment was to determine how well odour measures up to the other senses in providing retrieval cue to memory. In Experiments 1 and 2, comparisons were made between olfactory, tactile and visual stimuli (smell, feel and sight of an apple) as memory cues. In Experiment 3, odour cues were compared with verbal cues. Odour cues were shown to be as equally effective as both visual and tactile cues in prompting memory accuracy. However, odour cues produced memories having a greater intensity of emotions. Experiment 3 showed that a memory cue would be a superior reminder if it is experienced in the same modality both at encoding and retrieval time.

Consumer panel study on the effect of peppermint and lavender fragrances on proof-reading efficiency

Mary Kliauga, Kathy Hubert and Terry Cenci
A two-phase study was done to see whether the smell of peppermint and lavender had an effect on a person's efficiency at proofreading. Subjects completed the proofreading tasks under three separate room conditions: peppermint scented, lavender scented, and no scent. Scores improved the most under lavender fragrance and to a much lesser degree under peppermint. Results of the second phase were not as consistent. However, when results were pooled together, fragrances were shown to improve efficiency. Although the sample of men was significantly smaller, their scores improved more with peppermint fragrance whereas the scores of the women in the sample were raised by lavender scents.

The effects of odours on objective and subjective measures of physical performance

Bryan Raudenbush, Ph.D.
Previous research has indicated that the presentation of odours can have both positive and negative effects on the performance of cognitively-based tasks. The presentation study was designed to extend past research by assessing the effects of odour administration on objective and subjective measures of physical performance. Forty athletes performed a modified 15-minute treadmill exercise stress test under each of four conditions. These conditions consisted of the presentation of one of three odorants (peppermint, jasmine or dimethyl sulphide) or a non-odoured control condition via a nasal cannula. During testing, objective physiological variables such as pulse, blood pressure, oxygen saturation and MAP were measured. In addition, more subjective measures of workload, such as the NASA-TLX (NASA-Task Load Index) and the POMS (Profile of Mood States) were administered. No significant effects were found for the objective physiological measures for any odorant. However, peppermint odour significantly reduced perceived physical workload, temporal workload, effort and frustration. Self-evaluated performance was also greater in the peppermint condition, and participants rated their level of vigour higher and their level of fatigue lower. Few to no effects were found for the jasmine or dimethyl sulphide conditions. The implications are particularly salient in regards to enhancing athletic performance using a non-pharmacological aid and as an adjunct to athletic training and physical therapy.

Congruent and incongruent odours: their effect on behaviour in stores and museums

Susan C. Knasko, Ph.D.
Three studies were conducted to determine whether
a) Pleasant odours increase a person's lingering time and
b) Congruency of the odour to the environment has an affect on lingering time.
The first two studies were implemented in a laboratory setting. Both indicated that pleasant odours do in fact increase lingering time. Congruency however, offered little effect. The last experiment took place at a museum exhibit. Results of this study indicated that both pleasantness of the odour as well as odour congruency influenced approach behaviour.