Some people are sceptical when it comes to the notion of aromatherapy or using scents and odours as a means of manipulating people’s mood, dismissing the idea as simply the placebo effect taking place. However, recent researches have shown there are actually scientific explanations that back up and prove the mood affecting effect of different scents.
A group of researchers from International Flavors and Fragrances, Inc. has developed their interest in the research concerning scents and their links to mood manipulation. In this study, the researchers devised a method they named ‘Mood Mapping’, which has been noted to “reliably measure the mood association of aromas” by voting on-the-spot how certain scents made them feel.
During Mood Mapping, participants were given citrus and vanilla scents and were tasked to identify and vote what feeling was elicited upon the inhalation of the scent. The study showed that most participants voted that citrus made them feel ‘happy and stimulated or energised’, while vanilla was linked to being ‘happy but relaxed’.
However, scientific research has shown that only scents extracted from the real natural source, like real vanilla beans and real citrus fruits, have been shown to elicit the effect, synthesised scents do not elicit the same response.
A research presented by Nicole Hovis and Theresa White of Le Moyne College in Syracuse, New York shows that there is a link between first impressions and scents. In this study, participants were given vials of citrus and onion scents and were presented with a gender-neutral silhouette which they were tasked to formulate an impression of.
The results of the study showed that participants given vials containing an onion scent were more inclined to perceive the silhouette as manly, while participants given vials containing citrus scents were noted to perceive the silhouette as more feminine, pleasant and clean.
A study headed by Jeanette Haviland-Jones illustrated the effects on behaviour of non-detectable floral scents. In the study, researchers perfumed a room with classic floral scents and had a batch of participants write an essay about three life events: one from the past, one from the present, and one that could probably happen in the future.
Another batch was tasked to write an essay in a baby powder scented room, and another in a non-scented room. The essays were coded based on how many positive and negative words were used in the writing. The results showed that essays written inside the floral scented room contained 300% more positive words than those written in the other rooms.
The second part of the study required the participants to direct a mime to re-enact a memory from their childhood. About 74% of participants in the floral scented room actually touched the mime when they were directing him, while only 15% of the participants from the other rooms did so.
These results were linked to the relation of floral scents and its effect of promoting positive thoughts, social interaction, and socially inclined behaviours.
There is actually a science in the connection of mood improvement and olfactory stimulation. When lemon oil (citrus) is inhaled, some of the lemon oil scent molecules dissolve in the mucus lining of the olfactory epithelium, which is located on the roof of the nasal cavity.
Olfactory receptors are stimulated by the molecules which are then received by olfactory sensory neurons. The neurons then carry the signals to the olfactory bulb where the stimulus of the lemon scent is registered. Cells called mitral cells then carry the output signals from there to the olfactory cortex in the brain. This allows you to process and recognise the familiar tangy scent of lemon.
The connection lies in the process where in the mitral cells carry the signals to some areas in the Limbic system. The human limbic system structures are involved in many of our emotions and motivations.
Part of the limbic system is the amygdala, which is primarily responsible for hormonal secretions, emotional responses and memory. Along with the amygdala is the hippocampus – which is a tiny nub responsible for the storage of long-term memories and retrieving of memories when necessary. This explains why certain scents trigger memories. “When your mood is better, you find memories in your mind that match the mood you’re in” said study researcher Patricia Wilson of La Salle University in Philadelphia.