3 new sensory discoveries in cosmetic science from IFSCC

Transmitting positive emotions through body odour ​

Aline Robert-Hazotte from Shiseido Group’s European Innovation Centre presented “Deep dive in emotional communication in humans: study of the transmission of positive emotions through body odour.”​

The briefing outlined how body odour is a communication tool that transmits information between humans.

Although studies had already found that the contagion of negative emotion was possible through body odour, the team had set out to investigate whether positive emotional communication was also possible through this medium.

For the study, participants were asked to wear a t-shirt with a gauze pad to collect their body odour. One group watched videos that showed happiness-inducing images, such as laughing babies, while the other watched more neutral images. The participants were all also asked specific questions that were designed to induce certain emotions.

The t shirts they had worn were then given to other participants who had to answer verbal questions about how they felt and have they physiological responses and emotional reactions measured.

The study also measured their behavioural responses by asking them to undertake various creativity tasks after they had smelled the odour on the t-shirt.

The results found that the participants who received the t shirts with ‘positive emotion’ body odour had a decreased heart rate in the physical tests. While for the verbal questions, the majority described the odour as ‘pleasant’ and ‘relaxing’. This group also performed much better in the creativity tasks in comparison to those who had received a t-shirt with the neutral body odour.

The team also carried out a study to find out if fragrance modulates this contagion of positive emotions by repeating the same study but by adding fragrance to the t shirt for the experiment. In this, they found that fragrance didn’t interfere with the contagion of positive emotion through body odour.

Overall, Shiseido Group’s conclusions made from the study were:

• Confirmation that positive emotions can be transmitted though body odour.
• Fragrance does not interfere with natural human communication and can therefore preserve, or even promote, the transmission of happiness.
• It offers new perspectives to develop fragranced products that are capable of enhancing happiness and social communication between individuals.
• It opens interesting perspectives to develop new cosmetics that enhance the holistic approach of wellbeing. 

Use of the Stroop Effect when marketing fragrance  ​

For the study: “Olfactory Stroop Effect: Neural Correlates of Scent Cognitive Interference​”, Hugo Alexandre Ferreira from the University of Lisbon set out to discover whether The Stroop Effect happens with scent.   

The Stroop Effect is the delay in reaction time between congruent and incongruent stimuli. For example if the word ‘yellow’ is written in green ink it instantly confuses the mind and someone might taken longer than usual to be able to tell you what colour the word is or to say what the word says.  

The team presented a test on six participants with six congruent and six incongruent scent word pairs randomly presented, for example for the incongruent ones they gave participants a coffee scent and showed the word ‘lemon’ then they asked them to name the scent and recorded the naming and the response time.

The study also recorded the participants brainwaves using an EEG to monitor which parts of the brain were activated and which brainwaves were used. It also monitored their heart rate using an ECG scan to record their stress levels.

As expected, the congruent stimuli resulted in more correct answers than the incongruent stimuli and on average.

However, what was unexpected was that participants took 8.6 seconds longer to describe the congruent stimuli than the incongruent stimuli. They answered the incongruent stimulant questions faster, but were often wrong.

The scents of smoke and coffee caused the most confusion, while the fragrances of lemon and grass were the most consistent and more people were able to answer correctly when these scents were used in the study.

For correct answers the team spotted were notable similarities in delta and gamma waves.

While for incorrect answers, the brain waves showed different patterns.

When the answer was incongruent, the prefrontal cortex was activated: the region of the brain associated to working memory and internally driven decision making, which is related to impulse control. Along with the dorsolateral prefrontal cortex which related to decision making, inhibition and working memory. 

From the study, Ferreira's overall conclusions were:

• The use of incongruent scent words resulted in a higher error naming, especially for coffee and lavender.
• But overall, faster correct responses were observed for incongruent stimuli, which is the opposite of the traditional Stroop Effect.
• Different neurophysiological responses are observed for the different scents. Smoke and coffee both showed a boost in heart rate too.
• When marketing a new scent product, brands can use words on the pack that correlate with the feelings they want to elicit. For example: if they want to elicit a response of comfort then it is best to use a congruent word on pack. If they want to elicit surprise then it's best to use one that’s a total opposite to elicit surprise/curiosity.
• Ferreira said the test could also be used to assess health and ageing for different populations, for example loss of smell due to age-related illnesses.

Sleep-enhancing scent​

Celine Carrasco Douroux Applied Research Director for Symrise explained that as part of the company’s Neuroscience program after the COVID-19 pandemic, it investigated lack of sleep and stress-induced insomnia.

In her presentation “Objectification of the sleep regulating power of a perfume after repeated use for 28 days to improve long-term effectiveness on sleep quality,”​ Carrasco Douroux noted the symbiotic relationship between stress and sleep, the negative cycle that lack of sleep triggers and how it causes various health issues.

She explained that the company’s recent research shows that scent can improve sleep quality “in terms of the complex relationship between stress and sleep.”​

When someone breathes in a scent, the molecules travel up the olfactory system in the nose and go straight to the limbic system of the brain, which then communicates with the central nervous system, which controls heart rate, breathing, sweating and facial expressions. According to Carrasco Douroux, this means that the scents we inhale influence our emotions and moods and affect instinctive bodily functions.

Symrise’s neuroscience studies show that scents have a direct effect on emotions, mood, stress, insomnia and cognitive function.

Before the study, Symrise trialled many ingredients to qualify the emotions they triggered in participants.

It tested various accords in the US and France: two relaxing, one wellbeing and one mixture of relaxing and wellbeing and measured the strength of congruence of fragrance and emotion and then tested the response time.

It found that its White Relaxing scent was the most relaxing, so this was chosen as a pillow mist for the main study, which was conducted on Caucasian volunteers, male and female from 20-50 years old with non-pathological tiredness.

For the first week there was no pillow mist, then for the next three weeks they had to apply the White Relaxing pillow mist every night.  

The participants had to do a self-reported questionnaire based on the Pichot Fatigue Scale and the Epworth Sleepiness Scale state of fatigue through the day. They were also tested using a non-invasive method that records movement during the night when they were sleeping.

At the end of the study, after using the pillow mist, the subjects showed less tiredness on Pichot scale and lower on Epworth sleepiness effect.

The study found that they fell asleep faster, slept for longer, the sleep efficiency was higher and they woke up less in the night.

The overall conclusions were:  

• Daily use of the tested produced significant results from both a subjective and objective point of view.
• Psychometric. From a subjective perspective, long-term use of the product significantly reduced sleepiness and fatigue and increased perceived sleep quality.
• ‘Altmetric’: From an objective point of view, long-term use of the product significantly increased sleep efficiency.
• In conclusion, long-term use of the product tested with the support of neuroscience did not depend on a single sleep component but acted as a global effect and has been shown to improve sleep quality.