According to the expert, the sense of smell is underestimated in contemporary culture, in which we focus mainly on vision. However, a number of studies show that smell is of great importance in many spheres of human activity.

"The sense of smell is a fascinating sense and perhaps an underestimated one. We believe that it is worth attention and we continue to discover new links between this sense and the human psyche" - emphasises Dr. Oleszkiewicz, who conducts research on human sense of smell and taste at the Institute of Psychology of the University of Wrocław.

The expert reminds that the sense of smell regulates our nutrition-related behaviour, determines whether we like something or not, because the senses of smell and taste are very closely linked. We are more creative in the presence of pleasant scents, fragrant environment affects our purchasing decisions, and for example the acrid smell of smoke alerts us to danger, which helps us survive.

In their research, Wrocław scientists are trying to find out what socially useful information people draw from the surrounding scents and how they function in an environment, in which different kinds of fragrances are present.

In the studies of smell, they use the standardized Sniffin `Sticks test invented at the Smell and Taste Center in Dresden, with which the Wrocław Institute closely cooperates. The test, which consists of fragrance sticks, is mainly used to diagnose the function of smell, check whether a person has a good or weak sense of smell.

But scientists at the institute also conduct research on the smell of the human body. In these studies, scientists use human sweat collected from volunteers. In addition, "sweat donors" complete a personality questionnaire before entering the study. The questionnaire is are also completed by two close relatives. In this way, the criterion of accuracy is obtained.

"Knowing the personality of a given person, we could determine how accurately these traits were deduced from the sweat by the participants of the study, whose task was to sniff these samples" - explains Dr. Oleszkiewicz. The results of the study show that the scent of the human body allows to deduce, whether someone is neurotic - secretive, nervous, or just the opposite - the person is an extrovert who likes to spend time with others, an open and communicative person.

Other interesting conclusions came from research conducted on couples. It turned out that over the years, people living together become similar in terms of their taste and smell preferences. "This means that the longer people are together, the longer they eat meals together, spend time together in the same space, the more their preferences concerning smells and flavours become similar" - the researcher says.

In another study, the researchers checked the sense of smell of the blind. "We wanted to verify the common belief that people who do not see should have improved sense of smell. But our research has not confirmed this. The blind people and people with similar demographic characteristics, who have fully functional sight, performed olfactory tasks in the same way" - says Dr. Oleszkiewicz.

In the next project, researchers want to compare blind and deaf people in terms of olfactory skills, taste preferences, and tactile sensitivity.

Scientists at the Institute of Psychology of the University of Wrocław also conduct innovative research on olfactory memory, i.e. memory associated with or induced by scents.

According to Agnieszka Sabiniewicz from the Institute of Psychology of the University of Wrocław, the example of returning home after a long journey is a good illustration of what the olfactory memory is. When we open the door, all scents associated with this place that we know well come to us, as do all the memories and usually positive emotions that are associated with those scents.

"So far, research has mainly focused on the properties of fragrances as factors that induce recalling memories. It turns out that these memories have very specific and interesting properties - they are expressive, strongly emotional and usually much older than the memories caused by other stimuli, for example visual or auditory ones" - explains the PhD student.

Wrocław scientists have developed an olfactory memory test, which consists of 32 fragrance sticks. The large number of fragrances - in their opinion - allows to precisely differentiate the level of olfactory memory of the subjects. The test allows to check if the olfactory memory is connected with cognitive abilities.

"In this case, we have selected several types of memory: working and spatial memory, for which theoretical premises show that such links can actually occur. We also want to check if certain personality traits are also connected with the level of olfactory memory" - adds Sabiniewicz.

Researchers admit that olfactory studies are also important in psychiatry, because problems with smell can be an early marker of neurodegenerative diseases.

"Problems with smell begin about 10 years before the onset of Parkinson`s and Alzheimer`s disease. Recent studies show that in the case of Parkinson`s disease there is a very specific pattern of loss of olfactory function, because patients are still able to smell, but they are not necessarily able to accurately locate sources of smells. They also perceive certain smells as less burning or tickling in the nose. This function, responsible for perceiving certain odours as cold, burning or tickling, disappears quite early in the case of Parkinson`s disease" - says Dr. Anna Oleszkiewicz.

PAP - Science in Poland, Kamil Szubański

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