The neglected sense

Research into the sense of smell is a fascinating area which frequently delivers surprising results. It would appear that we subconsciously perceive signatures which tell us more about other people than we think.

Tears of sad women

A team of Israeli researchers have proven, for example, that tears shed by women watching a sad film contain a messenger substance which curbs men’s sexual arousal. Another experiment demonstrated that people check the smell of someone they have just shaken hands with by subconsciously repeatedly moving their hand to their nose afterwards. It has been known for a while that the sense of smell has an important role to play in choosing a partner as it – subconsciously – gives us information about the other’s immune system.

‘Processing smells is a highly emotional system which influences our social interactions,’ says Prof. Dr. Jessica Freiherr. She is conducting research at the Department of Psychiatry and Psychotherapy at FAU and the Fraunhofer Institute for Process Engineering and Packaging (IVV) to investigate which information is transferred via smell and taste and how this is processed in the brain.

Active areas within the brain are detected and assessed using MRI images and the emotional state of the test persons assessed on the basis of heartbeat, breathing or skin conductance.

The search for a chemical formula

The FAU project ‘Human body odours: exploring chemical signatures’ funded within the framework of the Emerging Fields Initiative (EFI) hopes to decode which molecules are responsible for the information we receive via smell. As part of the project, the olfactory properties of the sweat of healthy test persons in various emotional states such as fear, sadness or anger is analysed. A well-trained team sniffs the samples and tries to categorise the odours. ‘An important aim of our work is to develop methods able to characterise the wide range of different odorants and link this to demographic, microbiological and sensory data,’ explains the project manager Dr. Helene Loos.

In a second step, the researchers analyse the samples using a gas chromatograph and a mass spectrometer in order to uncover the secret of biochemical mechanisms of information transfer. Typical odorants such as acids, thiols and steroids can be identified in sweat, but until now we have been unable to identify which chemical compounds transport the information about emotions and other characteristics. ‘The identified odorants are not necessarily the substances which influence our behaviour,’ says Helene Loos.

It is not only neuroscientists and behavioural researchers who are interested in how smell is transferred and received – it is also a major concern for the cosmetic industry, who are keen, for example, to develop perfumes which neutralise or mask the smell of stress.

FAU research magazine friedrich

This article first appeared in our research magazine friedrich. You can order the print issue (only available in German) free of charge at presse@fau.de.