It is, according to researchers from the CNRS (French National Centre for Scientific Research) and Inserm (French National Institute of Health and Medical Research) team devoted to the study of the olfactory memory [1], another example of the human brain’s amazing plasticity [2]. These results, obtained through anatomical MRI performed on professional perfumers, students in perfumery and control subjects, also show that training can reverse the age-related decline in the volume of grey matter in olfactory areas, which is observed in the general population.
The same team of researchers has shown in earlier studies that training enables perfumers develop the capacity to mentally imagine smells they can virtually "feel" in their nose while it is not physically present. Scientists have also observed that perfume experts enjoy a more efficient, rapid and specific neuronal communication in their brain’s olfactory areas.
Researchers thus wondered whether the intensive training of perfumers was also reflected by an increase in the volume of grey matter in the brain areas related to olfaction. To answer this question, they submitted 14 renowned expert perfumers, including Jean-Claude Ellena and Daniel André, to an MRI. The same test was conducted on 13 students from the Versailles-headquartered French school of perfumery (ISIPCA - Institut Supérieur International du Parfum, de la Cosmétique et de l’Aromatique Alimentaire), and 21 subjects with no particular expertise in perfumery.
© JP Royet
Anatomical images of the brains of young and professional perfumers as well as those of age-matched control subjects were produced using an fMRI scanner.
The MRIs showed that perfumers have a greater volume of grey matter in the primary olfactory cortex and the orbitofrontal region, next to the olfactory sulcus, than control volunteers. Furthermore, the volume of grey matter appears to be directly correlated with a perfumer’s experience. The more trained they are, the bigger the volume of olfactory areas is.
However, the researchers found the volume of these brain areas to significantly decrease with age in control subjects, and that the process is general and continuous when no training is performed. Thus indicates that the brain changes observed among perfume experts are the result of training and are not innate characteristics.
© JP Royet
Training and professional perfumers have a greater volume of grey matter in their primary olfactory and medial orbital cortex (yellow) than control subjects. The more experienced are professional perfumers, the bigger the volume of grey matter in the high median orbital cortex (green) is. Conversely, the older control subjects are, the lighter this volume is (blue).
"These results remind us similar structural changes observed in other expert categories such as musicians, athletes, multilingual individuals, mathematicians, or taxi drivers. All these specialists reorganize and over-develop specific brain areas according to their expertise. The amazing brain’s ability to adapt to environmental demands and to reorganize with experience seems to be limitless," says the CNRS in a statement.
