Alexithymia modulates the attitudes towards odors but not the olfactory abilities or the affective reactions to odors

by Cinzia Cecchetto, Elisa Dal Bò, Marilena Aiello, Florian Ph.S Fischmeister, Claudio Gentili, Sofia Adelaide Osimo

A new study, published in PLOS ONE journal, investigated the different aspects of olfactory perception in individuals with alexithymia. The study is the result of a collaboration of the University of Padua with the University of Milano-Bicocca, the University of Bologna, and the Medical University of Vienna.

Alexithymia is a psychological construct characterized by impaired emotional processing. Although emotions and smell are closely connected to each other, only a few studies have investigated olfaction in individuals with alexithymia, reporting alterations in olfactory perception. However, these studies do not allow for comprehensive conclusions.

Do alexithymic individuals have reduced olfactory abilities or do they just have altered emotional reactions to odors compared to non-alexithymic individuals? Are alexithymic individuals less aware of environmental odors than non-alexithymic individuals?

In the present study, we attempted to answer these questions through three experiments. The first experiment tested basic olfactory skills (identification, discrimination and detection of odors). The second experiment investigated the subjective perception of the affective qualities of odors, meaning intensity, pleasantness, and familiarity. The third experiment analyzed, through an online survey, the allocated attention and awareness of odors presented in the environment.

We observed that alexithymic individuals have the same basic olfactory abilities and showed no differences in the affective evaluation of odors compared to non-alexithymic individuals. However, alexithymic individuals reported reduced awareness and reduced interest towards olfactory stimuli. One possible explanation for this result may be that individuals with alexithymia exhibit reduced attentional allocation for emotional stimuli and the tendency to externally oriented thinking style rather than focusing their attention on emotions. Olfactory stimuli are intrinsically related to emotions: they can elicit strong emotional reactions and emotional biographical memories. Individuals with alexithymia may allocate reduced attention to olfactory stimuli to avoid the related emotional contents.

These results help us to have a better understanding of how alexithymia impacts the perception of hedonic stimuli coming from different sensory modalities and also open new possibilities towards possible treatments. Indeed, they imply that treatment goals for alexithymia should include the enhancement of the conscious perception of odors, supporting the use of mindfulness-based protocols in the treatment of alexithymia.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0278496