Jonas Olofsson

Jonas Olofsson, Associate Professor of Psychology, main author of the article.

– These findings may explain why it is so difficult to recognize smells. The brain reactivates the olfactory system to understand that the word is not correct, but it’s not the entire olfactory brain that is reactivated, only the regions where the smells are translated into linguistic expressions, says Jonas Olofsson, Associate Professor of Psychology at Stockholm University.

The experimental method allowed the researchers to identify an “interface” between smell and language in the brain. Two brain regions were activated in the experiment; the anterior part of the temporal lobe and the lower part of the frontal lobe. These areas are known for bringing together information from different senses.

– These areas are involved very early in the brain’s processing of smell cues. This differs from visual cues that engage many regions of the brain before being translated to language. Perhaps the olfactory brain simply is not as refined in its ability to translate sensory impressions to language, says Jonas Olofsson.

The results may be helpful in the development of smell tests for detecting dementia as the ability to recognize smells are particularly impaired in early stages of Alzheimer’s disease.

– Now that we know more about the brain regions needed to recognize smells, we might design better tests that challenges the regions that are particularly vulnerable in dementia syndromes, says Jonas Olofsson.

About the Study

The researchers constructed a psychological experiment where participants decided whether a word such as “lemon” matched with an object that was presented just before the word. Previous studies had shown that words whose meaning violates the context, for example when an image of a rose is followed by the word “lemon”, activate brain language networks. However, in this study, the object was sometimes presented visually (e.g. a picture of a rose), sometimes by its smell. This affected the brain activity evoked by the following words, indicating that the brain reactivated sensory areas to determine the meaning of the words.

The study was conducted by researchers at Stockholm University and Northwestern University in Chicago, USA. Jonas Olofssons research is funded by the Swedish Research Council and the Swedish Foundation for Humanities and Social Sciences.

Link to the Journal of Neuroscience: http://www.jneurosci.org/

For further information

Jonas Olofsson, Associate Professor of Psychology at Stockholm University, tel 070-921 03 57, email jonas.olofsson@psychology.su.se