Some studies have suggested that a damaged sense of smell can predict dementia, and others have focused on finding the causes of this. In addition, the latest research shows that people with good spatial memory can better identify smells . Information related to time and space is present in the anterior olfactory nucleus, an area of the brain that is involved in the development of Alzheimer’s disease.
On the way to unraveling this mystery that links odors and the brain, a team of scientists has found several interesting clues.
The new study, published in The Journal of Neuroscience , adds breath into this mix as well. The research, conducted by scientists at the Karolinska Institute in Stockholm, Sweden, finds that breathing through the nose, rather than the mouth, improves olfactory memory.
Breathing through the nose can help memory
The neuroscientists asked a team of male and female participants to learn 12 new smells on two separate occasions. After each “inhalation session,” they asked the participants to breathe through their nose or mouth for 1 hour.
When this time was up, the participants smelled the 12 old scents along with the other dozen new ones. Then they decided which smells were the old ones and which were the new ones. In general, when volunteers breathed through their noses, they memorized smells better than when they breathed through their mouths.
“Our study shows that we remember smells better if we breathe through our noses when memory is consolidating, the process that takes place between learning and memory retrieval. This is the first time that anyone has demonstrated this,” explains Artin Arshamian, leader of the work.
As the scientists explain, previous research has shown that olfactory receptors in the brain can pick up not only smell, but also small variations in airflow, in which different parts of the brain are activated upon inhalation and exhalation.
However, scientists currently do not know how these different breathing patterns affect human behavior.
“The idea that breathing affects our behavior is not really new,” says Arshamian. “In fact, knowledge has existed for thousands of years in areas such as meditation, but no one has succeeded in scientifically demonstrating what actually happens in the brain. Now we have tools that can reveal new clinical knowledge,” continues the expert.
Using these new tools, Arshamian and his team plan to discover the exact mechanism responsible for the effect that breathing has on olfactory memory.
“The next step is to measure what actually happens in the brain during respiration and how this relates to memory,” says the study’s lead author.
“This was previously a practical impossibility as the electrodes had to be inserted directly into the brain. We have managed to solve this problem and are now developing, together with my colleague Johan Lundström, a new means of measuring activity in the olfactory bulb. to insert electrodes “, clarifies Arshamian.
Reference: An intrinsic association between olfactory identification and spatial memory in humans. Louisa Dahmani, Raihaan M. Patel, Yiling Yang, M. Mallar Chakravarty, Lesley K. Fellows & Véronique D. Bohbot. Nature Communicationsvolume 9, Article number: 4162 (2018)
