Breathing through nose linked to better memory

Swedish researchers have reported that the way our memories are consolidated depends on the way we breathe. A new of its kind study published in the The Journal of Neurosciences suggests that in order to learn a set of smell, breathing through the nose rather than the mouth helps to remember them better.

Researchers from Karolinska Institutet, Sweden have shown that participants who breathe through the nose consolidate their memories better.

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Memories pass through three main stages in their development: encoding, consolidation, and retrieval. Growing evidence from animal and human studies suggests that respiration plays an important role in the behavioral and neural mechanisms associated with encoding and recognition. Specifically nasal, but not the mouth, respiration entrains neural oscillations that enhance the encoding and recognition processes.

This is an emerging area of research. Such studies were not previously available as most common laboratory animals -- rats and mice -- cannot breathe naturally through their mouths.

“Our study shows that we remember smells better if we breathe through the nose when the memory is being consolidated -- the process that takes place between learning and memory retrieval," says Artin Arshamian, the researcher at the Department of Clinical Neuroscience, Karolinska Institutet. "This is the first time someone has demonstrated this."

The study participants were allowed to learn twelve different smells on two separate occasions. They were then asked to either breathe through their noses or mouths for one hour. When the time was up, the participants were presented with the old as well as a new set of twelve smells and asked to say if each one was from the learning session or new.

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The results showed that when the participants breathed through their noses between the time of learning and recognition, they remembered the smells better.

"The next step is to measure what actually happens in the brain during breathing and how this is linked to memory," says Dr. Arshamian. "This was previously a practical impossibility as electrodes had to be inserted directly into the brain. We've managed to get around this problem and now we're developing, with my colleague Johan Lundström, a new means of measuring activity in the olfactory bulb and brain without having to insert electrodes."

For reference log on to 10.1523/JNEUROSCI.3360-17.2018