Nose-breathing boosts memory, study finds

How the study tested the effect of nose-breathing on memory

One stumbling block to understanding how breathing through the nose affects the brain is that scientists' typical subjects — mice and rats — don't breathe through their nose. Therefore, sniffing out the truth of the matter requires human subjects. And, appropriately enough, the experiments involved smells.

The study's 24 subjects memorized 12 smells delivered through a nasal cannula during two training sessions. Afterward, they were given an hour off during which they were instructed to breathe exclusively through either their mouths or noses.

This was followed by exposure to a variety of scents, some of which were from their training sessions and some of which were new. Subjects were asked to differentiate between the two.

What the scientists found was that those who'd breathed through their noses during their hour off were more likely to recognize the scents from training sessions, suggesting that their nose-breathing had more effectively stored what they'd learned.

Next steps

Easier research implicated receptors in the olfactory bulb that can detect both scents and variations in airflow. Scientists have also seen different areas of the brain exhibit activity during inhaling and exhaling, but how this all ties together is as of yet unknown.

Arshamain tells KI News:

"The next step is to measure what actually happens in the brain during breathing and how this is linked to memory. This was previously a practical impossibility as electrodes had to be inserted directly into the brain. We've managed to get round 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."