The way we breathe may affect how well our memories are consolidated.
The way we breathe may affect how well our memories are consolidated (i.e. reinforced and stabilised). If we breathe through the nose rather than the mouth after trying to learn a set of smells, we remember them better, researchers at Karolinska Institutet in Sweden report.
Research into how breathing affects the brain has become an ever-more popular field in recent years and new methodologies have enabled more studies, many of which have concentrated on the memory. Researchers from Karolinska Institutet now show that participants who breathe through the nose consolidate their memories better.
One reason why this phenomenon has not previously been available for study is that the most common laboratory animals, rats and mice, cannot breathe naturally through their mouths.
For the study, the researchers had participants 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.
The results showed that when the participants breathed through their noses between the time of learning and recognition, they remembered the smells better.
New method facilitates measuring activity in the brain
Earlier research has shown that the receptors in the olfactory bulb detect not only smells but also variations in the airflow itself. In the different phases of inhalation and exhalation, different parts of the brain are activated. But how the synchronisation of breathing and brain activity happens and how it affects the brain and therefore our behaviour is unknown. Traditional medicine has often, however, stressed the importance of breathing.