By Crystal Goh, neuroscientist and writer. 

We know that nasal breathing is calming. Research now indicates it may also improve cognitive function. 

We’re all familiar with the advice “Just take a deep breath” when emotions run high. Science has confirmed that slow, deep breathing calms by reducing heart rate and activating the parasympathetic (calming) nervous system. The result? Your body relaxes and your mind quiets. 

Breathing through your nose may enhance that effect. Through a series of experiments, scientists at Northwestern Medicine discovered that nasal breathing plays a pivotal role in coordinating electrical brain signals in the olfactory “smell” cortex—the brain regions that directly receive input from our nose—which then coordinates the amygdala (which processes emotions) and the hippocampus (responsible for both memory and emotions). During nasal inhalation, the fast electrical rhythms in both became stronger. In a final experiment, when showed images, people had better recall later on if they first encountered the images on an inhalation through the nose. 

So the in-breath specifically alters your cognition, improving both emotional and memory processing. What about the out-breath? The good news is that any slow, steady breathing—like the kind employed in meditation and yoga—activates the calming part of the nervous system, and slows heart rate, reducing feelings of anxiety and stress. The act of slow, deep breathing, whether the inhalation or exhalation, is beneficial for your nervous system when you wish to be more still. 

Keywords; nasal breathing, relaxation