Take a deep breath. It will affect how well you remember this story. And if you have a cold and are stuffy, well, that might alter how you perceive this story, too, because if you inhale through your mouth rather than your nose, that will change things. Don’t believe me? Check out the findings from this recent study, conducted by researchers at the Northwestern University Feinberg School of Medicine.
They found that the rhythm of breathing—inhaling or exhaling and whether that breathing is conducted via the nose or mouth—changes electrical activity in the brain, either enhancing or hindering judgment and memory.
Here’s how the study worked. The researchers asked 60 subjects—who wore a face mask that looks like something you might see on someone with sleep apnea—to make a decision about a picture of a face they saw on a computer screen, as quickly as they could. Was the human face showing the emotion of fear or surprise? When the subjects were shown the pictures of faces when they were inhaling, they were able to assess the true emotion of the face more quickly than when they were exhaling. But, the effect diminished when the subjects inhaled through their mouths.
To test memory, the subjects were shown pictures of objects and asked to remember them. Again, their skills were sharper when they were inhaling, but only when they were inhaling through their noses.
“One of the major findings in this study is that there is a dramatic difference in brain activity in the amygdala and hippocampus during inhalation compared with exhalation,” wrote lead author Christina Zelano, Ph.D., an assistant professor of neurology at Northwestern University Feinberg School of Medicine. “When you breathe in, we discovered you are stimulating neurons in the olfactory cortex, amygdala and hippocampus, all across the limbic system.”
“If you are in a panic state, your breathing rhythm becomes faster,” Zelano wrote. “As a result you’ll spend proportionally more time inhaling than when in a calm state. Thus, our body’s innate response to fear with faster breathing could have a positive impact on brain function and result in faster response times to dangerous stimuli in the environment.”
The big takeaway? If you are feeling threatened or stressed, keep breathing through your nose, as you’ll be able to respond with a clear head.