Breathing is not just for consuming oxygen; it’s also related to brain function and behavior.
Northwestern Medicine scientists have found for the first time ever that the rhythm of breathing causes electrical activity in the human mind that boosts emotional judgments and memory recall.
These influences on behavior are based on whether you inhale or exhale and whether you breathe through the mouth or the nose.
In the research, each person was able to identify a fearful face faster if they saw the face while breathing in compared to breathing out. Additionally, individuals were more likely to recall an object if they encountered it on the inhaled breath than on the exhaled one. Interestingly, the effect vanished if breathing was through the mouth.
“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,” said lead author Christina Zelano, 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.”
The study was published Dec. 6 in the Journal of Neuroscience.
The senior author is Jay Gottfried, professor of neurology at Feinberg.
Northwestern scientists first found these differences in brain activity while examining 7 patients with epilepsy who were scheduled for brain surgery. A week before the surgery, a surgeon implanted electrodes into the patients’ brains to identify the origin of their seizures. That gave scientists the opportunity to acquire electro-physiological data directly from their brains. The electrical signals proved that brain activity fluctuated with breathing. The activity takes place in brain areas where feelings, memory and smells are processed.
The discovery led scientists to ask if cognitive functions typically related to these brain areas — especially fear processing and memory — could also be influenced by breathing.
The amygdala is strongly connected to the emotional processing, especially fear-related emotions. So scientists asked about 60 individuals to make quick decisions on emotional expressions in the lab environment as their breathing was being recorded. While looking at pictures of faces expressing either fear or surprise, the individuals had to tell, as fast as they could, which feeling each face was expressing. (NeuroscienceNews.com picture is for illustrative purposes only.)
When faces were shown during inhalation, subjects recognized them as fearful faster than when faces were shown during exhalation. This was not the case for faces expressing surprise. These results decreased when individuals performed the same task while the breathing was through the mouth.
In another experiment — tied to the hippocampus — the same individuals were looking at pictures of objects on a computer screen and tried to remember them. Later, they were asked to describe those objects. Researchers discovered that recall was better if the pictures were shown during inhalation.
According to Zelano, the discoveries indicate that fast breathing may offer an advantage when somebody is in a dangerous situation.
“If you are in a panic state, your breathing rhythm becomes faster,” Zelano said. “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.”
Another potential result of the research is on the main mechanisms of meditation or focused breathing. “When you inhale, you are in a sense synchronizing brain oscillations across the limbic network,” Zelano noted.