Taking a deep breath through the nose stimulates the brain
Taking a big breath in when trying to remember could be a simple way to boost recall, scientists believe, after finding that inhaling stimulates the brain.
US researchers discovered that the rhythm of breath creates electrical activity in the brain where emotions, memory and smells are processed.
In experiments, individuals were able to identify a face two seconds more quickly if they encountered it when breathing in compared to breathing out.
They were also more likely to remember an object if they encountered it on the inhaled breath, rather than the exhaled one.
But the effect disappeared if breathing was through the mouth.
“One of the major findings in this study is that there is a dramatic difference in brain activity during inhalation compared with exhalation,” said lead author Dr Christina Zelano, assistant professor of neurology at Northwestern University Feinberg School of Medicine in Chicago, Illinois.
“When you breathe in, we discovered you are stimulating neurons in the olfactory cortex, amygdala and hippocampus, all across the limbic system (which controls instinct and mood). When you inhale, you are in a sense synchronising brain oscillations across the limbic network.”
Scientists at Northwestern first discovered the differences in brain activity while studying seven patients with epilepsy who were scheduled for brain surgery.
A week prior to surgery, a surgeon implanted electrodes into the patients’ brains in order to identify the origin of their seizures.
But it also allowed scientists to acquire electro-physiological data directly from their brains. They discovered that their brain activity fluctuated with breathing.
To test whether inhaling could impact memory, 60 volunteers took part in an experiment where they were asked to rate whether a face showed a fearful or surprised expression. When faces were encountered during inhalation, subjects recognised them as fearful more quickly.
The same subjects were also shown pictures of objects on a computer screen and told to remember them. Later, they were asked to recall those objects. Researchers found that recall was better if the images were encountered during inhalation.
“If you are in a panic state, your breathing rhythm becomes faster,” added Dr Zelano.
“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 study was published in the Journal of Neuroscience.