Breathing is so automatic that it feels almost mindless. Many assume that our daily rhythmic respiration occurs in a smooth, even pattern. But it turns out, the way people fill their lungs with air is rather idiosyncratic.
“Every breath is a little bit different, even at natural breathing,” said Bradley Voytek, a professor of cognitive science at UC San Diego. “We pause for 10 seconds at a time, sometimes the breaths will be shallow, sometimes you might sigh.”
In a recent study, Voytek and his team found that regions in the brain associated with memory, cognition and emotion, can track those small changes that occur in each breath. The detailed comparison showed that the relationship between the human brain and breathing is more tightly linked than previously thought.
Mapping the shape of each breath against neural signals may uncover warning signs for fatal events like sudden death in epilepsy (SUDEP) in the future.
“That shape, every couple of seconds, the brain activity really mirrors it really closely, and so, what that means or where do we go from here leads to a lot more open options for next steps in research,” Voytek said.
The researchers published the paper in the Journal of Neuroscience in late August.
Scientists have known that breathing is connected to how we feel. Previous research has shown that popular controlled breathing techniques, such as boxed breathing, can improve mood and help manage stress. Breathwork has also been integrated into ancient practices like yoga and meditation for centuries.
But uncovering the underlying mechanisms driving is more difficult to identify.
“We have a sense culturally and experientially that these things help and there is scientific evidence that breath control can calm emotions and things like that, but in terms of what those are doing to the brain and brain activity … that’s the layer that we’re trying to add the extra layer of clarity,” Voytek said.
To further investigate respirations' direct impact on brain activity, the researchers measured both air flow and neural signals in patients with epilepsy. Each patient already had an implant in their brain to help record seizures unrelated to the study. The electrodes could measure voltages from neurons in regions of the brain that are difficult to access.
Noninvasive methods, such as placing electrodes on top of a patient's head, can only provide information about the surface regions of the brain. But measuring signals deeper in the brain gets convoluted.
“It’s like trying to understand a conversation that two people are having by holding up a microphone outside of a domed football stadium,” Voytek said. “Like you can hear people cheering and stuff like that, but can’t tell who is saying what and where, you just know that something happened.”
By working with the patients who had already undergone invasive brain surgery, Voytek and his team could record information from regions located deeper in the brain. Each voltage was represented on a graph by a squiggly line.
The team also measured the patient's breathing using either a belt around their chest or a device to measure air flow past their nostrils. Eena Kosik-Rose is a graduate student in Voytek's lab. When she mapped the brain activity to each of their corresponding breaths, she found that the two lines mirrored each other almost perfectly.
“I completely didn’t believe it, I was like there’s something wrong with my data. Am I coding something wrong?” she said. “I said I'm in my sixth year of my PhD, it's basically because there’s been a lot of disbelief along the way.”
The coupled effect showed that the way people breathe may be tightly tied to brain activity in regions known for cognition, memory and emotion. While the insight is relatively preliminary, Voytek believes this high resolution understanding of the mind and body could lay the foundation for exciting new research.
One future implication may include investigating breathing stops during fatal events like sudden death in epilepsy (SUDEP) and sudden infant death syndrome (SIDS). Though rare, some patients with epilepsy or infants may die unexpectedly. The cause of these casualties is unknown. However, irregular breathing is suspected to play a role. Looking into the relationship between the brain and breathing may one day be able to help develop an early warning system.
“By creating this approach and refining this approach of measuring the fine scale shape of each breath, we’re hoping to be able to extend that clinically to be able to look at can we predict when a SUDEP or SIDS event occurs because of irregular change in the shape of the breathing,” Voytek said.
He noted that this type of advancement is still a long way away from becoming a reality. However, the new finding may be able to one day reveal clues about the causes of these mysterious breathing related deaths.
