How does breathing alter the brain? Inside the science of sighs with a world-leading neuroscientist

SEPTEMBER 12, 2026 07:49You are doing it right now, and until I mentioned it, you were not aware of it. We all take breathing for granted. As Prof. Henry Higgins described Eliza Doolittle’s habits, joys, and woes in My Fair Lady, they “are second nature to me now, like breathing out and breathing in.”In less than the time it took you to read these two sentences, a tiny cluster of neurons in your brainstem called the preBötzinger complex fired a synchronized burst of electricity. That signal raced down to your diaphragm, causing it to contract, dropping the air pressure in your lungs and pulling in a fresh wave of oxygen.We tend to think of breathing as the body’s background software – a monotonous, automatic gas exchange running silently in the basement while the brain handles the “important” work of thinking, feeling, and deciding up in the penthouse.But groundbreaking neuroscience shows that the relationship is actually a brisk, two-way street. Every single time you inhale or exhale, it isn’t just keeping you alive; it is actively rewriting your brainwaves, sharpening your memory, and dictating how you process the world around you.Balloon breathing (credit: SHUTTERSTOCK)Prof. Jack Feldman flew to Israel for the first time to attend and be a guest speaker at last week’s Hebrew University Faculty of Medicine’s Institute for Medical Research Israel-Canada (IMRIC) Conference at the Dan Carmel Hotel.IMRIC is the university’s central medical research institute, conducting cutting-edge research across a broad range of fields related to human health and disease, including the nervous system and brain, diabetes, cancer, infectious diseases, embryonic development and regeneration, and many other areas of biomedical science.Feldman is one of the world’s leading experts on breathing and the brain. His studies have been published not only in prestigious scientific and medical journals; they have also been featured in The New York Times, NPR, and Scientific American.Feldman received his bachelor’s degree in physics from Polytechnic Institute in New York and a doctorate in physics from the University of Chicago. He went on to perform experimental neuroscience for a postdoctoral fellowship in Paris and a second one in New York. In 1978, he began his first academic appointment as assistant professor at Northwestern University in Illinois, and in 1986, he moved to the University of California at Los Angeles (in southern California), where he is a distinguished professor of neurobiology.In 1991, together with co-researchers at Stanford University in northern California, Feldman elucidated the mechanisms underlying breathing and sighing and discovered and named the preBötzinger complex and identified the central brain circuit that generates and controls sighing.His research explores the connections among breathing, stress, anxiety, emotions, sleep, and meditation, focusing on a particularly interesting and timely question: Can changing the way we breathe actually change the way we feel?We normally think the brain tells the diaphragm and other respiratory muscles what to do, but Feldman’s work is helping establish that the relationship also goes the other way: breathing to the brain to create a person’s emotional/cognitive state.The mechanisms of breathingIn an interview with The Jerusalem Post during a break in the conference, he explained that the brain’s sigh control center contains two tiny clumps of about 200 neurons in the brainstem (located in the preBötzinger complex) that convert normal breathing into a sigh. These neurons use specific neuropeptides (NMB and GRP) to signal the brain’s breathing engine to double the volume of an upcoming breath.“Besides regular breathing, other things have to overtake this system. It’s not simple. We think we know how nature does it. Why should breathing affect your emotions, without oxygen and carbon dioxide?”The alveoli – the minuscule, grape- or cauliflower-like air sacs at the end of the air passages in your lungs where oxygen is exchanged for carbon dioxide at the end of the smallest breathing tubes, called bronchioles – are only one cell thick, creating a very short path for gases to move.“Their surface area,” Feldman continued, “is about 75 square meters – a third of a tennis court, so there is a lot of gas exchange. The circuit involved makes us sigh every five minutes on average. When you’re stressed, many things happen in the brain. When the hypothalamus produces peptides, you sigh more. It’s natural and essential to sigh.“In the early 1950s, when children who were infected with polio were put in iron lungs to breathe, the technicians created bigger breaths with fewer per minute. That reduced the exchange. They figured out that instead of large lung volumes, there should be a normal one, and then let the child sigh every once in a while. It maintains the health of the lungs.”He once asked a neuroscientist’s assistant how often one sighs. She said it was rare – maybe two per day, when one is sad or stressed or happy – but she was wrong.“A sigh is a deep breath, but not a voluntary deep breath,” he asserted. “It starts out as a normal breath, but before you exhale, you take a second breath on top of it. On average, a person sighs every five minutes.”The research demonstrated that sighing is a critical, unconscious survival mechanism rather than just an emotional expression. Sighing every five minutes on average is an involuntary “physiological sigh” – a double inhalation followed by an extended exhalation – which re-inflates the alveoli, preventing lung collapse and maintaining adequate gas exchange, he said.Breathing exercises began thousands of years ago, Feldman stated.“The people of China and India meditated, as did residents of indigenous cultures. I originally studied physics and cosmology, but then I got interested in how the brain works. My academic adviser said the topic was too difficult. Then, as a graduate student, I took LSD about once a month. It took a while before it was banned as a psychedelic. I became interested in the perception of space and time and read about neuroscience.”He had thought that “breathing was trivial – just simple rhythm – but it’s far from trivial.”“We breathe for many reasons,” he said. “The heart is only a pump, but breathing does a lot of things, and it begins from the third trimester in the womb. If one has a normal lifespan, you breathe about a billion times in life. It takes many seconds to double your heart rate, but you can do this with breathing.”Hoping to help peopleRats sigh 20 times more when peptide is added, said Feldman, who conducts much of his research on rodents.“Over three days, we got mice to breathe slowly at our command – five minutes a day for 30 days in a chamber. Then we put them back in the cages and measured their fear response. Those that breathed slowly had a much lower fear response. They were much calmer. So breathwork can also make humans calmer; breathing changes everything in the brain.”A single deep breath is relaxing: “If you are a small animal being chased by a predator, you take one or more deep breaths to calm you down. You will be less detectable to the predator and have a better chance to survive.”He has demonstrated all this in animals, and hypothesizes about what might eventually be clinically useful.“I want to help people, but I don’t research humans. I want to understand the brain and influence human health through others who treat them,” he explained. “Breathwork – slow breathing at a set pace on inhalation, holding it, and then slowly exhaling – disrupts activity. It may reduce depression. Deep brain stimulation rebalances the circuit.”He is well aware of the fact that people want quick cures, “but they are resistant to breathwork because they don’t think it’ll help. But they will realize it is real. You don’t have to believe in something – just do it. I recommend people do breathwork five minutes a day for 30 days and see if it helps them.“It may even influence cognition as well as emotion – for example, attention, memory, or decision-making – and could possibly improve patients in the early stages of Parkinson’s disease or dementia.”He was very pleased by the IMRIC conference because it was multi-disciplinary, bringing together some 400 researchers and physicians from Israel and abroad who specialize in cancer, immunology, biology, and more."This is beneficial, because researchers in the room next to your lab at home could be doing something relevant to your research and you wouldn’t have known about it.”He conceded that he had never been to Israel in his long career, even though he is in touch with Israeli colleagues.“It didn’t work out. Now, the University of California doesn’t let anybody go to the Middle East because of the supposed danger, including in Israel,” he shared. “I had to apply for and get special approval to come. It’s very interesting to be here for seven days. What is really happening in this country is not well communicated in the US.”Follow us on Google