A new study by researchers at Washington University School of Medicine in St. Louis suggests that the connection between the body and the mind is built into the structure of the brain. Research has shown that parts of the brain that control movement are connected to networks involved in thinking and planning, and control involuntary bodily functions such as blood pressure and heart rate.

Credit: Sara Moser/University of Washington

Practitioners of mindfulness say that when the action is quiet, the mind is quiet. The idea that body and mind are inseparable is more than just an abstraction, according to a new study by researchers at Washington University School of Medicine in St. Louis. Research has shown that parts of the brain that control movement are connected to networks involved in thinking and planning, and control involuntary bodily functions such as blood pressure and heartbeat. These findings suggest that in the structure of the brain, the body and the mind are indeed connected.

The study, published April 19 in the journal Nature, could help explain baffling phenomena such as why anxiety makes some people want to pace up and down? Why does stimulating the vagus nerve, which regulates internal organ functions like digestion and heart rate, relieve depression? And why do people who exercise regularly have a more positive outlook on life?

Gordon, PhD, assistant professor of radiology at the Mallinckrott Medical School and lead author of the study, said: “People who meditate say that by doing breathing exercises that calm your body, it also calms your mind. …these practices are really helpful for people with anxiety, but so far there hasn’t been a lot of scientific evidence on how it works. But now we’ve found the link. We’ve found the hyperactive, goal-directed Where the ‘go, go, go’ thinking part connects to the part of the brain that controls breathing and heart rate. If you calm one of them, it has a feedback effect on the other.”

Gordon and senior author Nico Dosenbach, Ph.D., did not set out to answer ancient philosophical questions about the relationship between body and mind. They set out to use modern brain imaging techniques to validate a long-established map of the brain’s regions that control movement.

In the 1930s, neurosurgeon Dr. Wilder Penfield mapped these motor regions of the brain by applying small electrical currents to the exposed brains of people undergoing brain surgery and recording their responses. He found that stimulating a narrow strip of tissue on either side of the brain caused specific body parts to twitch. Furthermore, the control regions in the brain are arranged in the same order as the body parts they control, with the toes at one end and the face at the other. Penfield’s map of the brain’s motor regions, depicted as a homunculus, has become a staple of neuroscience textbooks.

Several researchers set out to replicate Penfield’s work with functional magnetic resonance imaging (fMRI). They recruited seven healthy adults and had them undergo hours of fMRI brain scans while they were resting or performing tasks. From this high-density dataset, they built individualized brain maps for each participant. They then validated their results with three large, publicly available fMRI datasets—the Human Connectome Project, the Adolescent Brain Study of Cognitive Development, and the UK Biobank—that collectively contain around 50,000 Human brain scan.

To their surprise, they discovered that Penfield’s map wasn’t quite right. The feet, hands and face are positioned normally, but, in addition to these three key areas, there are three other areas that do not seem to be directly involved in movement at all, despite being located in the motor area of ​​the brain.

Furthermore, these non-motor regions look different than motor regions. They appear thinner and are closely connected to each other and to other parts of the brain involved in thinking, planning, mental arousal, pain and the control of internal organs and functions such as blood pressure and heart rate. Further imaging experiments showed that while the nonmotor regions were inactive during movement, they did become active when people thought about movement.

“All of these connections make sense if you think about what the brain really does, which the brain uses to successfully perform behaviors in the environment so that you can achieve your goals without injuring or killing yourself. You move your body There is a reason for that. Of course, the area of ​​motion has to do with executive function and control of basic bodily processes like blood pressure and pain. Pain is the most powerful feedback, right? You do something and you get hurt and you want to , ‘I won’t do it again.’”

Dosenbach and Gordon named their newly discovered network the Somato (body)-Cognitive (mind) Action Network, or SCAN for short. To understand how this network developed and evolved, they scanned the brains of a newborn, a 1-year-old and a 9-year-old child. They also analyzed data collected previously from nine monkeys. This network was undetectable in newborns, but evident in 1-year-olds and almost adult-like in 9-year-olds. Monkeys have a smaller, more rudimentary system, not as extensively connected as humans.

“It may have started with a simpler system that combined movement with physiology so that when we stood up, we didn’t pass out, but as we evolved to be able to think and plan more complexly,” Gordon said. organisms, the system has been upgraded to insert many very complex cognitive elements.”

Clues to the existence of this network have existed for a long time, scattered in isolated papers and puzzling observations.

“Penfield was brilliant, and his ideas were dominant for 90 years, which created a blind spot in the field, and once we started looking for it, we found a lot of published data that didn’t quite line up with his ideas, as well as being Other explanations that were overlooked. In addition to our own observations, we collected a lot of different data, narrowed and synthesized it, and came up with a new way of thinking about how the body and mind are connected.”

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A Somato-Cognitive Action Network alternates with effector regions in motor cortex

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