A recent study from researchers at the Washington University School of Medicine in St. Louis, published in the journal Nature, provides scientific evidence that the body and mind are “inextricably intertwined.” According to the research, certain regions of the brain that manage movement are connected to networks that are associated with cognitive processing, decision-making, and regulating automatic bodily functions like heart rate and blood pressure.
The study reveals a direct and physical connection between the body and mind, otherwise known as the mind-body connection, within the brain’s architecture, which researchers are calling a “literal linkage”.
The research has significant implications as it provides an explanation for various puzzling phenomena. For instance, it could clarify why individuals experiencing anxiety tend to pace back and forth, why stimulating the vagus nerve could alleviate depression, and why regular exercise is linked to a more positive outlook on life.
Evan M. Gordon, PhD, an assistant professor of radiology at the School of Medicine’s Mallinckrodt Institute of Radiology and lead study author, explained that calming practices like breathing exercises are helpful for people with anxiety. “People who meditate say that by calming your body with, say, breathing exercises, you also calm your mind,” Gordon explained.
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However, scientific evidence for how these practices work has been lacking. Gordon said that the research findings now provide a link between the highly active, goal-oriented part of the brain and the areas that control breathing and heart rate. Therefore, calming one of these areas should have positive effects on the other.
Measuring the mind-body connection
The study used modern brain-imaging techniques to replicate famous neurosurgeon Wilder Penfield’s work from the 1930s, which mapped the motor areas of the brain by stimulating them with electricity during brain surgery and observing the responses. The study aimed to validate the long-established map of the brain regions responsible for controlling movement.
The research team and colleagues recruited seven healthy adults to undergo hours of fMRI brain scanning while resting or performing tasks. From this high-density dataset, they built individualised brain maps for each participant. They then validated their results using three large, publicly available fMRI datasets — the Human Connectome Project, the Adolescent Brain Cognitive Development Study, and the UK Biobank — which together contain brain scans from about 50,000 people.
But to the researchers’ surprise, they discovered that Penfield’s map of the brain’s motor areas was not entirely accurate. The section he identified as controlling the feet, hands, and face was correct, but interspersed within these three areas were three additional regions that did not appear to be involved in movement at all, despite being located within the motor area of the brain.
“Penfield was brilliant, and his ideas have been dominant for 90 years, and it created a blind spot in the field,” said Nico Dosenbach, MD, PhD, associate professor of neurology and study author.
“Once we started looking for it, we found lots of published data that didn’t quite jibe with his ideas and alternative interpretations that had been ignored.” Dosenbach explained that the team then pulled together different data sets in addition to their new observations, and “zoomed out and synthesized it, and came up with a new way of thinking about how the body and the mind are tied together.”
In addition to the surprising discovery of non-movement regions within the brain’s motor area, the researchers found that these regions differed in appearance from the regions responsible for movement. Specifically, the non-movement regions appeared thinner and were strongly connected to other areas of the brain responsible for a variety of functions, including cognition, emotion, and regulation of internal organs.
These findings suggest that the non-movement regions may be involved in a broader range of bodily processes than originally thought.
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Mind-body connection: SCAN
The research group coined the term “Somato-Cognitive Action Network” (SCAN) to refer to their newly discovered cognitive processing or mind-body network. To investigate the development and progression of this network, they used brain scans of a newborn, a one-year-old, and a nine-year-old, as well as data from nine monkeys that had previously been gathered.
The SCAN was not discernible in the newborn, but it was “distinctly” present in the one-year-old and almost fully developed in the nine-year-old. The monkeys had a smaller, less intricate system without the extensive interconnections observed in humans.
“This may have started as a simpler system to integrate movement with physiology so that we don’t pass out, for example, when we stand up,” Gordon said. “But as we evolved into organisms that do much more complex thinking and planning, the system has been upgraded to plug in a lot of very complex cognitive elements.”
Some incredible neuroscience discoveries have been announced over the last few years, fundamentally shifting our understanding of how the human brain manages such complex systems throughout the body. Gordon and colleagues now join a growing list of champions contributing to this understanding.