New study shows movement, emotion and planning are linked in the brain : Shot

The seemingly simple act of reaching for a cup of coffee actually activates parts of the brain involved in movement, planning, and emotion.

Melinda Podol/Getty Images

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Melinda Podol/Getty Images

The seemingly simple act of reaching for a cup of coffee actually activates parts of the brain involved in movement, planning, and emotion.

Melinda Podol/Getty Images

The seemingly simple act of reaching for a cup of coffee requires a lot of effort from your brain.

You have to plan your trajectory to the cup, control dozens of muscles, make adjustments based on feedback from your eyes and fingers, and stay focused on your goals.

And it turns out that medical textbooks may be wrong about how all this happens. increase.

But a scientist at the Washington University School of Medicine in St. Louis found it A previously overlooked region of the brain’s motor cortex appears to link control of specific muscles with information about the entire body and brain.

As a result, the act of reaching for a cup of coffee, for example, can directly affect blood pressure and heart rate. .

However, textbooks still depict “motor cortex where the area that controls the fingers is not connected to the area”. [that asks]say “What are you going to do today?” Dr. Nico Dosenbachauthor of the study and Associate Professor of Neurology and Radiology.

But the MRI data leaves little doubt that there is this interconnected system. Evan Gordon, Assistant Professor of Radiology and the first author of the study. “It was always there, but we weren’t aware of it because of training and what we learned in our first neuroscience class.”

Previewed result online 2022 has received a lot of interest and support from neuroscientists and neurosurgeons.

“I think this is a really fundamental shift in how we look at the motor cortex,” he says. peter strickChair of Neurobiology, University of Pittsburgh.

Challenge common sense

This discovery involves a strip of brain tissue called the primary motor cortex. As its name suggests, this region is considered the primary source of signals that control voluntary movements.

Textbooks show the primary motor cortex as a continuous ribbon with sections dedicated to specific muscle groups from the tongue to the toes.

That view dates back to the 1930s. wilder penfield began mapping the brains of epileptic patients by applying electrical currents to regions of the motor cortex. Ultimately, Penfield identified segments that reliably moved the feet, fingers, or tongue.

Penfield’s hand drawn map Although several teams have pointed out, since then the primary motor cortex defect along with some details.

So Dosenbach’s team was stumped when they started finding hints of very different organizations. Clues came in the form of data from high-resolution functional magnetic resonance imaging (fMRI) of individual brains.

What they saw “wouldn’t make sense if the textbook was correct,” says Dosenbach.

Gordon noticed that the MRI data suggested significant regions between Penfield’s sections. These areas of the cortex had many connections, but not the muscles. Instead, connections led to areas throughout the brain, including those that controlled internal organs such as the heart and lungs.

At first Gordon doubted what he was seeing. He wondered: “Is this something strange about the data we collect, or does it exist for others?”

So the team began analyzing fMRI data collected by other groups. It confirmed their own findings.

“A heretical idea began to take hold that maybe this was right and this book was wrong,” says Dosenbach.

But if these parts of brain tissue weren’t meant to control muscles, what were they doing? To find out, the team turned to chief scientist Nico Dosenbach. I was.

“We put Nico in the scanner for a long time and had him do different things until we figured it out,” Gordon says with a laugh.

They had Dosenbach perform complex tasks such as rotating his left hand in one direction and his right leg in the opposite direction. His brain had to plan his movements before performing these tasks.

Experiments have revealed surprising things about the mysterious spread of brain tissue.

“At this planning stage, we found that these areas of the motor cortex were more active, and that steered us in the right direction,” says Gordon.

Another brain region called the premotor cortex is known to play a role in planning movements, but the region discovered by Gordon and Dozenbach’s team is woven into the primary motor cortex itself.

“We have two interleaved systems,” says Dosenbach. For example, just below the area that controls the fingers, the team finds areas involved in “whole-body integrated actions.”

The team then combed through several large databases that combine many MRI scans to show connections in a typical brain.

Gordon also found evidence that ribbons in the motor cortex contain alternating areas for fine control of specific muscles and areas for tracking the whole body.

The team began sharing its findings with other scientists. Among them is Strick, who has observed a similar system in monkeys in the lab.

“Sometimes you have this aha experience,” he says.

A new look at the primary motor cortex could help explain how the brain solves tough problems, says Strick.

“Even simple movements require subtle control over every organ system,” he says. “You have to control your heart rate. You have to control your blood pressure. You have to control what you call the fight-or-flight response.”

Therefore, it makes sense that the same ribbons of brain tissue involved in movements such as standing up are connected to all other brain regions.

A system that interweaves movement and mental states may also explain why posture changes with mood, and why exercise makes us feel better.

“How you move can affect how you feel, and how you feel will affect how you move,” Strick says. “You see, my mother used to tell me, ‘Stand up, you’ll feel better.’ And maybe it’s true.”