Introducing the brain: new motor control areas (Introduction)

by David Turell , Monday, May 15, 2023, 19:18 (556 days ago) @ David Turell

Combining action and emotions:

https://www.the-scientist.com/news-opinion/new-brain-network-connecting-mind-and-body-d...

"Even before speaking in front of a large crowd, your palms may start to sweat, your heart may race, and your shoulders may tense up.

"Little is known about why this happens, and how mental states, like emotions, influence the body in anticipation of an event. Now, however, researchers have identified a previously undiscovered brain network that might be behind this mind-body connection, according to new research published today (April 19) in Nature.

"'The newly discovered network involves both the motor cortex and cognitive areas of the brain, upending a long-held view that the motor cortex is only involved in producing movements.

“'The study is very interesting, very exciting,” says Michael Graziano, a neuroscientist at Princeton who was not involved in the study.

"The primary motor cortex sits in the back of the frontal lobes, near the temple. The dominant paradigm states that the motor cortex is simplistic. Planning, cognition, and conscious initiation of movements happen elsewhere in the brain; the motor cortex just receives these signals, relaying them directly to muscles.

"The motor cortex is organized in a way that correlates to a distorted representation of the human body called the cortical homunculus, where greater areas of the cortex are dedicated to parts of the body capable of fine motor control. This map is organized in an orderly fashion: the upper part of the cortex controls the toes, while the lower part, near the ear, controls the head. Study coauthor Evan Gordon explains that the homunculus is one of the most entrenched ideas in cortical neuroscience. “It’s one of the first things you learn about in grad school,” he says.

“'This map goes all the way [back] to 1870,” says Graziano, who studied the motor cortex for more than a decade. “We’re 150 years on from the discovery of this motor map. And it’s very traditional . . . and embedded.”

“'It’s also not true.”

***

"From this data, the researchers mined connectivity information in search of brain areas with coordinated activity, which could indicate that the areas were part of the same network. They found that the three newly discovered areas of the primary motor cortex connected to the cingulo-opercular network (CON), a brain region that’s been linked to action, goals, arousal, and pain. “We’ve thought about this network as one of the smartest networks in the brain because it does your high-level planning,” explains Gordon. The network also involved several other motor and sensory areas of the brain. Overall, they called this network the somato-cognitive action network, or SCAN, hypothesizing that the network connects goals, physiology, and body movement.

***

"The researchers found a similar network in nonhuman primates, using fMRI data from macaques. In monkeys, the SCAN was also connected to brain areas that control things like heart rate and breathing, leading the researchers to conclude that one of the network’s duties might be to put the body on alert in response to a stimulus, such as a stressful event."

Comment: we were evolved, so the same finding in nonhumans is no surprise. Also no surprise finding that such centers exist. We've all felt those emotions. That nonhumans have this pattern fits my idea that evolution follows broad patterns of development and therefore our brain will be a guide to lesser forms. And in my concept, our brain simply followed past patterns exactly. That is, past brains were oversized for initial use and complexified like ours. No past brain had the capacity to self-enlarge.