Introducing the brain: brain speech controls more complex (Introduction)

by David Turell , Wednesday, May 04, 2022, 22:36 (721 days ago) @ David Turell

New findings indicate diffuse control areas:

https://medicalxpress.com/news/2022-05-neuroscientists-multiple-brain-regions-speech.html

"Neurobiologists at the University of Pittsburgh School of Medicine give new meaning to the term "motor mouth" in a study published today in the Proceedings of the National Academy of Sciences. By carefully mapping neural networks in marmoset and macaque monkeys, they determined that multiple areas in the brain's frontal lobe control the muscles of vocalization and could provide a foundation for complex speech.

"The findings—which could lead to a better understanding of speech disorders—refute a long-existing presumption that only the primary motor cortex, nicknamed M1, directly influences the larynx or voice box, said principal investigator Peter L. Strick, Ph.D., Thomas Detre Professor and chair of neurobiology at Pitt. Instead, several cortical regions send signals to laryngeal muscles to create greater vocal finesse in some nonhuman primates.

"'This kind of parallel processing in our neural wiring might explain why humans are capable of highly sophisticated language that allows us to share information, express and perceive emotion, and tell memorable stories," said Strick. "Our remarkable speech skills are due to more evolved brains, not better muscles."

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"In addition to M1, both kinds of monkeys had multiple premotor areas in the frontal lobe that send descending command signals to the cricothyroid muscle. But two of the premotor areas provided a substantially larger source of descending output in marmosets, leading the researchers to propose that the enhanced vocal motor skills of marmosets are due, in part, to the expansion of neural signaling from these premotor areas.

"'This result challenges the long-held view that improvements in motor skills of vocalization are due largely to changes in the output from M1, the primary motor cortex," Strick said. "It appears there is no single control center, but rather parallel processing sites that enable complex vocalization and, ultimately, speech.'"

Comment: if monkeys have this complex arrangement, we have it. As usual the past in evolution always prepares for the future. God designs evolution in that fashion. Finally, dhw might come to recognize it as a form of common descent not described by Darwin