Neuroscientists have discovered sections of the language pathway responsible for speech in the brains of primates, which split off from the branch of apes 25 million years ago. The results of the study are published in the journal Nature Neuroscience.
Although speech and language are unique to humans, it is believed that the basis for auditory cognition and vocal communication originated in the brain of the common ancestor of apes and humans, and this happened about five million years ago.
Scientists from Europe and the United States analyzed the auditory zones and pathways of the brain in humans and various monkeys, not only anthropoid, but also those whose evolutionary paths diverged from hominoids 25 million years ago, and in representatives of all branches of primates, a so-called linguistic region was found in the brain. a pathway that connects the auditory cortex to areas of the frontal lobe important for speech and language processing.
"I admit that we were amazed to see this pathway in the auditory system of nonhuman primates," the study leader, Chris Petkov, a professor of medicine, quoted a press release from Newcastle University. whether the human language path had such a long evolutionary basis."
For neuroscientists, the comparative study of the physiology of adjacent species is comparable to the search for ancient fossils used by paleontologists. By comparing the brains of living primates and humans, biologists judge what their common ancestors were.
Now they understand that the origins of such a unique tool as the language that a person uses for communication and cognition dates back a very long time. But in the brain of which representative of ancient mammals this happened, scientists do not yet know.
"It's like looking for a long-lost ancestor," says Petkov.
Scientists also managed to find a key difference between the auditory and linguistic features of the human brain - its left side turned out to be stronger than the right side, which, according to scientists, deviated from the auditory evolutionary prototype in the process of evolution, and in it the non-auditory parts of the brain were involved in the language pathway.
The study was based on brain scans of humans and other primates from the open resources of the global scientific community. The authors hope that their findings will inspire scientists to replenish these databases with new scan results, which will allow neuroscientists to continue their search for the origins of human speech and find out which other animals have fragments of the language pathway in the brain.
"This discovery has tremendous potential for understanding which aspects of human auditory cognition and language can be studied in animal models, as it cannot be done directly in humans or apes," notes first author Timothy Griffiths, consultant neurologist from Newcastle University.