Introducing the brain: special neurons for music, singing (Introduction)

by David Turell , Tuesday, February 22, 2022, 19:49 (794 days ago) @ David Turell
edited by David Turell, Tuesday, February 22, 2022, 20:24

Just discovered:

https://www.newscientist.com/article/2309238-there-are-neurons-in-the-brain-that-only-s...

"Humans may have neurons whose main job is to process singing. Scientists have previously found neurons that are selective for speech and music, suggesting that our brains have specific cells that handle different types of sounds we hear.

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"...the researchers discovered a population of neurons that seemed to respond nearly exclusively to singing, although they also had a very small response to speech and instrumental music.

“'This work suggests there’s a distinction in the brain between instrumental music and vocal music,” says Norman-Haignere, although the researchers didn’t test whether the neurons also responded to spoken word or rap music.

"They overlaid these results with fMRI data from 30 other people who listened to the same sounds so that they could map the neurons to a specific region of the brain. The “singing” neurons were located roughly between the music and speech-selective areas of the auditory cortex.

"The researchers don’t know why we would have such neurons. “It could have been due to some evolutionary role,” says Norman-Haignere. “Many people think that singing has some important role in the evolution of music.” (my bold)

“'But it’s also totally possible that it’s all driven by exposure,” he says. “People spend a huge amount of time listening to music.” The team is confident that these neurons aren’t driven by musical training and that we all probably have them.

“'To be able to distinguish the musical properties of sounds is fundamental for survival,” says Jörg Fachner at Anglia Ruskin University in Cambridge, UK. “It makes sense that this dispositional ability is wired into our auditory cortex.”

“'It may also explain why singing a beloved song to a person with dementia may allow responses [even though] the neurodegenerative process has limited the functionality of brain areas,” he says. “This result, along with other neuroimaging-related results of musical memory, may help to explain why songs may help dementia patients.'”

Comment: if the neurons were specialized from the beginning perhaps they were part of the original design in anticipation of music and singing. Based on primitive tribes, they mostly use rhythm not the musical scale. Another article:

https://medicalxpress.com/news/2022-02-neuroscientists-population-neurons-brain-music.html

"For the first time, MIT neuroscientists have identified a population of neurons in the human brain that lights up when we hear singing, but not other types of music.

"These neurons, found in the auditory cortex, appear to respond to the specific combination of voice and music, but not to either regular speech or instrumental music. Exactly what they are doing is unknown and will require more work to uncover, the researchers say.

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"For those participants, the researchers played the same set of 165 sounds that they used in the earlier fMRI study. The location of each patient's electrodes was determined by their surgeons, so some did not pick up any responses to auditory input, but many did. Using a novel statistical analysis that they developed, the researchers were able to infer the types of neural populations that produced the data that were recorded by each electrode.

"'When we applied this method to this data set, this neural response pattern popped out that only responded to singing," Norman-Haignere says. "This was a finding we really didn't expect, so it very much justifies the whole point of the approach, which is to reveal potentially novel things you might not think to look for."

"That song-specific population of neurons had very weak responses to either speech or instrumental music, and therefore is distinct from the music- and speech-selective populations identified in their 2015 study.

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"The song-specific hotspot that they found is located at the top of the temporal lobe, near regions that are selective for language and music. That location suggests that the song-specific population may be responding to features such as the perceived pitch, or the interaction between words and perceived pitch, before sending information to other parts of the brain for further processing, the researchers say."

Further comment: this article makes deliberate design of this small brain area more reasonable to assume.