
Brains of parrots, unlike songbirds, use human-like vocal control
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Singin' in the brain Brains of parrots, unlike songbirds, use human-like vocal control A parrot called the budgerigar controls its vocalizations with a flexible system. John Timmer Mar 19, 2025 4:44 pm | 2 Credit: Serega Credit: Serega Story textSizeSmallStandardLargeWidth *StandardWideLinksStandardOrange* Subscribers only Learn moreHuman speech arises courtesy of some significant neural horsepower. Different areas of the brain are involved in determining the meaning that's desired, finding the words to express it, and then converting those words to a specific series of soundsand all that comes before the correct sequence of nerve impulses is sent to the muscles that produce the final output. Humans are far from alone in the animal kingdom with an impressive range of vocalizations, though. That raises the prospect that we can understand a bit more about our own speech by studying how vocalization is managed in different animals.One group of species that's especially interesting is birds. They're distant relatives compared to other animals with interesting vocal capabilities, like whales and elephants, and their brains have some notable differences from ours. They also show a range of behaviors, from complex songs to vocal mimicry to whatever it is that you want to call what parrots do. Thanks to a newly released study, however, we now have evidence that these different types of vocalization are the product of different control systems in the brain.The study relied on electrodes placed in the brains of parrots and songbirds and tracked the behavior of neurons in a region that controls vocalization. It showed that the two relied on different types of control, with parrots having a system that operates similarly to the one used by humans.Timing isnt everythingThe work focused on two species of birds. One is the zebra finch, a songbird that learns to produce a short song it uses each year, in part by listening to what its peers are singing. The second is the budgerigar, a small parrot that's often kept as a pet. Budgerigars are both impressive vocal mimics and also have complex vocalizations called warbles that are a mix of noisy and harmonic calls.Due to past work, we've already identified the brain structure that controls the activity of the key vocal organ, the syrinx, located in the bird's throat. The new study, done by Zetian Yang and Michael Long of New York University, managed to place fine electrodes into this area of the brain in both species and track the activity of neurons there while the birds were awake and going about normal activities. This allowed them to associate neural activity with any vocalizations made by the birds. For the budgerigars, they had an average of over 1,000 calls from each of the four birds carrying the implanted electrodes.For the zebra finch, neural activity during song production showed a pattern that was based on timing; the same neurons tended to be most active at the same point in the song. You can think of this as a bit like a player piano central organizing principle, timing when different notes should be played. "Different configurations [of neurons] are active at different moments, representing an evolving population barcode," as Yang and Long describe this pattern.That is not at all what was seen with the budgerigars. Here, instead, they saw patterns where the same populations of neurons tended to be active when the bird was producing a similar sound. They broke the warbles down into parts that they characterized on a scale that ranged from harmonic to noisy. They found that the groups of neurons tended to be more active whenever the warble was harmonic, and different groups tended to spike when it got noisy. Those observations led them to identify a third population, which was active whenever the budgerigars produced a low-frequency sound.In addition, Yang and Long analyzed the pitch of the vocalizations. Only about half of the neurons in the relevant region of the brain were linked to pitch. However, the half that was linked had small groups of neurons that fired during the production of a relatively narrow range of pitches. They could use the activity of as few as five individual neurons and accurately predict the pitch of the vocalizations at the time.Structural similaritiesBoth of these birds use a specific region of the brain to control the muscles of the syrinx to produce a series of sounds. But they organize that process completely differently. The zebra finch has neurons that trigger the right muscles for a given time within the songeven if a similar sound needs to be produced earlier or later. By contrast, the budgerigar organizes things so that the same neurons fire whenever a similar tone needs to be produced; the timing of the tone within a warble is apparently handled elsewhere."Our finding of a universal motor representation in the budgerigar forebrain indicates that AAC neurons do not represent the individual vocalizations per se," Yang and Long write, "but instead the underlying motor processes that generate thosevocalizations."That's in keeping with the budgerigar's warbles, which are more tonally complex than a typical songbird vocalization and aren't repeated with the same sort of consistency as the zebra finch's song.And that's similar to how the last step in human speech production is handled; earlier steps in the process break down our vocalizations into individual sounds, and a specific region of the brain is devoted to producing the right anatomical configuration to produce them. It's important to emphasize that this doesn't mean the budgerigar's warbles are like language; we don't currently know what's upstream of this translation step in these birds and whether that has any parallels in humans.The other big open question is what drove the budgerigar and its relatives to develop a system so unlike that of the zebra finch. It's possible that complex calls were being selected for, and the ancestors of parrots evolved this system to fill that need. But it's equally possible that this organization came about for some other reason or entirely by chance, and the birds simply started using it to produce more complex calls.Nature, 2025. DOI: 10.1038/s41586-025-08695-8 (About DOIs).John TimmerSenior Science EditorJohn TimmerSenior Science Editor John is Ars Technica's science editor. He has a Bachelor of Arts in Biochemistry from Columbia University, and a Ph.D. in Molecular and Cell Biology from the University of California, Berkeley. When physically separated from his keyboard, he tends to seek out a bicycle, or a scenic location for communing with his hiking boots. 2 Comments
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