Short Wave - Babies got beat: Why rhythm might be innate

Episode Date: February 6, 2026

Rhythm is everywhere. Even if you don’t think you have it, it’s fundamental to humans’ biological systems. Our heartbeat is rhythmic. Speech is rhythmic. Even as babies, humans can track basic rhythm. Researchers wanted to find out if there were more layers to this: Could babies also track melody and more complicated rhythms? So they played Bach for a bunch of sleeping newborns and monitored the babies’ brains to see if they could predict the next note. What they found offers clues about whether melody and rhythm are hard-wired in the human brain or learned over time. We also get into what powers the eating habits of some snakes and chameleons, and insights into the role of sleep in problem-solving.Have a scientific question you want us to answer? Email us at [e-mail] to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Listen to Short Wave on Spotify and Apple Podcasts. This episode was produced by Jordan-Marie Smith and Rachel Carlson. It was edited by Rebecca Ramirez and Christopher Intagliata. Tyler Jones checked the facts. The audio engineers were Jimmy Keeley and Hannah Gluvna. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, short wavers, Regina Barber here. And Rachel Carlson. And today we have our biweekly science news roundup featuring the hosts of all things considered. And today we have one of my favorite gamers, Juana Summers. Hello, excited to be here. So I heard y'all that we were talking about babies listening to Bach to see if they can perceive rhythm and melody just after birth. Yep.

Plus a finding that could tell us more about why reptiles feed on very different time scales. compared to humans. And the old adage, sleep on it, may actually help you solve a problem. All that on this episode of Shortwave, the science podcast from NPR. Okay, Wana, where do you want us to start? Okay, I want to start off with music and babies, Rachel. Yeah, okay. So scientists know that even as babies, we can track basic rhythm like this.

But they didn't know how primed our youngest minds were to perceive melody or more complicated rhythms like this. all the way to complicated drum solos. Interesting. Okay, so how did scientists test this? In a study out this week in Plox biology, scientists played piano music by Bach to sleepy newborn babies. And the babies were hooked up to these EEG machines to see how well their little brains predicted rhythm or the melody. Love this. So what did they find? They were looking for brain signals that show the babies were predicting the next note. In adults, our brains predict both the rhythm and the melody of the music.

next note. But they found that the babies tracked the rhythm, even though it could get pretty complicated. But the babies didn't track the melody. Interesting. So does that mean that babies have rhythm at birth, but not melody? Seemingly, possibly? And do they have an idea as to why we might have this sort of innate sense of rhythm really early in life? Yeah, we also talk to Laurel trainer about that. She's a developmental neuroscientist at McMaster University. She studies music perception. And she said it's likely because rhythm is everywhere. Babies crawl rhythmically. They flail their arms rhythmically. Their heartbeats are rhythmic. So in biological systems, rhythms are just fundamental to everything, from movement to proceeding things like speech or

music to thinking. So she says it makes sense that predicting rhythm is an ancient trait. After all, she points out the babies are exposed to rhythm in the womb through the mother's heartbeat and walking. But melody, on the other hand, isn't present at birth, at least not in the part of the brain where the scientists were looking. But just because the scientists didn't see it doesn't mean it's not there. And we should note that this study only looked at Western classical music. Interesting. Okay. Let's go to our next topic.

And there's a clue about snakes and hunger, I understand. I am not the biggest fan of snakes, but I'm willing to go on this journey with you. Snakes freak me out. But they are extraordinary when it comes to their feeding patterns. Some can go without food for months or even a year. Right, and then they'll eat a huge meal, right? Yeah, exactly. My brother honestly does this, so I call it his snake meal.

But researchers haven't understood if there's a genetic piece to why snakes and some other reptiles do this. But now they might have a clue. Researchers looked at the genomes of over 100 reptile species and found some snakes and chameleons have lost the genes that produced the hunger hormone ghrelin. And humans have that too, right? That's why I'm hungry right now. Yeah, yeah, we do. It's all part of this hormonal system of appetite in humans. As Grelin levels rise in our bodies, we get hungry.

I just satisfied mine. I just had a sandwich. It's also involved in how much we eat and body weight regulation. And you've probably heard of another appetite hormone, GLP1. Right. Yeah, it's sort of like Grellon's counterpart. It tells us when we're full. So what does this mean for snakes if they don't produce this hunger hormone?

The researchers think this finding could tell us more about why snakes are able to fast for months. And the study was published this week by the Royal Society. I talked to another evolutionary biologist who wasn't involved in this study. His name's Alex Pyren. And he told me, studying these kinds of metabolic pathways in reptiles could tell us more about humans in the future, with more research. Bonus trivia, Juana, did you know that GLP1 drugs like Ozempic were inspired in part by research on Gila monster venom? I did not know that. Yeah, it's super cool.

So sometimes animal studies can have surprising payoffs. All right, let's move on to our third topic. And this one I'm excited about because I love sleep and I have a lot of problems that need solving. And I hear that sleep might help. Yeah, I mean, when I was in college, I would dream about difficult quantum mechanics problems. And it turns out it might have helped me. We learned during the day very effectively, but to really make it stick, we need something additional. And some of that's happening during sleep.

That's Ken Pallor, a cognitive neuroscientist at Northwestern University. And he and his team studied this by working with 20 lucid dreams. So people who are sometimes aware that they're dreaming, which I'm very jealous of. And they ask them to solve brain teasers or puzzles or riddles. Like, here's one of them. Can you find a meaning or a cute way to interpret this set of letters, G-E-S-G? I literally have no ideas. Please help me.

We're going to let that one simmer. We'll marinate. We'll make about it for a while. Yeah. And in the meantime, I'll tell you more about the study. So the scientist only gave the volunteers three minutes to solve puzzles like this, which usually wasn't enough time. And then they also played a unique soundtrack while people were solving each puzzle. And Juana, as you stare at these letters like G-E-S-G in confusion, imagine like also hearing this song.

The idea was to help people's brain link the puzzle to a sound or a song, and then the participants were told to go to sleep. Huh. And then what happened when they went to sleep? So the scientists monitored the sleepers, and once they entered REM sleep, the researchers would play that unique soundtrack cue to do a little inception. They wanted to encourage dreaming about that specific puzzle that they hadn't been able to solve when they were awake. So what did they find? Can you solve puzzles in your sleep like Gina? Well, after the volunteers woke up, they were more than twice as likely to solve puzzles they dreamt about compared to puzzles they didn't remember dreaming about. So, yeah, the results are published in the journal Neuroscience of Consciousness. Speaking of which, Wana, did you have an answer for a riddle from earlier, like looking at these letters G-E-S-G?

No, I didn't have time to sleep on it, and I'm just really bad at these. Do you want the answer? I am too. Okay, the answer is scrambled eggs. Well, now I'm just hungry again. How do you get scrambled eggs out of G-E-S-G? Because it spells eggs. It smells eggs, but they're mixed up.

I didn't get it either, honestly. Okay, but the bigger point isn't the answer to this one puzzle that stumped all of us. It's that these scientists are one step closer to answering that age-old question. Like, why do we dream? Like, what is it for? And according to Robert Stickold, another dream researcher that didn't work on the study, dreams aren't just entertainment. They're a catalyst for processing information and inducing creativity.

Very interesting. You've given me something to think about when I doze off later tonight. Yeah. Hopefully it's not work. Hopefully not. I want to thank you so much for coming on our show and having so much fun with us, solving puzzles. Yeah, next time we'll have more puzzles.

Oh, no. I'm still not going to be good at them, but I will bring my best. best game. You can hear more of Wana on Consider This and PR's Afternoon podcast about what the news means for you. And for more science stories just like this one, follow Shortwave on whatever app you're listening to. I produced this episode alongside Jordan Marie Smith and Burley McCoy. It was edited by Christopher Entaliata and Rebecca Ramirez. Hannah Glovna and Jimmy Keely were the audio engineers. I'm Regina Barber. And I'm Rachel Carlson. Thanks for listening to Shortwave, the science podcast from NPR.

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