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We’ve all been tripped up by tongue-twisters. That’s the whole point! But at a neuroscientific level, they’re as difficult to understand as they are to say.

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This episode is sponsored by Fabulous, an app that helps you form healthy habits that stick.

Click the link in description to get a free week trial and 25% off a Fabulous subscription! [♪ INTRO] “She sells seashells by the seashore.” Ok. What about “The seething sea ceaseth and thus the seething sea sufficeth?” We’ve all been tripped up by tongue-twisters.

That’s the whole point. And at a neuroscientific level, they’re as difficult to understand as they are to say. But studying how we mess up words has told scientists some pretty surprising things about how our brains process sounds and letters to make language.

Tongue twisters appear to be a universal phenomenon of spoken language. And that’s because speaking requires some really complicated choreography involving multiple parts of the body. Like, if you’re reading aloud, one area of the brain processes the written words.

Then it relays commands to your vocal cords, diaphragm, tongue, and lips, telling them to form sounds, move air, and make the correct shape of your mouth to produce speech. So there’s a lot of places that things can go wrong when you’re trying to say “Clean clams crammed in clean cans.” Now at first, scientists weren’t sure whether getting tongue-tied occurred at the brain level or whether it occurred as a mechanical issue that happens in the mouth. So in a 1982 study, researchers told participants to silently read tongue twisters.

And they found that their brains read the tongue twisters much more slowly than they read easier sentences. Now that suggests the brain struggles with tongue twisters before the tongue even gets involved. So, possibly we should be calling them brain twisters.

I don’t think we’re gonna change the name, though. Still, some sequences of sounds are more difficult to produce than others. People slip over similar-sounding vowels, like “toy boat, toy boat, toy boat, toy boat.” And the same thing happens with similar-sounding consonants.

For example, one of the trickiest tongue-twisters in the world was coined by a team of MIT scientists led by Stefanie Shattuck-Hufnagel. And no, it was not just saying her name three times fast. The phrase is: “Pad kid poured curd pulled cod.” “Pad kid poured curd pulled cod.” But, why, why is it hard for us to put those consonants together?

Researchers have also wondered this. And it turns out it’s linked to how your brain thinks about letters. Scientists discovered this in a remarkable 2013 study published in the journal Nature.

The study involved three epileptic people who previously had electrodes implanted in their brains to help with their condition. The researchers were able to use those electrodes to measure the subjects’ brain waves while they spoke, giving them a more detailed look at what happens in the brain during speaking than anyone had ever gotten. And it revealed that neurons fire in different patterns for consonants versus vowels.

This seems a little surprising, because consonants and vowels use the same areas of your vocal tract. And you might think the difference between them seems, like, purely academic. That’s something we defined.

But actually, the brain processes these groups of letters differently. And then, it further categorizes sounds according to the muscles the mouth uses to make them. Consonants are also, by your brain, lumped into three categories: front-of-the-tongue sounds like “sa,” back-of-the-tongue sounds like “ga,” and lip sounds like “ma.” Meanwhile, the brain separates vowels into sounds that require rounded lips, like “oo,” and sounds that don’t require rounded lips, like “aa.” And that is why, when you’re saying a tongue twister, you’re more likely to confuse sounds in the same category.

So, you’ll end up swapping one consonant for another consonant, rather than swapping a vowel for a consonant. And you’re more likely to mess up consonants that are articulated in the same part of your mouth. Like “ta” and da” or “s” and “sh” rather than “g” and “sh.” Now, this particular study was conducted in English.

But since all languages have vowels and consonants, it’s likely that this kind of separation of sounds in the brain is widespread or even universal. Though, we’ll need more research to determine how people categorize different sounds in different languages. And, there are also lots of things about tongue twisters that can still stump scientists.

Like, people make different kinds of errors when they read a list of tricky words than when they are saying complete tongue-twisting sentences. Why? We’re not sure yet!

Also, bilingual people tend to trip over tongue-twisters more than monolingual people. But that can depend on how long they’ve spoken the language and what kinds of sounds are involved. What’s up with that?

Also more research needed! Digging into these mysteries and learning more about tongue twisters will help us deepen our understanding of cognition and talking. And it could also help people who struggle with speech, which, sometimes, is all of us.

Tongue twisters aren’t just neat for scientists to study. If you practice them regularly, you can actually improve your pronunciation! Of course, forming habits is also hard.

Luckily, Fabulous can help. Fabulous is the number #1 self care and habit forming app on the app store with over 20 million users. And it’s actually based on behavioral science research!

So it can really help you incorporate tongue twisters into your daily routine, or, anything else you might want to do more regularly, like drinking more water or stretching when you wake up. The app is totally customizable, so it’s really up to you! And you can start building your ideal daily routine today!

Because the first 100 people who click the link in the description will get a free one-week trial and 25% off a Fabulous subscription! [♪ OUTRO].