Tongue twisters were always something fun to do when growing up. Who can say it the fastest? Who can say it the most times? Who is the best? It was something fun to do with friends and would always take up some time when you started getting into it.
To figure out if it was the brain mixing up the syllables or if it was coming from the mouth, in 1982 researchers Ralph and Lyn Haber conducted a study asking participants to read two types of sentences, one containing a tongue twister, and one that was complex but did not contain a twister. They found that participants slowed down in sentences with tongue twisters even if their tongue wasn’t in use, this would be sounds like “p” and “b”. This says that the brain is confusing the sounds before they even get to your mouth.
To further this research, in 2013 a team from the University of California put electrodes in the skull of epilepsy patients to record electrical activity in the brain. They found that the neural patterns that lit up when they pronounced consonants were different from when they pronounced vowels, even though they are using the same tract. They also found that the brain split phonemes into 3 groups- front of tongue, back of tongue, and vowels. Sounds formed in the same area are easier to switch up, which is why twisters like “sally sells seashells” are harder to say.
Another group of researchers from MIT had participants say a combination of words in two categories- one of them was simple words like, “Top Cop” and the other one was a sentence of words like, “The Top Cop Saw a Cop Top.” After some trials, here was one set of words that they found most participants had a struggle with, and when asked to say it multiple times they gave up, this list was, “Pad Kid Poured Curd Pulled Cod” and it might be the hardest tongue twister to say.
So why are tongue twisters so hard so say, and what makes this one especially difficult? They said that tongue twisters have qualities that the brain tends to reject, a string of quick but distinct phonemes. They analyzed the participants saying the twisters and found that the most common mistakes came from double onsets, like ‘Top Cop’ becoming ‘tkop’ or ‘toy boat’ becoming ‘tuh boyt’. This suggests that there is an overlap in brain processes used in speech. The research at MIT hasnt been finished, but they hope to to find more connections in the use of double onsets and the types of speech.