December 5, 2013
Trickiest Tongue Twister Provides Insight Into Speech Planning
[ Watch the Video: This Tongue Twister Is The Trickiest Yet ]
Bryan Carpender for redOrbit.com - Your Universe Online
Forget that girl hawking her seashell wares on the beach. And that Peter Piper guy with his proclivity for pickled peppers is so 20th century. Those are the tongue twisters of yesteryear.
Psychologists at MIT have devised a new tongue twister, which they proclaim to be the most difficult and frustrating ever.
Pad kid poured curd pulled cold. That’s the phrase that researchers say will trip your tongue up more than any other. Go ahead -- try saying it right now. (You know you’re already doing it.) It’s not that easy, is it?
According to the team from MIT, this tongue twister is so tricky that volunteer research subjects couldn’t even get through it. Some stumbled after a few tries, while the majority simply froze up and were rendered speechless.
"If anyone can say this [phrase] ten times quickly, they get a prize," said Stefanie Shattuck-Hufnagel, an MIT psychologist who studies speech errors as a way of understanding normal brain functions, in a statement.
However, it turns out that tongue twisters (and the inevitable word salad that come as a result of speaking them) are good for more than just laughs – they can provide scientists with valuable insights into the brain’s speech-planning process.
"When things go wrong, that can tell you something about how the typical, error-free operation should go," she said.
Research shows that that when certain combinations of sounds are spoken too quickly, people seem to lose control of their mouths. Often, one sound seems to replace another:
"Toy boat" becomes "toy boyt."
"Top cop" becomes "cop cop."
And things really go off the rails with this one:
"The seething sea ceaseth and thus the seething sea sufficeth us" – it just becomes a mess of misplaced "s's" and "th's."
When the misspoken sounds were recorded and analyzed, scientists found that the errors were not always straightforward sound replacements.
At least some of the time, the mistakes didn't seem to be quite one sound or another, but something in between with more variations. In the "top cop" example, sometimes the "t" and the "c" seemed to arrive almost at the same time (sort of "tkop") and sometimes there was a delay between the two, with space for a vowel ("tah-kop"). These double sound mistakes are referred to as double onsets.
The team from MIT – along with their colleagues at Haskins Laboratories in New Haven, Conn., Ludwig-Maximilians University in Munich, Wellesley College in Massachusetts, and the University of Southern California (USC) in Los Angeles – tried to determine whether they could induce different types of double onset with different types of tongue twisters.
The researchers recorded volunteers saying combinations of alternating words that fell into two categories: simple lists of words such as the "top cop" example above, and full-sentence versions of the same sounds with an inversion, such as "the top cop saw a cop top."
After recording their volunteers' efforts, the researchers analyzed the sounds to see what errors people had produced. They found that in the word list tongue twisters, there was a preponderance of the "t'kop” errors. In contrast, the sentence twisters induced more of the "tah-kop"-type errors, with the longer delay and the presence of a short vowel after the consonant.
According to Shattuck-Hufnagel, it’s too early to say exactly what is responsible for these differences, but one possible factor is the regular rhythm of the word lists compared to the more irregular timing of the sentences.
Whether in the sentences or the word lists, the fact that both types of errors occur suggests that there is some overlap between the brain processes used to produce these two types of speech. "You can get both kinds of errors in both kinds of planning," she said, but the different proportion of errors indicates key differences as well.
The MIT team and their colleagues are already working on the next stage of the study, which will measure speech articulation by placing tiny transducers on the soft palettes of research subjects.
The researchers hope to uncover more information about double onsets in which the tongue has tried to make both a "t" and "k," but only one sound is heard. If these double onsets are indeed more likely to be produced by word list twisters than by sentence twisters, Shattuck-Hufnagel said, then this work will help scientists understand how the brain plans these two types of speech.
While we wait for the results of that study, we can still practice wrapping our mouths – and brains – around the current titleholder for trickiest tongue twister.
Repeat after me: Pad kid poured curd pulled cold.
Now say it ten times, as fast as you can.