A group of 13- and 14-year old girls recently fell under a mass trance after attending a hypnotism act at their private high school in Quebec. The inexperienced 20-year-old hypnotist -- who claimed to have had about 14 hours of instruction -- had to call on his instructor to help snap the girls out of it, according to a CBC News report. 

The school principal later apologized to parents and students saying "they didn't know that 14-year-olds were more vulnerable to hypnosis than other people," and noted that all the girls are now fine, a Canadian press account reported.

But some of the girls complained of nausea and headaches shortly after the show, a sign that hypnosis shouldn’t be used as entertainment, says Dr. Joseph Zastrow, president of the American Society of Clinical Hypnosis and a family practitioner in Mooresville, N.C who teaches hypnosis and uses it in his medical practice.

"Stage hypnotists largely set a bad example to the public of what clinical hypnosis can do," says Zastrow. "We find it unethical to use hypnosis in a nonclinical fashion and certainly in the type of setting that it was provided in Canada," he adds. 

Zastrow says the American Society of Clinical Hypnosis provides hypnosis training but only to health professionals who have at least a master's degree  -- to psychologists, social workers, dentists, and doctors -- who will be using it as a tool in their practices. In addition to at least 60 hours of training, these practitioners also need to become board certified in hypnosis in their respective health field.

Using hypnosis as “fun and frolics,” is "like practicing medicine or psychology without a license,” Zastrow suggests, adding that doing hypnosis in groups is difficult to do properly.

There’s no magic to putting someone in a hypnotic state because a trance is a "natural extension of focus and attention," says Zastrow. Many of us are in a form of a trance when we daydream, or drive past our exit on the highway, or when professional athletes compete without being distracted by the crowd. 

By some estimates 5 to 10 percent of people are easily hypnotized and a roughly similar percentage are resistant to trance. The rest of us fall somewhere in between. Young people between the ages of 10 to 18 are at a prime age for responding to hypnotic suggestions and using these skills, says Zastrow.

Medical hypnosis has been most effective for pain control, such as for cancer-related pain, dental procedure pain, or the pain of childbirth, says Zastrow. Studies indicate it can ease symptoms of irritable bowel syndrome, and is effective for about 20 percent of people hoping to quit smoking.

When poorly trained entertainers – the types who make people quack like a duck or sing like Elvis – put teen girls into long deep trances, Zastrow believes "it besmirches the good deeds done every day by professionals using clinical hypnosis." 

More from The Body Odd:

• Why does music 'wake' some coma patients?
• Woman's stare reveals secret to hypnosis

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Alyssa Kramer can say any word backward.

Assyla Remark nac yas yna drow drawkcacb.

The 14-year-old from Poteau, Okla., can flip words around and spit them back out almost instantly -- it took me, on the other hand, like 45 seconds to just write that sentence backwards. 

Thanks to Alyssa's weird mental rewind button, she's become something of an Internet celebrity -- her YouTube video has gotten more than 1 million hits. 

Here's the video that launched Alyssa to mini-stardom.

OK, fine, she is maybe saying "huh?" to buy time when facing some of the longer words -- kaleidoscope, withdrawal, Lamborghini. But still -- impressive, right? Absolutely. But Andrew Levine can easily pu-eno Alyssa.

Levine, a research professor in philosophy at the University of Maryland at College Park, can speak entire sentences backward, in the four languages he knows (that's English, French, German and Italian, if you're interested) and in languages he's unfamiliar with. When asked what's happening in his mind when he speaks in backward gibberish, Levine can't say.

"If this girl is doing it the same way I'm doing it, it's nothing. It's like you're speaking another language," Levine says. "In fact, I think that I am effectively bilingual, in the sense that if you were genuinely bilingual, nothing would be going on in your brain." In other words, Levine doesn't consciously think, "TODAY: Y-A-D-O-T." He's just come to innately understand that TODAY backwards is YADOT, sort of like a person bilingual in Spanish and English knows that the words "today" and "hoy" are different ways of saying the same thing. 

About 30 years ago, Levine experienced a brief, weird brush with fame similar to the one Alyssa's experiencing now: He was a guest on "The Tonight Show" with Johnny Carson and was, he says, "a huge hit in Japan." He was also one of the subjects of a series of studies done back then on backward speech, conducted by Lewis Leavitt and then-graduate student Nelson Cowan.

Leavitt says he was curious whether a knack for reverse speech required an unusually strong memory; instead, they found it seems to require no particular special talents or heightened understanding of the English language. Backward-speakers like Levine seem to have taught themselves to hear each word sound-by-sound (or phoneme-by-phoneme, in academic speak). Alyssa, on the other hand, says she sees the word spelled in her head, and she's able to mentally flip it around and pronounce it.

"Backward speech is one of these things that seems to be an equal opportunity skill," explains Leavitt, who's now professor emeritus of pediatrics at University of Wisconsin, Madison. He illustrates this fact with some brief sketches of a handful of those study participants: a Stanford professor, a woman in the UK's House of Lords, a "German striptease artist." The stripper, incidentally, used to include backward speech in her act, and sent Levine a tape so he could check it out. "The striptease itself wasn't all that interesting, but her facility of backward speech was really quite impressive," Leavitt says.

The point is: Backward speakers come from all sorts of backgrounds, although they do have a few things in common. "They tend to be kids who do very well in school, who are smart and who have a decent-size vocabulary, but they are not necessarily kids who have a spectacular memory," Leavitt says. "So it's a skill that they practice, just like the violin."

Starting at around age 8 and tapering off around 13, kids tend to become interested in playing with language -- they might create their own language or make up one with a friend, or they might play around with backward speech. Most kids move on, but a few stick with it. Around this age, Leavitt explains, kids are getting huge bursts of brain power, while at the same time honing their social skills. That cognitive combo helps explain why this tends to be an age of all sorts of "obsessions," some more useful than others: Justin Bieber, "Twilight," a particular video game. In Alyssa's case, it seems backward speech may have been the thing to take hold.

"It's a combination of new cultural, as well as cognitive, prowess, and that's shown in a lot of their activities. And for some, it's developing certain special interests," Leavitt explains. "If you reflect back on your own childhood, you may even find something you were really into at that time." (A fascinating October episode of "This American Life" explores this idea in greater detail.)

In many cases, the things kids obsess over -- Bieber, backward talk, whatever -- may be helping them figure out where they fit in the world, but most of these esoteric interests aren't exactly going to lead to lucrative career options. Back in the early 1980s, when Levine appeared on TV and in newspapers all across the world, people kept telling him, Get an agent! Start an act!

He stuck with academia.

"It was funny 30 years ago," he remembers, "and if it had led to a career on 'Hollywood Squares' or something, I would've stayed with it." 

Can you (or a friend or family member) klat drawkcab? Brag about it on our Facebook page.

Related:

• Teen has tongue surgery to speak Korean. Huh?
• More college women speak in creaks, thanks to pop stars
• Pahking the cah? Regional accents getting stronger