A Look At The Science Behind Stuttering

MINNEAPOLIS (WCCO) -- That feeling of holding yourself back from finishing the sentence of a person who stutters -- we've all been there. On this National Stuttering Awareness Week, WCCO Radio is doing a five-part series on the communication disorder that affects 70 million people worldwide, three million here in the U.S. alone. Here's Laura Oakes with Part 2 of "Speech Interrupted: The Science of Stuttering."

The severity of stuttering ran the gamut at a recent National Stuttering Association Twin Cities chapter meeting.

"My biggest situation is probably on the phone. That's probably my most challenging situation," said Judy, one of the attendees at the meeting.

"A lot of times I avoid certain letters. Or, I avoid the very first letter of some words," said Bill, another attendee.

But the one thing nearly all said is the most frustrating for them? When people they're trying to communicate with visibly show their discomfort when the words just won't come out. Looking away is the most common non-verbal cue.

So, what causes stuttering? While there's no definitive answer, experts do know it has something to do with a discrepancy between the right and left hemispheres of the brain.

Anne Boever is a Speech and Language Pathologist with North Memorial Medical Center.

"The gist of it is, there seems to be more activity in the right hemisphere for people who stutter, compared to people who don't stutter, who typically have all their speech and language in the left hemisphere. So something is activated in the right hemisphere. They're thinking that part of that is because there are some weaker areas in the left hemisphere for people who stutter, and so, perhaps, the right hemisphere is activated to help with that," Boever said.

Boever says researchers haven't found one specific area of the brain that causes stuttering, but where they have found weakness on the left side, it's been primarily along a fiber tract that connects the areas that control speaking, language processing, and motor skills.

Boever says stress, which stutterers battle all day long, can make stuttering worse.

"I will work with people who, if they're more tired, or if they had a stressful day the day before, just like the rest of us, when we're kind of stressed out, certain things don't work as well for us. We don't think as easily, and we're maybe even a little more disfluent then. For someone who stutters, it's going to affect that in a bigger way," Boever said.

But for stutterers like Danny, another attendee at the NSA meeting, all the science in the world can't fix a problem that has affected them psychologically for much of their lives.

"Most of the struggles with my speech impediment that I deal with are really within my head. I mean, I beat myself up a lot."