Stuttering may be more than a speech problem. A new study finds children who stutter have trouble identifying rhythmic drumbeats. “Stuttering has primarily been interpreted as a speech motor difficulty, but this is the first study that shows it’s related to a rhythm perception deficit — in other words, the ability to perceive and hear a beat,” says Devin McAuley, a psychology professor at the Michigan State University.
“That’s important because it identifies potential interventions which might focus on improving beat perception in children who stutter, which then might translate to improved fluency in speech,” adds McAuley, who is co-author of the study published in the journal Brain and Language. About 70 per cent to 80 per cent of children in the age group of 3 to 5 who stutter will eventually stop, McAuley says. Yet, despite decades of research, the underlying mechanisms behind speech disruptions in people who stutter remain unclear.
Rhythm and Speech
Being able to perceive and maintain a beat is believed to be critical for normal speech because it serves as a pacing signal. This is bolstered by past research showing that speech fluency improves dramatically for adults who stutter when speaking in time with a metronome. McAuley and colleagues tested a group of children who stuttered and a group who didn’t by having them listen to and then identify rhythmic drumbeats in the context of a computer game. Even after taking into account the kids’ IQs and language abilities, the study found that children who stuttered did much worse at judging whether two rhythms were the same or different.
Many past studies incorporated a motor skills element — such as having participants tap to a beat — which made it impossible to tell whether the problem was rhythm perception or a motor production deficit, McAuley says. The research team is integrating the behavioral data with functional magnetic resonance imaging, or fMRI, to identify which brain networks may be responsible for the rhythm perception deficit.
