Researchers evaluated 28 children between the ages of five and 12 who underwent MRI brain scans. Half of the children had been diagnosed with stuttering and the others acted as a control group.
The brain scans revealed that the children who stuttered had abnormal development of the inferior frontal gyrus region of the brain.
It's believed that this region takes information that the brain understands about language and sounds and codes it into speech movements.
Study author Deryk Beal, executive director of the Institute for Stuttering Treatment and Research at the University of Alberta, said: "If you think about the characteristics of stuttering – repetitions of the first sounds or syllables in a word, prolongation of sounds in a word – it's easy to hypothesise that it's a speech-motor-control problem."Previous research examined structural differences between the brains of adults who stutter and those who do not. The problem with that approach was that the brain scans come years after the onset of stuttering, typically between the ages of two and five, Beal said.
"You can never be quite sure whether the differences in brain structure or function you're looking at were the result of a lifetime of coping with a speech disorder or whether those brain differences were there from the beginning," Beal explained.
He said the results of his study were a first step toward testing to see how the amount of gray matter in the brain was influenced by treatment for stuttering and for understanding motor-sequence learning differences between children who stutter and those who don't.
"The more we know about motor learning in these kids, the more we can adjust our treatment -- deliver it in a shorter period of time, deliver it more effectively," Beal said.
The Nemours Foundation has more about stuttering.
Photo of embarrassed child from Shutterstock