What is it that causes people to stutter? Researchers at the University of Alberta’s Institute for Stuttering Treatment and Research (ISTAR) in the Faculty of Rehabilitation Medicine may have an answer. A study, led by Dryk Beal, ISTAR’s executive director, has found a key brain difference in children who stutter: they have less grey matter in the area of the brain responsible for speech production.
Previous research into the etiology of studying have often focused on examining the differences in the brains of adults and children who stutter. However, there is no way to determine which areas of the brain are inherent to studying and which have developed from a lifetime of coping with the condition. For the ISTAR study, the researchers only focused on children in order to learn which areas of the brain are related to stuttering from childhood.
The researchers scanned the brains of 28 children aged five to 12; half were diagnosed with a stutter and the other half served as the control group.
The scans of the children who stutter exhibited abnormal development in a region called the interior frontal gyrus. This is key because this section of the brain is thought to manage articulatory coding—the interpretation of brain signals for language into speech movements. These results also underscore the need for early treatment.
“If you think about the characteristics of stuttering—repetitions of the first sounds or syllables in each word—it’s easy to hypothesize that it’s a speech-motor control problem … 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,” explained Beal.
This research is published in the journal Cortex.