Stutterers's Brain Not Organized

Stuttering that starts in childhood and continues into adulthood is uncommon. Those who find the condition lingering may be using a different part of their brain to process the speech.

The integration of hearing and motor function appears to play a role in speech fluency and which part of the brain does the processing.

Stuttering can be inherited, but stuttering that lasts beyond childhood may be the result of a brain injury, such as stroke or traumatic brain injury, or could have psychological causes.

Talk to your physician about speech therapy for persistent stuttering.

Dr. Nicole Neef and Dr. Martin Sommer from the University of Goettingen, and Dr. Bettina Pollok from the University of Duesseldorf, made the finding while studying the performance of a group of adults who stuttered, and comparing them to a group of adults who did not stutter in a finger tapping exercise.

Researchers used Transcranial Magnetic Stimulation to interfere temporarily with brain activity in the dorsolateral premotor cortex while the participants tapped their fingers in time to the clicks of a metronome. In the group that did not stutter, disturbing the left premotor cortex impaired the finger tapping, but disturbing the right premotor cortex had no effect. However, in adults who stuttered the reverse was true, and participants were unaffected when the left was disturbed.

Previously studies had linked stuttering with right-shifted cerebral blood flow in the motor and premotor areas during speech. But in the recent study, the shift to the right side of the brain happened even during a task that did not involve speech.

Investigators concluded this suggests a profound reorganization with the brain possibly compensating for subtle white matter disturbances in the left portion of the brain in those with a persistent developmental stutter.

The research was published in Cortex.