Hyperactive centre makes us stutter
About 1 % of all adults stutter, and now, scientists are trying to find out why. Several studies indicate that stuttering is caused by interruption of the cooperation between two brain centres located on either side of the frontal lobe. In the left cerebral hemisphere, the centre controls our speech motions, whereas the same centre in the right cerebral hemisphere impedes speech.
Scientists from the Max Planck Institute in Germany have scanned the brains of stutterers, as they imagined that they were stating the names of months. A control group was asked to do the same thing. The results showed hyperactivity in the right brain centre of stutterers, impeding the activity in the left one. In non-stutterers, the activity was much more balanced.
The explanation of stuttering is probably to be found in the right cerebral hemisphere. The scans also revealed that the stutterers had a particularly active bundle of nerve threads that originates from the right brain centre. The more a test subject stuttered, the higher the activity of the nerve bundle. It is probably those very nerve threads that carry impairing signals from the right to the left cerebral hemisphere, causing stuttering.