Neurology and Stuttering

Abstract: Demonstration of deviating patterns of brain activity in stutterers provide the possibility of new treatment methods Helena Forne-Wästlund, Speech-language and hearing pathologist

Background - neurology

All monitoring of speech functions and motor activities, concerning our speech, is controlled by a complicated network in our brain. The most complex motor process is the fine-motor control that coordinates our breathing and the movement of our speech organs producing speech. By way of a complex system of collaborating connections, a number of parallel messages are sent to the speech muscles containing information on the performance of a specific movement. At the same time, a sensor feedback is given whether the motor movement has been correctly performed and in what position the speech muscle is.

Stuttering is caused by a defective coordination and timing between breathing, voicing and articulation, which leads to a lacking control of the speech.

Over the last 30 years, researchers have arrived at the conclusion that the fluency can be improved significantly in a person who stutters by offering speech therapy in which a correct motor pattern is developed and a conscience is built of the physical sensation characterising this pattern.

In the case of children and people with a very mild or mild stuttering, a complete cure is often possible by way of an intensive treatment and the continuous use of the correct motor pattern. This is called automation. People who stutter moderately to severely can realistically expect a significant improvement in their fluency provided they apply the techniques in their daily conversation. From a communication viewpoint, a dramatic change can be observed in those who apply the techniques diligently. A transition from very severe to very mild stuttering is certainly possible. These people will probably always have to think about the techniques when they speak and will thus be able to successively improve the fluent pattern of speech.

From about the mid 1990s, it has become possible to register brain activities while an assignment is being carried out. This technique provides a great opportunity for us to enhance our knowledge of different disorders and it enables us to control these functions or compensate for a loss of one of these - by way of training. Recent research demonstrates that certain parts of the brain, the motor speech centre (the Broca area) and the centre for anxiety readiness (Anterior Cingulate Cortex), are involved in stuttering and its rehabilitation.

Throughout the world, research projects are conducted trying to map cerebellum’s functionality and other areas of the human brain by those who stutter, compared with normal speakers. (co-ordination and movement patterns etc)

In 1998, the researchers Kroll and de Nil of the University of Toronto conducted a Brain Map radiology examination of the brain’s activity of people who Stutter in comparison with Normal Speakers. The survey demonstrated that persons who stutter displayed highly increased activities in their right cerebral hemisphere in the Broca area when reading aloud or to themselves compared with persons who do not stutter. Besides, people who stutter displayed remarkably high activities in the Anterior Cingulate Cortex when reading aloud or to themselves, a fact that is possibly due to an anxiety readiness in the stuttering person confronted by the risk of having a blockage.

After the survey, the persons who stutter underwent a speech training programme of three weeks according to the PFSP method and were subsequently able to register a substantial improvement in their fluent speech. At the scanning immediately after the treatment, highly reduced activities could be detected in the Broca area to the right side as well as substantially increased activities in the Broca area, left side. The activity in the Anterior Cingulate Cortex had practically disappeared.

The speech training sessions continued for one year and the subsequent scanning demonstrated activities in the brain that had become more like that of normal speakers displaying normal activities in the left Broca area and no activity in Anterior Cingulate Cortex. Unlike normal speakers, the activities still displayed low readings in the right section of the Broca area.

Training with the computer

Method

In 1997, the project "Computer-based Speech Training of People who Stutter" was initiated under the management of the Swedish Handicap Institute (Forne-Wästlund 2001) with a view to repeating the positive treatment results in Sweden. The Project introduced a completely different view of stuttering. As opposed to the traditional view of stuttering according to which stuttering was considered mentally determined and treatments such as the Non-Avoidance Treatment (NA) and psychotherapy were used, stuttering was now considered a physiologically determined disorder.

At the same time, the speech training method, Precision Fluency Shaping Program (PFSP) and the treatment method Comprehensive Stuttering Program (CSP) were introduced in Sweden. In the speech training method PFSP, the person who stutters undergoes a three-week intensive treatment, learning the principles of fluent speech and becomes aware of the movements and functions of the speech organs. First by exercising syllables of a duration of 2 seconds after which the speech rate is gradually increased until the normal 120-160 syllables per minute.

Results and conclusion

See the results in next section: Summary of the Swedish report.

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