Oct 25, '05: New Research Study: Effects of Exercise on Stuttering (Online survey now available)
The Study
We are conducting a survey to investigate the relation between regular exercise and stuttering frequency and severity. Participation is voluntary and participants will be anonymous. This study is approved by the Institutional Review Board of New York Medical College, Valhalla, NY. Any questions should be addressed to Dr. Ben Watson (914) 594-4821 or ben_watson@nymc.edu.
This survey is now available online by clicking here.
Background
Stuttering is a complex disorder which interrupts the flow of speech. It is a condition in which the speaker repeats sounds and prolongs syllables in an irregular manner. People who stutter have several core characteristics that include, but are not limited to, blocking, which is characterized by a stutterer’s speech coming to a halt; repetition, in which sounds, syllables or words are repeated; and prolongations, in which a sound is extended beyond a normal duration. Facial expressions may alter due to tension in the lips, jaw, tongue, and upper chest. In moments of intense distress, the head may jerk uncontrollably. These secondary behaviors occur as a reaction to or in anticipation of the core stuttering behaviors described above. People who stutter avoid speaking situations such as placing phone calls and meeting new people.
Scientists are still attempting to discover the cause of stuttering. A commonly held theory is that stutterers’ left striatum is hyper-sensitive to dopamine or that stutterers have an excess of dopamine (Wu et al, 1997; Goberman & Blomgren, 2003). There is experimental evidence that lowering the levels of dopamine results in a decrease in stuttering (Maguire et al, 2000).
Dopamine is a neurotransmitter that is associated with reward, addiction, emotions, pleasure, pain, and movement control. It is produced in the substania nigra and assists motor functions (Alm, 2004). Dopamine interacts with numerous other neurotransmitters. For example, dopamine and serotonin balance each other. If serotonin levels are raised, dopamine levels become lowered and visa versa.
When a person exercises, multiple neurotransmitters are released in the brain. One of these is the endorphins. Endorphins are a natural pain killer and are released from the pituitary gland when the body is under stress or in pain. Another neurotransmitter released is serotonin. Serotonin affects appetite, emotions, sleep and anxiety.
In sum, (1) excess dopamine has been linked to stuttering behavior; (2) there is an inverse relationship between levels of dopamine and serotonin; and (3) serotonin and endorphins are released during sustained exercise. The question under test in this study is whether daily, intensive exercise results in improved fluency in persons who stutter. If so, such a finding would provide indirect support the role of excess dopamine as a contributing factor in stuttering by demonstrating a reduction in stuttering under conditions in which a dopamine antagonist is present.
The Investigators
The study was proposed and is being conducted by Ms. Rebecca Glass, a high-school student involved in a three-year course called the “Science Research Program” (a.k.a. “Intel” or “Westinghouse” science program). In this program, Ms. Glass will develop, conduct, and present an original research project. Ms. Glass is a person who stutterers and has recognized changes in her fluency in association with regular exercise.
Ben C. Watson, Ph.D., CCC-SLP is Professor and Chair, Department of Speech-Language Pathology, New York Medical College, Valhalla, NY. Dr. Watson has conducted research into the physiology and neurophysiology of stuttering for the past 20 years.
References
Alm, P. (2004). Stuttering and the basal ganglia circuits: a critical review of possible relations. J Comm Dis, 37, 325-369.
Maguire, G., Gottschalk, L., Riley, G., Franklin, D. (2000). Risperidone in the treatment of stuttering. J Clin Psychopharm, 20, 479-482.
Goberman, A. & Blomgren, M. (2003). Parkinsonian speech dysfluencies: Effects of L-dopa related fluctuations. J Fluency Dis, 28(1), 55-70.
Wu, J, Maguire, G,m Riley, G., Lee, A., Keator, D, Tang, C., Fallon, J. & Najafi, A. (1997). Increased dopamine activity associated with stuttering. Neuroreport, 8, 767-770.
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