Theories about stuttering

1. Theories about stuttering Constitutional-based theories Developmental-environmental-based theories Integrated theories

2. Constitutional-based • Brain-organization • Timing disorder • Internal monitoring disorder • Language production disorder • Physiological tremor disorder

3. Brain organization • Orton-Travis theory (1920) • Lack of dominance: tx focused on changing handedness back to left-side • Geschwind-Galaburda theory (1985) • Delayed LH growth in fetal development caused RH dominance for language in unsuited hemisphere • Testosterone exposure during fetal development cause of delay • Webster theory (1993) • LH dominate for language but the supplementary motor area in this hemisphere is easily disrupted, and the RH overactivity is highly disruptive to SMA

4. Timing disorder • Kent (1994) • Adapted his theory from Van Riper’s • Deficit in temporal planning • Blamed temporal planning deficit on language localizing in RH • Thought regulation of emotions were partially responsible for deficits in timing

5. Internal modeling theories • Neilson and Neilson (1987) • Reduced Capacity for Internal Modeling • Sensory motor feedback system malfunctions gives “wrong” information creating disfluencies • Max, et al (2004) • Based on insufficient internal models of speech production that result in repetitions as the child tries to “reset” to match the internal feedback received

6. Language deficit • Kolk & Postma (1997) • Covert Repair theory • Deficits in the planning and assembling of language units result in disfluencies • Phonology plans are most commonly disrupted language unit • Perkins, Kent and Curlee (1991) • Dyssynchrony between paralinguistic components (RH) and linguistic components (LH)

7. Physiological tremor • Unstable neuromuscular system • Small tremors in speech muscles that rapid and rhythmic • Not present in all stutterers • Do not appear in young stutterers

8. Developmental/Environmental • Diagnosogenic theory • Anticipatory struggle theory • Capacities and demands theory

9. Diagnosogenic • Wendell Johnson (1930s) • “Stuttering is in the ear of the listener; not in the mouth of the child.” • Stuttering begins when it is diagnosed as “stuttering”

10. Anticipatory Struggle • Oliver Bloodstein (1987, 1997) • Early communication failures create frustration and struggle, which result in disfluencies • Acknowledged that other factors, such as living in a critical environment, perfectionistic parents, etc., combined with anticipatory struggle caused stuttering

11. Capacities and Demands • Andrews et al (1983) • Limited neurological capacity • Demands of the act of speech compete with other demands • Rapid language development • Cognitive skills • Fast talking parents, etc.

12. Integrated • Two stage model of stuttering • One model to explain the development of core behaviors (primary stuttering) • One model to explain the development of secondary behaviors (secondary stuttering)

13. Primary Stuttering • Caused by constitutional factors • Brain differences creating dyssynchrony of speech

14. Secondary Stuttering • Caused by constitutional factors • Temperament differences • Emotional effects on hemispheric activity

15. Study Questions • 1, 4, 6, 9, 10 from chapter 4 • 4, 6, 7, 8, 12 from chapter 5