Etiologies of Stuttering

1. Etiologies ofStuttering

2. Three Ps of Etiology • Predisposing factors • Precipitating factors • Perpetuating factors

3. Predisposing Factors • “What factors cause one person to be at greater risk than another for beginning to stutter?” (i.e., genetics) • “Nature vs. Nurture”

4. Precipitating Factors • Those agents thought to have made stuttering surface or those that brought it to its present state • Rapid growth in speech-language skills during the preschool years • Competition among siblings for attention and conversational turns • Social adjustments necessary when entering school settings

5. Identification and Interaction of Predisposing and Precipitating Factors • Factors are not static/rather are dynamic and changing • Do not always know the causal link between predisposing and precipitating factors and the occurrence of stuttering

6. Interactions Cont’d. • Child presents with a family history of stuttering (predisposing factor), stuttering began around the age of 3 years when his speech-language skills were growing rapidly, whose home routine was busy as both parents worked outside, and who was beginning preschool (precipitating factors)

7. Perpetuating Factors • variables that are continuing/maintaining stuttering • Certain environmental/physical factors may reinforce/perpetuate stuttering • Need to identify perpetuating factors • Criticism of speech • Inappropriate linguistic models • Unrealistic expectations • Experience of fluency failure • Negative feelings and attitudes • Vary with each individual • Simple or complex/ Subtle or obvious • Malleable or resistant to change

8. Stuttering as an Emotional or Psychological Problem • Neurotic Theories • Psychoanalytic explanations of stuttering held that stuttering satisfies oral or anal erotic needs or represents repressed hostility. • Stuttering is an attempt to suppress speech and is a symptom of a deep neurotic conflict.

9. Neurotic Theories Cont’d. • Flexible interpretation: • If the stutterer admits to, or is assessed as having personal problems, it is quickly assumed that his stuttering is a manifestation of these problems. • If the stutterer gives all appearance of being normal and well-adjusted, his “symptoms” (stuttering) can be interpreted as representing his “solution” to inner conflicts

10. Neurotic Theories Cont’d. • Clinical and research data do not provide strong support for the conclusion that stuttering is usually a symptom of a neurosis or other type of emotional disorder. • But they do not rule out the possibility that it is a symptom of such a disorder for some persons who stutter • Results of most studies indicate that stutterers are as well adjusted as their non-stuttering peers. • Stutterers are more similar to their non-stuttering peers than they are to persons who are known to be emotionally disturbed.

11. Factors contributing to Stutterers seeming less well adjusted • 1. Attitudes toward speaking • 2. less well adjusted as a consequence of living with stuttering. • 3. not as outgoing. • 4. avoid talking on the telephone. • 5. Unwilling to express anger openly when doing so would be appropriate • 6. may be depressed bc they’re trying to cope with stuttering. • 7. Self persecution: failure to overcome stuttering viewed as their fault • 8. They may over react to stuttering. • 9. They may feel guilty about stuttering. • 10. They may experience anxiety about speaking.

12. Characteristics of Stuttering and Non-stuttering Children • No significant difference in degree of • Dependency • Sensitivity • Shyness • Fears • Enuresis • Disturbing dreams • Ability to form relationships with peers • Mother-child relationships • Father-child relationships

13. Related Theories • Stuttering as communicative failure and anticipatory struggle behavior • Diagnosogenic theory-semantic theory-states that stuttering is caused by the parent’s or care giver’s misdiagnosis of and inappropriate reaction to normal disfluencies in a child’s speech, followed by the child’s attempts to avoid the disfluencies that are mistakenly assumed to render the child’s speech as abnormal.

14. Related Theories Cont’d. • The Continuity Hypothesis-proposed by Bloodstein-suggests that stuttering develops from normal disfluency that becomes tense and fragmented as the child experiences frustration and failure in attempts to talk. • Experiences that increase difficulty with speech • Criticism of normal disfluencies • Delay in speech-language development • Traumatic experience in oral reading • Cluttering • Reminders to “slow down”

15. Related Theories Cont’d. • Preparatory Set-Van Riper-stuttering emerges gradually from a child’s normal hesitations and repetitions. • Become chronic when the child begins to: • Anticipate, avoid and fear speech • Stuttering originates from environmental, organic, emotional sources

16. Stuttering as Learned Behavior • Stuttering as an avoidance response • Conflict theory of stuttering and avoidance reduction • Operant conditioning • Classical conditioning • Eclectic conditioning • Vicarious conditioning

17. Avoidance Reduction • Sheehan-viewed stuttering as resulting from a double approach-avoidance conflict between speaking and not speaking and between being silent and not being silent. • Stuttering is the result of “speech vs. silence”

18. Operant Conditioning • Speech is a behavior subject to operant control of positive and negative reinforcements and punishments. • Stuttering begins as “normal disfluencies” which are natural and understandable. • Initially, these disfluencies are reinforced through some schedule of positive reinforcement.

19. Operant Cont’d. • These conditions recur and become discriminative cues which control disfluencies • Positive reinforcement is replaced with punishment by the parent or significant someone when they begin to disapprove of the disfluencies. • The child develops negative emotions about speaking and begins to struggle with the nonfluencies

20. Classical Conditioning • Fluency failure explained by Brutten and Shoemaker • Stage 1-the speech features of stuttering are a “form of fluency failure” which is believed to be associated with a negative emotional state. (negative emotion causes initial fluency failure) • Stage 2-negative emotion and resulting fluency failure become linked to certain external stimuli through associative learning • Stage 3-there is an extension of the range of stimuli to which the negative emotional response becomes associated.

21. Classical Cont’d. • 1. Does not assume that the original stuttering behavior was normal. Original disfluent behaviors are not normal. • 2. Original fluency breaks consist of disorganized forms of previously integrated behaviors • 3. Antecedents of stuttering are considered to be as important as its consequences

22. Eclectic Conditioning • Any combination of learning theories can be operating for the individual simultaneously

23. Vicarious Conditioning • The behavior of the person becomes conditioned as that person watches someone else being conditioned.

24. Organic Theories • Referred to as “Breakdown Theories” characterize the moment of stuttering as an indication of failure or breakdown in the complex coordination required for speech.

25. Breakdown Theories Cont’d. • Dysphemia-the stutterer is believed to be inherently different from the non-stutterer. • Stuttering is the joint product of hereditary predisposition and precipitating factors in the environment • Shock • Fright • Illness • Injury

26. Organic Theories Cont’d. • Cerebral dominance theory-Travis-postulated that a conflict exists between the two halves of the cerebrum for control of the activity of the speech organs • Also known as handedness theory • 20’s and 30’s changed children’s handedness to correct stuttering

27. Cerebral Dominance Theory Cont’d. • Travis (1978) indicated “I have never disavowed the cerebral dominance theory as an explanation of the underlying basis of stuttering. I have; however, acknowledged publicly the futility of shifting handedness in its management.” • The conflict between the two hemispheres for the control of speech resulted in neuromotor disorganization and mistiming resulting in stuttering

28. Biochemical Theory • Adheres to the belief that the basic difference between stutterers and non-stutterers rests in metabolic factors and tissue chemistry. • West (1958)-concept of stuttering as a convulsive disorder related to epilepsy-called “pyknolepsy”

29. Perseveration Theory • Persons who stutter have an organic predisposition to motor and sensory perseveration of which stuttering is an outward manifestation. • Eisenson-stuttering is a transient disturbance in propositional language usage.

30. Stuttering –Brain Lesion • Stuttering involves changes in the interaction of laryngeal, supra-laryngeal, and respiratory reflexes • Implicates the brainstem as the site of lesion • Stuttering is the consequence of disruption of motor organization, timing, and control

31. Stuttering as a Result of Disturbed Feedback • Auditory function-questions regarding the basic integrity of the auditory system of stutterers have had a long history • Areas investigated • Dichotic listening-to determine hemispheric specialization for speech

32. Auditory Function Cont’d. • Acoustic reflex • Phase disparity • Central auditory function • All have been investigated to assess the effects of auditory feedback • Clinical results indicate that disruption in the auditory channel of a stutterer while speaking produces fluent speech

33. Cybernetic Theory • Closed-loop systems-behavior and physiological control interpret activity and learning as self-regulated processes rather than a series of stimulus-controlled reflexes or discrete stimulus-response units.

34. Closed loop systems cont’d. • Error sensitive, error measuring, self adjusting, goal-directed mechanisms which employ feedback of the output to the place of control

35. Feedback Model • Ear=the sensor • Vocal organs + motor innervations=the effectors • Brain=the control

36. Feedback Systems • Speech-When errors occur, the system corrects itself by searching for the appropriate output until it is achieved • Stuttering-The feedback system used to monitor speech has too much distortion, interference, and overload.

37. Demands and Capacities Model • Child’s capacity-Fluent speech characterized by continuous production, without effort at an appropriate rate • Demands-pressure imposed on the child by listeners and himself • When the demands exceed the child’s capacities for fluent speech stuttering occurs

38. Capacities • Capacities for fluent speech • 1. speech motor control-rate of syllable production and coordination of movement • 2. language formulation-word finding, formulation of grammatical sentences, and knowledge of conversational rules • 3. social-emotional maturation • 4. cognitive skill-general intelligence and metalinguistic skill

39. Demands • Those conditions that impose a pressure perceived by the child to speak at greater rate (i.e., faster) or with greater continuity (i.e., smoothness) • Demands increase with maturity and include time pressure, uncertainty, and avoidance

40. Linguistic Considerations • Research about linguistic aspects of stuttering and stutterers has contributed to concern over language development

41. Language-Stuttering Relationship • 1. Some stutterers acquire language more slowly • 2. Poorer auditory recall of linguistic information • 3. Higher number of grammatical errors • 4. Increased word length/increased stuttering • 5. Stuttering occurs more on words of importance • 6. Less stuttering with high word frequency • 7. Repeating prosodic patterns reduces amount of stuttering

42. Summary and Synthesis • Factors increasing risk or predisposition for stuttering: • Gender • Age (majority between 2 and 5 years) • Family history • Socioeconomic status and nationality- middle and upper-middle class families and certain groups from Canada, Korea, and West Africa show greater risk • Twins • Mental retardation • Brain injury • bilingualism

43. Group Differences between Stuttering/Non-stuttering children • Greater likelihood to have a history of delayed articulation or language development • Poorer performance on verbal and motor tests of intelligence • Poorer school performance • Less left-hemisphere dominance for speech • Slower reaction times • Poorer recognition and recall of competing messages • Slower speech movements even during fluent speech

44. References • Shapiro, D.A. Stuttering Intervention. Texas: Pro Ed., 1999 • Gregory, H. H. Stuttering Therapy: rationale and procedures. Boston: Pearson Education, 2003