Etiology• Theories

– 1. Organic, Constitutional, or Medical– 2. Neurotic– 3. Behavioral or Learned

. Organic, Constitutional, or Medical

• Theories– 1. Cerebral Dominance– 2. Biochemical– 2. Laryngeal Dynamics– 3. Heredity– 4. Middle Ear Dysfunction– 5. Neurological Functioning

1. Theory of Cerebral Dominance

• Theories: Orton and Travis

• Fact: more stutterers are left handed

• Supporting Research– Moscovitch (1973) asserts that the right hemisphere in right-

handed people maintains some limited underlying ‘verbal competence’

– Geschwind limit of this verbal competence ‘depends on the degree to which the dominant hemisphere can control the verbal behavior of the minor hemisphere via midline commissures and other pathways”

• Tenant:– defective ‘motor lead control’ or incomplete cerebral

dominance• remediation: change handedness

2. Laryngeal Dynamics’ Theory

• Theorist: Adams

• Stutterers have longer VOT, SIT (speech initiation times) VIT (voice initiation times)

• describes characteristics – does not identify causal components of

disorder,

3. Biochemical

• Theorist: West

• Compared to a mild form of epilepsy

• term: dsyphemia

• Current Research: Dopamine

• Questions?

• Cause or effect

6. Middle Ear Dysfunction

• Theorist: Webster

• Non-synchronized middle ear muscle firing which means there are non-synchronized messages to the brain

4. Heredity Model Theory

• Theorists: Kidd, Goldberg, Wepman

• Facts: stuttering runs in families, 8-15%– 65-70% had stuttering relatives– twinning studies

• more stuttering in monozygotic twins, risk 77%

• Stuttering is determined by many factors, the factors are both hereditary and environmental and it affects the sexes differently– related to a THRESHOLD MODEL

5. Neurological Functioning

• Theorist: Perkins

• use of Positron Emission Tomography (PET) scans

• there is a neurophysical difference at the moment of stuttering

• Current research: role of Prefrontal Cortex

• Function:

• Question: cause or effect?

III. Learning Theories

• 1. Diagnosogenic

• 2. Two-Factor

• 3. Approach-Avoidance

• 4 Capacities/Demands

• 5. Anticipatory/Struggle

1. Diagnosogenic Theory

• Wendell Johnson, 1940’s• Tenants:

– a diagnosogenic disorder is one that is caused by its diagnosis

• person’s behavior is labeled as ______ and _____

– dysfluency in the ‘ear of the beholder’– listener (PARENT) reinforced s=through negative

reinforcement which parent believes in punishment

Diagnosogenic Theory continued

• 3 Behaviors that must occur– 1. Child repeats or hesitates while speaking

• frequency is not a critical variable

– 2.listener ‘diagnoses’ repetitions as abnormal and react accordingly

• “stop and start over

• thinking for what you are saying before you say it

• take a deep breath before you start

• talk more slowly

• non-verbal response such as looking away

– 3. Child becomes concerned and tries not to be dysfluent• attends more to the dysfluencies than previosly and becomes

upset when they occur

2. Two Factor Theory

• Theorist: Brutten and Shoemaker

• Stuttering results from the interaction of genetic and environmental factors

• Factor I behaviors result from emotional learning– classically conditioned– modified either though reconditioning or

counterconditioning– reconditioning involved returning a conditioned stimulus

to its previous neutral status• repeated presentations of the conditioned stimulus without

negative consequences

• ex: salesperson

Factor I Classical Conditioning Cont.

– counterconditioning-learning new responses to a conditioned stimulus

• repeated presentation of the conditioned stimulus in various negative emotion producing situations in a hierarchy

Two Factor Theory: Factor II

• Factor II behaviors learned through operant conditioning– instrumental responses operantly conditioned over

the years– developed in an attempt to prevent or reduce the

severity of stuttering– secondary behaviors– reduced through reinforcement, nonreinforcement

or punishment• reinforcement of fluency enhancing behaviors results in

elimination

3. Approach-Avoidance Theory• Sheehan

• Tenant– conflict arises in which the motivational drives

subserving both approach and avoidance are simultaneously aroused

– when the APPROACH drive is dominant, fluent speech

– when there is Avoidance BUT the speaker speaks, then…..

– Origins in learned speech anxieties and/or unconscious personally factors

4. Capacities/Demands Theory

• Starkweather

• Tenants– capacities for fluent speech-motoric,cognitive,

linguistic skills that make speech easy for most children-interact with demands for fluency placed on child by the external communicative environment and by child himself

• as capacity for fluency grows, expectations of parent and child also increase

• capacities and demands are increasing as a function of age

5. Anticipatory Struggle Hypothesis

• Bloodstein

• Tenants:

• disorder maintained by anticipating stuttering and then struggling to avoid it

III Neurotic Theory

• 1. Glauber

• 2. Bloom

• 3. Frustration Theory

Neurotic Theory Concepts

• Stuttering as a type of neurosis

• stutter because they attempt to cope with some type of repressed (unconscious) neurotic need in a way that allows them to be dysfluent

• hypotheses look upon stuttering as being both a symptom of an unsatisfied repressed emotional need AND purposeful behavior

1. Neurotic Theory: Glauber

• Stuttering behaviors -symbolic of the repressed need

• Repressed need for:– infantile need for oral erotic gratification– infantile need for anal erotic gratification

• stuttering represents anal movements “displaced upwards”

2. Neurotic Theory: Bloom

• Aggressive expression of hostile feelings person is afraid to express openly– stutterer makes those with whom he/she speaks

uncomfortable• assumes stuttering is ‘painful’ for the listener

Neurotic Theory Thoughts

• For many stutterers, stuttering is non-symptomatic– does not cluster with other problems

• Neither stutterers or their parents show no greater evidence of neurotic symptoms than the population

Etiology Questions

• What is Peters and Guitars’ theory of causality

• What is yours?

• Which one/s have you discounted

• What is “the point” of so many causation theories?

End of Lecture Notes

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