Week Two

Question 1

Why is having stuttering theories important?

Answer 1

• Provides information for families and PWS
• Drive treatments
• Improve treatments

Question 2

What are some challenges to stuttering research?

Answer 2

• Difficult to observe onset
• Characteristics change with age
• Inconsistent occurrence
• Ethical limitations (wait to start treatment?)

Question 3

What are some early theories of stuttering?

Answer 3

Demosthenes
- speaking with pebbles in the mouth

Francis Bacon
- Tongue stiff and frozen and should be thawed with hot wine

Johann Friedrich Dieffenbach
- Stuttering due to the tongue ‘clave to the roof of the mouth”. treated by cutting out a wedge of the back of the tongue

Question 4

What are the subcategories of psychoemotional stuttering theories?

Answer 4

• Psychoanalytic theories
• Temperamental & emotional processes

Question 5

Describe the psychoanalytic theory?

Answer 5

• Psychoanalytic theories are now disproven
• contributed to the belief that stutterers are neurotic and the parents had a hand in causing stuttering
• Implication that even today many stutterers are referred to councillors/psychologists/are given anxiety medication

Question 6

Describe the temperamental and emotional processes related to psychoemotional theories of stuttering?

Answer 6

• CWS may have increased reactivity and decreased regulation
• However, temperament is genetically influenced and therefore stuttering is probably not solely able to account for these differences
• Emotional reactions may develop due to stuttering

Question 7

What are the subcategories that fall under psychobehavioural theories?

Answer 7

• Diagnosogenic theory
• Approach-avoidance conflict theory

-Two-factor theory

Psychobehavioural theories are based on the idea that stuttering is a behavioural response that develops in response to some form of reinforcement

Question 8

What is the diagnosogenic theory?

Answer 8

• This theory has now been disproven
• This theory argues that stuttering is caused by parents making a “big deal” out of a typical disfluency their child has

-This reaction is then what causes stuttering

• Disproven as disfluencies in CWS differ from those in children who do not stutter

Question 9

What is the approach-avoidance conflict theory?

Answer 9

• Psycobehavioural theory
• Stuttering is caused by a conflict between approach (drive to speak) and avoidance (fear of speaking)

Question 10

What is the two-factor theory?

Answer 10

• Psychobehavioural theory
• Core stuttering behaviours result from classical conditioning (anxiety to speaking situations)
• Secondary behaviours reinforced by operant conditioning (successfully prevent of end stuttering moment)

Question 11

What are some key points relating to psychobehavioural theories?

Answer 11

• They assume that anyone can acquire stuttering under the correct circumstances (this is incorrect)
• Concerned with observable phenomena
• Offer explanations for individual moments of stuttering rather than initial onset
• Cannot account for findings from genetic studies

Question 12

What are the subcategories under psycholinguistic theories?

Answer 12

• Covert repair hypothesis
• EXPLAN theory

Question 13

What is the covert repair hypothesis?

Answer 13

• Psycholinguistic theory
• stuttering results from self-monitoring of inner speech

Question 14

What is the EXPLAN theory?

Answer 14

• Psycholinguistic theory
• Execution of linguistic plan cannot be take place until its plan has been completed
• Asynchrony occurs if motor execution rate exceeds linguistic planning capacity

Question 15

What are some key points regarding psycholinguistic theories?

Answer 15

• Helps to account for various loci of stuttering and relationship between stuttering and language
• Doesn’t offer explanations of stuttering aetiology, onset or social emotional aspects

Question 16

True/false: psychoemotional, psychobehavioural and psycholinguistic can all contribute to stuttering?

Answer 16

• True
• Clinical management : reduce anxiety, identify stimulus cues that trigger stuttering, slow down speech

Question 17

What are the subcategories under biological theories?

Answer 17

• Genetic perspectives
• Neurological perspectives

Question 18

Describe the genetic perspective of stuttering

Answer 18

• A biological theory
• genes may be passed down that are linked to a predisposition of stuttering and genes that prevent natural recovery from stuttering
• Familial stuttering occurs in 30-60% of PWS but only in 10% of FS
• Estimate of 42-84% heritability of stuttering
• Genes alone do not explain stuttering
• having biological parents who stutter is more important than being raised by a parent with stuttering history

Question 19

Describe the neurological perspective of stuttering

Answer 19

• Biological theory of stuttering
• Evidence to suggest there are brain structure differences between PWS and FS, brain activation differences, and other neurological differences
• Reduced stuttering following Tx associated with changes in brain activity

Question 20

What is cerebral dominance theory?

Answer 20

• Biological/neurological perspective
• Theory that PWS have speech centred in both brain hemispheres, not just the left
• Stuttering results from a lack of cerebral dominance for speech production
• 2 sides of the brain “competing” leads to breakdown in speech
• Treatment: restore L-handedness

Question 21

IMPORTANT TO REVIEW

Answer 21

• aberrant sensory motor integration for speech production
• aberrant timing and sequencing of speech sounds
• compensatory/ maladaptive role of right hemisphere homologues

Question 22

What are the subcategories within multifactorial models?

Answer 22

• Demand and capacities model
• The multifactorial dynamic pathways theory

Question 23

Describe the demands and capacities model

Answer 23

• Multifactorial model
• attempted speech performance exceeds capacities for fluent speech
• no deficit implied

-failed balance between demands and capacities

Demands:
- Internal: complex thoughts to be expressed in complex linguistic forms
- External: environmental expectations and reactions to linguistic attempts

Capacties:
- Cognitive delevlopment
- Linguistic development
- Speech motor abilities
- Emotional maturity

Question 24

Describe multifactorial dynamic pathways theory

Answer 24

• Multifactorial model
• no core factor necessary for stuttering to emerge or persist
• Stuttering is a complex disorder resulting from interaction between various risk factors
• Variables may be internal or external and can interact in different ways in different children
• One small change in 1 factor may result in onset, development or persistence

Question 25

Describe the 1st neurological difference in the brains of PWS

Answer 25

Aberrant sensory-motor integration for speech production

• Studies show that PWS have decreased white matter integrity along parts of the left arcuate/superior longitudinal fasciculus.
• The left arcuate/superior longitudinal fasciculus is a pathway that connects the speech motor and auditory areas to enable mapping between speech sounds and motor plans. Therefore, the differences in this area may result in difficulty integrating auditory feedback into the speech motor programme
• There is also evidence to suggest aberrant activity in the primary motor cortex of PWS. For example, activity in the speech motor execution area preceded that of activity in the speech planning area. This is opposite to fluent speakers
• There has also been evidence to suggest the deactivation of left auditory cortices during speech tasks in people who stutter.

Question 26

Describe the 2nd neurological difference in the brains of PWS

Answer 26

Aberrant timing and sequencing of speech sounds

• Speech requires a very precise and complex coordination of movement.
• Changes such as rate, intonation prosody and rhythm must be made
• There is evidence to suggest that there is a problem within the interactions between cortical and subcortical structures responsible for the coordination and timing of movement
• The Basal ganglia-thalamo-cortical motor circuit (BGTC loop) provides lots of information from various parts of the brain and is crucial in the selection and initiation of movement sequences.
• In stuttering speakers this BGTC loop is impaired and results in difficulty initiating speech
• There is also evidence to suggest areas such as the putamen and supplementary motor area which support internal timing have impaired connectivity.
• Impaired basal ganglia circuits may result in influence from the cerebellum and another compensatory network.
• May be why external pacing systems, such as metronomes and chorus reading, help produce fluency in PWS as it compensates for the different internal timing abilities

Question 27

Describe the 3rd neurological difference in the brains of PWS

Answer 27

Compensatory and/or maladaptive role of the right hemisphere homologues

• Whilst studies have shown PWS have less volume/thickness and white matter integrity in the left hemisphere, they also have a larger volume/thickness in the right hemisphere.
• There are conflicting opinions as to whether an increase in thickness/volume of the right hemisphere is adaptive or maladaptive.
• There is a suggestion that a deficit in the left hemisphere feedforward control system results in an over reliance on right hemisphere feedback control mechanisms. This reliance on the right hemisphere results in the increased volume/thickness.