Lectures 1 - 6 Flashcards
Operational/symptomatic definition
Can be measured/counted
Used to diagnose
Used in research
Disruption in the fluency of verbal expression, characterised by INVOLUNTARY, audible OR silent repetitions or prolongations in utterances
Stuttering stages (What is affected first?)
- Whole word repetitions
- Syllable/part-word repetitions
- “Dragging stutter” - prolongations
- Blocking - silent repetitions
When does stuttering onset?
ALWAYS in childhood
Where in the word does stuttering occur?
Stuttering almost always occurs at the beginning of words
Internal/private definitions of stuttering
Definitions that focus on the internal/psychological components of stuttering
Used in clinic
“Temporary or covert loss of control of the ability to move forward in speech
Consensus definition
Whatever is perceived as stuttering by a reliable observer, who has relative agreement with others
- Important to consult colleagues before beginning expensive and time-consuming treatment
- Most reliable observer = patient/patient’s parents
Janet’s definition
Stuttering is a tendency in the speech motor system to destabilise more easily than another child. This tendency has a genetic basis, and can become highly emotional
Observable features of stuttering
Whole word repetition Repetitions of initial sounds and part words Prolongations Blocks Non-verbal: facial and body movements - jaw jerking, eye closure, shaking
What is the clinical importance of non-verbal features?
The level of intensity of non-verbal features can be indicative of a patient’s prognosis, or their attitude towards their stutter
Unobservable features of stuttering
Negative emotions - self confidence - anxiety Word avoidance Word revision
Epidemiology
Rates of diseases in populations, which considers how these rates are affected by variables such as age, gender, social class
Importance of understanding stuttering epidemiology
Drives every clinical decision
Makes you accountable for taking on and treating clients - by knowing prognosis, what has been effective treatment in the past
Allows you to consider the need for treatment (given that you are using tax payers’ money)
Crucial for counseling caregivers/clients (sound knowledge of the nature of stuttering, prognosis, recovery rate etc.
What is the INCIDENCE of stuttering? (How many people will develop stuttering at some point in their lives?)
4-5% of the population (which is quite high- the same as epilepsy)
What is the PREVALENCE of stuttering? (What percentage of the population has a stutter at any given time?)
1% of the population
Therefore there are 27,000 people in WA at this time that stutter
What is the gender ratio of stutterers?
4: 1 ratio of males to females
- Boys have a slower myelinisation in early childhood, and are more prone to other speech and language disorders
The issues with “spontaneous recovery”?
- Stuttering wasn’t defined properly
- Measures weren’t frequent or rigorous enough to be valid
- Can’t test spontaneous recovery anymore - ethical issues
- Perhaps no such thing as “spontaneous recovery” - parents are ACTIVE CHANGE AGENTS
What is the usual age of onset for stuttering?
Between 2;6-3;6
- At this age, children start to use more complex prosody, which places a greater demand on speech resources
- E.g. “daddy gone” becomes “where’s my daddy gone mummy?” (phrased as question)
- Approximately 1% of children have a speech motor system that will destabilise more easily with the demands of frequency, formants etc.
Factors that modify stuttering?
Mr Smith Always Marks Damn Rough
Measurement Reactivity Situational Reactivity Adaptation Effect Modified Vocalisation Hypothesis Discriminative Stimuli Response Contingent Stimulation
Measurement Reactivity
If the client suspects that their speech is being measured/analysed, then you won’t get a truly representative sample (especially if voice recording device is present)
- Very important in setting goals, discharge criteria - you are RESPONSIBLE TO THE CLIENT
- Measurement reactivity influences the speech samples you get, which in turn influences the type of therapy you give
- Sample could either be artificially fluent or more stuttered
Situational Reactivity
Certain situations can be the most taxing for particular clients
- Job interviews
- Public speaking
- Talking over the phone
Adaptation Effect
Practice effects - e.g. if you ask an adult to read the same passage twice, there will be a decrease in the occurrence of stuttering - therefore DONT use the same passage to assess the client’s speech each week
Modified Vocalisation Hypothesis
If you use your speech system differently, you can temporarily reduce your stutter - because they change the way the laryngeal system operates
- Chorus reading (reading along with the clinician)
- Speaking with an accent
- Singing
- Whispering
- White noise masking/DAF (when adults can’t hear their own voice, they are perfectly fluent
Issues with white noise masking
- The white noise needs to be at a level of 90dB which is loud enough for noise-induced hearing loss
- Most adults who stutter are blocking - which precludes the use of these white noise devices because they require voicing for initiation
Advantages of data measurement
Contributes to ACCOUNTABILITY
Record the severity and extent of the client’s problem
Allows prescription of appropriate goals and duration of treatment
Every session is started by gathering baseline data - need to have a representative sample to show CHANGE
Within clinic measurement situations for children
Sharing a book, playing with toys, arts and craft, cooking
Beyond clinic measurement situations for children
In free play, at meal times, in the bath - need to measure in a space/time that child is relaxed and confined
Within clinic measurement situations for adults
Confrontational naming - picture description, reading passages, making a telephone call, ask their name and address (can’t avoid words)
COVERT measurements - assessing their speech without their knowledge. E.g. set up a marketing call, ask their spouse to record them when they don’t know (given Measurement Reactivity)
Response Contingent Stimulation
The feedback you provide depends on the client’s response and level of success
- If the client responds fluently, then give positive feedback
- If the client stutters, clinician/parent should STOP the child, e.g. “careful darling”
- This is to stop the NEUROLOGICAL MAPPING - i.e. stop the behaviour, not the child (don’t stop them from talking all together)
What is the most important measure of stuttering? What kind of measure is it?
%SS - Molecular measure (objective)
What is the normal/stuttered %SS?
Normal dysfluencies = 0-2%
Mild dysfluencies = 2-5%
Moderate = 5-10%
Severe = >10%
What is the usefulness of SPM?
SPM = syllables per minute
- Rate control = important part of fluency therapy
- Consider ALONGSIDE %SS
- If 25% of syllables are stuttered, and only 120 syllables are produced each minute, the client is likely to be blocking (the stutter takes up a greater amount of TIME than someone who scores 25%SS on an SPM of 180-200
SMST
stutters per minute of speech time
- need to ensure that the clinician and parent are scoring the same
Mean number of repetitions
Sometimes there is a qualitative shift in the nature of the stutter
- e.g. at the beginning of therapy, client may have produced 6-8 repetitions on each word to 2-3 repetitions
Molar Measures
Perceptual internal threshold judgements
- subjective
- doesn’t involve counting speech events
- Uses rating scales
- Parent fills out graph/chart each day with SEVERITY RATING - gives clinician idea of how child copes with being tired/sick/on the weekend
OASES
- The severity of the stutter does NOT necessarily determine the ATTITUDE towards the stutter
- Interested in internal/emotional dimensions of stuttering
What is concordance and discordance?
CONCORDANCE: The occurrence of stuttering in both members of a pair of twins
DISCORDANCE: When only one twin has a stutter
Concordance occurs more in monozygotic twins
Genetics vs Environmental Factors
Stuttering is a combination of genetic and environmental factors.
Genetics = 70%, Environmental = 30%
Concordance is not 100% - showing environmental factors
Adoption studies show that stuttering was more closely related to whether or not a child’s BIOLOGICAL parents (rather than adoptive parents) stuttered - genetic factors
Stuttering as a complex trait
Stuttering is the result of complex genetic traits
A possible mutation in the major gene is reflected in the phenotype ONLY when certain environmental and other polygenetic factors are present
Sex-Linked studies (gender ratios)
- A mother who studies is more likely to pass it on to her SONS than her daughters (67% compared to 19%)
- Girls need a higher ‘dosage’ of the genetic component of the vulnerability to stutter for the stutter to be realised
Which chromosome?
Some researchers found chromosome 18 to be a strong marker - chromosome 18 is known to be associated with speech production in the brain
Other studies have shown links to chromosomes 9 and 12
This leads authors to suggest that stuttering can be caused by mutations at MANY different loci
How do we know that stuttering is not a single-gene disorder?
Because NOT ALL children in the family will stutter
Sib ship rankings
Many parents worry about mimicry - don’t want their child around other children who stutter
HOWEVER if there was an element of mimicry, then everyone younger than the proband would stutter - research shows that the position of a child who stuttered (in the family) was completely RANDOM
Kids don’t adopt habits that make life harder for them
Clinical implications for genetic basis of stuttering
- Inform parents that stuttering is a family disorder
- Doesn’t require genetic counselling - because the child may not even develop the stutter (and if they do, then it can be treated)
- Environmental influences can play a part in assisting recovery and help facilitate fluency
- Emphasise the effectiveness of treatment in childhood if the stutter is identified EARLY
What are the three types of aetiological theories of stuttering?
Psychogenic theories
Learning theories
Organicity theories
What is a psychogenic theory?
Stuttering is the result of an abnormal personality or underling emotional and psychological issues - research “found” that children who stuttered were anxious and parents were overprotective - but these traits are likely to be the RESULT of the stutter - not the other way around
Recent studies found NO LINK between personality and stuttering severity
Learning theory
Stuttering is a LEARNED behaviour from their parents’ NEGATIVE REACTIONS to normal childhood dysfluencies
- If you pay attention to the stutter, then it will get worse
- treatment encouraged parents to ignore the stutter
Anticipatory Struggle Hypothesis (part of learning theory)
People stutter because of a learned BELIEF in the difficulty of speech and an ANTICIPATION of speech failure
- Child anticipates negative reactions from parents (facial expressions etc.) and blocks as a reaction
Issues with learning theories
- Not all children with stutters receive negative reactions from their parents
- Children who stutter FLUCTUATE
- There would not be such extreme gender imbalances if learning theories were true
Operant Learning Theory
Body has learnt that EVENTUALLY they will get the word out after their stutter (and therefore they associate the motor characteristics of stuttering with the eventual successful output of the word)
Demands and Capacities Hypothesis
Stuttering results when the demands of fluency from a child’s social environment exceed the child’s cognitive, linguistic, motor or emotional capacities for speech
- Doesn’t explain cause, but describes the fluctuation/impact of environmental factors
Organicity Theories
CECLMSS
Cerebral Dominance EEG Cybernetic Models of Stuttering Laryngeal Reaction Times Manual Reaction Times Stuttering as Prosodic Disorder Speech Motor Control Theory
Cerebral dominance
Nervous system of people who stuttered had not yet matured enough to achieve left hemisphere dominance of speech movements - by investigating the handedness of individuals who stutter
EEG studies
Researches used electroencephalography to compare the neural activity of stuttered v. non-stutterers
Abnormal alpha levels were detected during stuttering episode, and thought to cause stuttering
However the heightened motor responses, anxiety and effortful nature of the stuttering episode is likely to have caused the extra cortical activity - not the other way around
Cybernetic Models of Stuttering
Servosystem feedback mechanisms were thought to be defective. This distorted feedback creates the misconception that an error has occurred and the speaker attempts to correct it over and over again
Studied by altering the feedback (by delaying it) - DAF
People who stutter became fluent using DAF, and were weaned off the system by decreasing the delay
Laryngeal reaction times
Researchers found that people who stutter had a slower VOT
However, they weren’t born with anything different - studies show that children with and without stutters had the same VOT
Larynx develops a difference over time, as the result of the physical patterns developed by people who stutter
Manual Reaction Times
There is no difference in the reaction times for button pressing and non speech vocalisation tasks
However, people with stutters had a slower VOT in speech tasks
Stuttering as a PROSODIC Disorder
Stuttering was more common on specific loci of information units in speech e.g. nouns, adjectives and personal pronouns - all of which are stressed in English (by altering the laryngeal function)
Speech Motor Control Theory
People who stutter have a neurophysical deficit that results in the inability to move their articulators as accurately or quickly as their non-stuttering counterparts
The V model
Suggests reasons why people tend to stutter on stressed syllables
Stressed syllables = changes to frequency, duration and amplitude. The period from stressed to unstressed syllables is thus a period of EXTREME VARIABILITY
Proposes that people who stutter have a lower threshold of variability and hence are more prone to destabilisation of the speech motor system
Syllable repetitions are seen as an attempt to get over the variability of syllable stress. Prolongations/blocks are attempts to get over repetitions
Effortful Control
Self regulatory trait representing voluntary and executive functions of temperament
- Children with higher levels of EC display regulation of behaviour and attention, and have LOWER stuttering severity ratings
- High EC means child has many more resources to focus on treatment
- High EC = temperament allows child to respond to their speech with compensatory behaviour, attention and emotion
- Children without high EC will be taxed more by changes in their environment (e.g. being sick, excited, tired, unhappy) resulting in more frequent breakdowns in their speech
Therapy implications for EC
Therapy should be focus don building skills related to EC (i.e. attention, inhibitory control and perceptual sensitivity, as well as negative emotions, self-perception etc.)
