Statistics
Stuttering occurs for what percentage of people at what age?
Onset occurs for 55% of people at 25-36 months.
Multiple etiological factors that contribute to stuttering has lead to what proposal?
That there may be subtypes of stuttering: those who will persist in stuttering and those who will recovery naturally.
Define parsimonious.
Uses the least amount of ideas to explain the most facts
Name 3 stuttering like disfluencies (SLDs)
part word repetition, single syllable word repetition, and dysrhythmic phonation
5 primary risk factors for stuttering
gender, genetics, family hx, age of onset, stuttering that persists 7-12 months past p/o, disfluency length and
What is the percent of PWS that have a familial hx of stuttering? NFS?
PWS: 30-60%, NFS: <10%
Explain the diagnosogenic/semantogenic (Johnson, 1944) theory.
When a speaker tries to avoid normally disfluent speech events? Parents show concern and child struggles to avoid it?
When a stutter occurs on words previously stuttered it is called __________.
consistency
Name 3 typical disfluencies
phrase repetitions, interjections, tense pauses
Which of the following is the best example of a factor that may predispose a person to stutter?
gender
Prognosis for 4 year old 1 year past onset? 7 year old 5 years past onset?
recovery chance drops from 70% one year p/o to lower than 5% 5 years p/o
Explain the Cerebral Dominance Theory (Travis, 1931).
Neural signals from the 2 hemispheres reach the bilateral speech musculature in an asynchronous manner resulting in stuttering blocks.
asynchrony of neural impulses from both sides of the brain disrupts speech fluency.
Define Adaption, expectancy, adjacency.
stuttering declines w/each successive rereading of a passage
stuttering tends to occur on words the speaker predicts will be stuttered
if words are removed, stuttering tends to occur on words near those previously stuttered
3 dimensions of normal fluency
tension, timing, continuity
Describe one structural brain difference in PWS compared to NFS.
less dense white matter, more right hemisphere activity during speech, anomalous symmetry of planum temporale (adults)
Male to female ratio for children and adults?
Adults 4:1
DIVA: Directions into Velocities of Articulators
proposes stuttering is due to a disorder of sensorimotor speech control. PWS have unreliable feedforward systems so they rely excessively on controlling speech via feedback. Fluency is disrupted by the attempts to adjust speech movements after commands have been issued.
What is the difference between disfluency and dysfluency?
Disfluency: overt, momentary, disrupted speech events
Dysfluency: a complex disorder including speech, physiological, emotional, and cognitive factors lasting over time.
4 stuttering loci
content, long/multisyllabic words, beginning of a sentence, initial consonants
What's a psycholinguistic theory of stuttering.
Covert Repair hypotheses. Explain what it is.
What percentage of people in the world stutter? What are the incidence and prevalence rates?
Children 4%
Young adults .05%
Adults .03%
prevalence: 3.2%, incidence: 0.72%
Explain Operant Conditioning and Classical Conditioning
Operant: The consequence of a response can change the response frequency. Strengthening or weakening the voluntary behaviors through reinforcement. Pairing the stimulus to a behavior.
Classical: a neutral stimulus is paired with a naturally occurring stimulus to develop the same response.
Define expectancy.
stuttering tends to occur on words the speaker predicts will be stuttered
5 criteria for natural recovery
age, fewer than 3 disfluencies per 100 syllables, no stuttering for 4 years, rating of <1 by clinician and parent
Stuttering is caused by defective auditory feedback. The speaker expects to hear the sound earlier than their auditory system feeds it back.