Interactions between Language and Stuttering

Interactions between
Language and Stuttering
J. Scott Yaruss, Ph.D., CCC-SLP
University of Pittsburgh
NU/SFA Workshop
for Fluency Specialists
July, 1996
Purpose
• To examine aspects of language
development that may be involved in the
onset, development, and maintenance of
fluency disorders
• To discuss the relationships between
language development and the
diagnosis and treatment of stuttering
Interactive Relationship
Between Clinical
Research and Clinical
Practice
?
?
What causes
Stuttering?
?
?
Factors That May Be
Involved in Stuttering
Genetic
Linguistic
Environmental
Motoric
Psychological
?
?
What does Language have
to do with Stuttering?
?
?
Language factors and stuttering
• Situational Factors
– Certain linguistic factors affect the
likelihood that stuttering will occur on a
given word or utterance
• Developmental Factors
– Certain aspects of language development
affect the likelihood that stuttering may
develop in an individual
Word-Based
Factors
• Length
boy
dog
mother
bicycle
• Familiarity
• Phonetic Stress
• Initial Sound
• Position in Utterance
• Meaning / Propositionality
• Phonetic / Phonological Complexity (?)
Utterance-Based
Factors
The boy ran
to his mother
with his dog.
• Length
• Grammatical
Complexity
• Pragmatic Intent
• Meaning / Propositionality
• Speaking Rate (?)
?
?
What do these situational
language factors have to
do with stuttering
treatment?
?
?
What we already know about
language and stuttering helps us
plan evaluation and treatment
• Determining appropriate level for
activities (hierarchies of treatment)
• Identifying speaking contexts or
situations that facilitate speech
fluency or exacerbate stuttering
?
?
How does language
development affect
stuttering?
?
?
Language Systems
Approach
• Pragmatics:
meaning of utterances
• Semantics:
meaning of words
• Syntax:
structure of utterances
• Morphology: structure of words
• Phonology:
sounds of words
Language Model
Approach
• Identify steps involved in language
processing and production
• Identify factors that might lead to
disruptions in formulating language
• Develop ways to treat these disruptions in
language processing to improve speech
Basic Steps in
Language Formulation
– Figuring out what you want to say
• Basic message
• Pragmatic intent
– Figuring out how you want to say it
•
•
•
•
Grammatical structure
Specific words
Sounds in the words
Prosody
Levelt’s (1989) “Blueprint for the Speaker”
CONCEPTUALIZER
discourse model,
situation knowledge,
encyclopedia
etc.
message
generation
monitoring
parsed speech
preverbal message
FORMULATOR
grammatical
encoding
surface
structure
LEXICON
SPEECHCOMPREHENSION
SYSTEM
lemmas
forms
phonological
encoding
phonetic plan
(internal speech)
phonetic string
ARTICULATOR
AUDITION
overt speech
Recent Models of Stuttering
and Language
• Recent theoretical models emphasize
language processing skills
• Covert Repair Hypothesis
(Postma & Kolk, 1993)
• Temporal Dyssynchrony
(Perkins, Kent, & Curlee, 1991)
• Sentence Plan Alignment (Karniol, 1995)
The Covert Repair Hypothesis (CRH)
• Attempts to explain speech disfluencies
produced by speakers who do and do not
stutter in context of general language model
• Theoretical Background
– Levelt’s (1989) Blueprint for the speaker
– Dell’s (1986, 1988) Spreading-Activation
Phonological and Lexical Encoding
Connectionist Models
TACTIC FRAMES
LEXICAL NETWORK
SYNTACTIC LEVEL
S
NP
VP
det
THE
CAT
JUMP
Det
N
V
V
N
Past
Plural
pl. V past
N
MORPHOLOGICAL LEVEL
WORD
S det
WORD
WORD
Stem
SN
Stem
Af
1
S
V
Af
THE
CAT
-S
Sdet
SN
Af 1
JUMP
–ED
S
Af 2
V
2
PHONOLOGICAL LEVEL
SYL
On
Rime
Nu
Co
k
æ
t
s
On
Nu
Co
Co
Spreading-Activation and
Phonological Errors
Morphological
Level
cap
cat
Direction of
Spreading Activation
downward
upward
Phonological
Level
k
æ
t
p
The CRH and Stuttering
• Explanation: Speech disfluencies occur when
speakers interrupt ongoing speech to repair
errors in their phonetic plan that are detected by
their internal speech monitors
• Assumption: Individuals who stutter have a
problem with their phonological encoding
mechanism that leads to frequent phonetic plan
errors that must be repaired
Delayed Phonological Encoding
T U = T ar get Un it
CU = Com petin g Un it
H igh
TU
CU
Activation
L evel
N or m al Activation
T U > CU
L ow
0
tim e
T im e of Selection
H igh
TU
CU
Activation
L evel
D elayed Activation
T U  CU
L ow
0
tim e
T im e of Selection
CRH Summary
• Speakers have the ability to monitor their speech -- both
before and after it is produced
• Speakers sometimes make errors in phonological
encoding due to the spreading-activation mechanism
• If speakers detect these errors, they can interrupt speech
to repair them before they are produced
• The by-product of the interruption is a disfluency
• People who stutter produce more disfluencies
because their phonological encoding mechanism is
impaired, so there are more opportunities for repair
Temporal Dyssynchrony Model
(Perkins, Kent, & Curlee, 1991)
Product of processing
high in awareness
Processing procedures low in awareness
Stress, intonation, duration, and vocal quality
PP SYSTEM
WORKING
MEMORY
SYSTEM
COGNITIVE SYSTEM
Formulation of ideas
LANGUAGE SYSTEM
Symbol System
Symbolic Mapping
prosody
SEGMENTAL SYSTEM
Phonetic Specifications
INTEGRATOR SYSTEM
Segments
Segments integrated into syllables
SPEECH MOTOR CONTROL SYSTEM
Syllable Slots
Integration of paralinguistic
and
prosodic components
Segment
order
Words for
phonemic analysis
Awareness
paralinguistic
Vocal signal system
Feeling and intent mapping
Temporal Dyssynchrony Model
• Speech is the result of many concurrent
language and motoric processes
– If timing of language processing components
is not precise, a breakdown will occur
• Perkins also incorporates time pressure
– time pressure increases likelihood of the “loss
of control” feeling that defines stuttering
– without abnormal time pressure, speech
disfluencies may occur, but stuttering will not
?
?
What do these models
tell us about individual
people who stutter?
?
?
Not Much!
Still, language models give us
guidelines about what specific
aspects of language we should
examine in our diagnosis and
treatment of children who stutter
?
?
Do children who stutter
have language disorders
more often than children
who do not stutter?
?
?
Stuttering and Language Disorders
• Nippold (1990) found no evidence that children
who stutter have more language disorders than
children who do not stutter
• Still, there may be some language disorders that
may contribute to the development of a stuttering
problem
– Word-Finding Problems
– Phonological Disorders
D
L

Stuttering and
Phonological Disorders
• Stuttering and disordered phonology co-occur
– 30% to 40% of children who stutter also exhibit
problems with phonology (compared to 2% to 6% of
the general population)
• Stuttering and disordered phonology interact.
– There seem to be differences in the basic speech
behaviors of S+DP and S+NP children
– This interaction may affect diagnosis and treatment
of stuttering and disordered phonology
dog
Stuttering and WordFinding Problems
• Word-Finding difficulties may be a factor in as
many as 50% of the children evaluated at the
NU Speech Clinic (Gregory & Hill, 1993)
• Possible Explanation:
– Difficulties retrieving words can lead to delays in
speech production or errors in lexical access
– Delays lead to breakdowns in temporal sequencing
of speech production (similar to Perkins model or
CRH)
Relationships between Stuttering
and Language Disorders
• The precise relationship is not known
– Disordered phonology or word-finding problems
do not cause stuttering
• many children who stutter exhibit normal phonology or
difficulties with word-finding abilities
• furthermore, there is no one cause of stuttering
– Disordered phonology or word-finding problems
may exacerbate stuttering
• associated difficulties with intelligibility might increase
children’s sensitivity to speaking
Relationships between Stuttering
and Language Development
• Although children who stutter may not exhibit
language disorders, they may exhibit subtle
difficulties with language development that might
contribute to the onset, development, or
maintenance of stuttering
• Therefore, it is important to thoroughly examine
children’s language skills when evaluating
children who stutter
Levelt’s (1989) “Blueprint for the Speaker”
CONCEPTUALIZER
discourse model,
situation knowledge,
encyclopedia
etc.
message
generation
monitoring
parsed speech
preverbal message
FORMULATOR
grammatical
encoding
surface
structure
LEXICON
SPEECHCOMPREHENSION
SYSTEM
lemmas
forms
phonological
encoding
phonetic plan
(internal speech)
phonetic string
ARTICULATOR
AUDITION
overt speech
CONCEPTUALIZER
message
generation
monitoring
Conceptualization
• Basic Message
– Does client stutter more on complex messages?
– Does client stutter more on utterances with greater
propositionality or meaning?
• Pragmatic Intent
– How does social interaction affect fluency?
– Does client stutter more when experiencing
greater demands on pragmatic or social
interaction skills?
FORMULATOR
grammatical
encoding
surface
structure
phonological
encoding
Formulation
Grammatical Encoding
• Does client stutter more in situations which
require more complex utterances?
• Does client stutter more on syntactically
complex utterances?
• Does client demonstrate problems with
syntactic development which might interfere
with fluent speech production?
FORMULATOR
grammatical
encoding
LEXICON
lemmas
forms
phonological
encoding
Formulation
Lexical Access
• Does client exhibit word finding problems that
might interfere with speech production?
• Does client exhibit frequent mislabelings or
nonsystematic speech errors which might
interfere with fluent speech production?
• Are some words harder to retrieve than others?
FORMULATOR
grammatical
encoding
surface
structure
Formulation
Phonological Encoding
phonological
encoding
• Does client frequently produce nonsystematic
speech errors which might lead to production
self-repairs or speech disfluencies?
• Does client have difficulty retrieving the
phonological form of utterances (as in the “tip of
the tongue” phenomenon)?
FORMULATOR
phonological
encoding
phonetic plan
(internal speech)
Formulation
Phonological Development
ARTICULATOR
• Does client exhibit phonological delay which
might indicate a slow-to-develop linguistic
formulation system?
• Does client exhibit phonological delay which
makes communication more difficult and
increases sensitivity about his/her speech?
Articulation
(a hint of motor involvement)
• Does child stutter more when using a faster speaking
rate?
• Does child stutter more when leaving less time for
linguistic planning and formulation of utterances?
• Does child have difficulties with diadochokinetic (DDK)
abilities that might interfere with ability to rapidly and
precisely produce speech
?
?
So what does all this mean
for stuttering treatment?
?
?
Treating Stuttering in the Context
of Language Development
• Understanding how a child’s language development
(or language disorder) affects stuttering should help us
plan treatment
• If a child demonstrates both a language disorder and
stuttering, we should treat both disorders
simultaneously by combining the methods of language
stimulation with fluency facilitation
Combining Therapy for
Disordered Phonology
and Stuttering
ring
 Incorporate target sounds for remediating the
phonological disorder into fluency activities
– Model target sounds while modeling ERS
(e.g., read a short story loaded with /r/ words)
– Play “go fish” while emphasizing ERS or Easier
Beginnings and good turn-taking skills. Use words
with target sound and minimal pair sound to
emphasize contrasts
Summary
• An increased understanding of the relationship between
language and stuttering can help us diagnose and treat
individuals who stutter
• Language processing models currently being developed
should help us better understand one of the factors
which may be associated with the onset, development,
or maintenance of stuttering
• Such models can help us identify aspects of speech and
language production that should be considered when
evaluating an individual who stutters.

Download Report