stuttering

Fluency Disorder

A “SPEECH DISORDER” CHARACTERIZED BY DEVIATIONS IN CONTINUITY, SMOOTHNESS, RHYTHM, AND/OR EFFORT WITH WHICH PHONOLOGIC, LEXICAL, MORPHOLOGIC,AND/OR SYNTACTIC LANGUAGE UNITS ARE SPOKEN

Disfluency

REFERS TO INTERRUPTIONS OF SPEECH THAT MAY BE

NORMAL OR ABNORMAL

Stuttering

REFERS TO SPEECH EVENTS THAT CONTAIN MONOSYLLABIC WHOLE-WORD REPETITIONS, PART-WORD REPETITIONS, AUDIBLE SOUND PROLONGATIONS, OR SILENT FIXATIONS OR BLOCKAGES. THESE MAY OR MAY NOT BE ACCOMPANIED BY ACCESSORY (SECONDARY) BEHAVIORS (I.E., BEHAVIORS USED TO ESCAPE AND/OR AVOID THESE SPEECH EVENTS).

Typical Disfluency

An interruption of speech in a typically developing individual

Sex Ratio

3 BOYS FOR 1 GIRL FIRST GRADE

5 TO 1 IN 5TH GRADE/ADULTS

Can stuttering be cured?

IT OFTEN CURES ITSELF.

• ONCE STUTTERING HAS BECOME FIRMLY ESTABLISHED

AND THE CHILD HAS DEVELOPED MANY LEARNED

REACTIONS, A CONCERTED TREATMENT EFFORT IS

NEEDED.

Fluent Speech

• SMOOTH, CONTINUOUS, AND EFFORTLESS FLOW OF SPEECH.

• DISFLUENCIES OCCUR LESS THAN 10% OF THE TIME.

• REPETITIONS (IF PRESENT) ARE SLOW, EVEN, AND TYPICALLY

LIMITED TO ONE OR TWO PER INSTANCE.

• DISFLUENCIES ARE RELAXED, AND THE SPEAKER IS USUALLY

UNAWARE OF THEM.

• TYPES OF NORMAL DISFLUENCIES INCLUDE MULTISYLLABIC

WORD AND PHRASE REPETITIONS, REVISIONS, AND

INTERJECTIONS

Disfluent Speech

• FREQUENT INTERRUPTIONS IN SPEECH FLOW, SUCH AS PART-WORD

REPETITIONS, SINGLE-SYLLABLE WORD REPETITIONS, PROLONGATIONS,

AND BLOCKS.

• REPETITIONS MAY BE RAPID, ABRUPT, AND TENSE, OFTEN EXCEEDING

TWO PER INSTANCE.

• PROLONGATIONS (STRETCHING OUT SOUNDS) AND BLOCKS (INABILITY TO

INITIATE SOUND, SOMETIMES WITH VISIBLE STRUGGLE) ARE COMMON.

• DISFLUENCIES MAY BE ACCOMPANIED BY SECONDARY BEHAVIORS (E.G.,

EYE BLINKS, HEAD NODS) AND NEGATIVE FEELINGS (E.G., FRUSTRATION,

EMBARRASSMENT, FEAR), ESPECIALLY AS STUTTERING PROGRESSES

FROM BORDERLINE TO ADVANCED LEVELS35.

• THE SPEAKER IS OFTEN AWARE OF THEIR DISFLUENCY AND MAY REACT

WITH FRUSTRATION OR AVOIDANCE.

Core Behaviors

The basic speech beahviors of stuttering- repitions,prolongations and blocks

Atypical disfluencies

THREE OR MORE WITHIN-WORD DISFLUENCIES PER 100

WORDS

• DISFLUENCIES OCCUR ON MORE THAN 10% OF

SYLLABLES

• PREDOMINANT USE OF PROLONGATIONS, BLOCKS AND

PART-WORD REPETITIONS

• PRESENCE OF SECONDARY BEHAVIORS/INCREASED

TENSION

• VOWEL NEUTRALIZATION (SCHWA) DURING REPETITIONS

• DURATION OF SINGLE INSTANCE OF DISFLUENCY THAN

EXCEEDS 2 SECONDS

• UNCONTROLLED OR ABRUPT CHANGES IN PITCH

Secondary Behaviors

LEARNED REACTIONS TO THE CORE BEHAVIORS.

• PURPOSE IS TO ESCAPE OR AVOID THE

STUTTERING.

• CONCOMITANT OR ASSOCIATION BEHAVIOR

• EXAMPLE:

• PHYSICAL CONCOMITANTS: EYE BLINKS, HEAD

NODS, INTERJECTIONS OF EXTRA SOUNDS

• VERBAL CONCOMITANTS: WORD

SUBSTITUTIONS

Feelings

CAN BE AS MUCH A PART OF THE DISORDER AS THE

SPEECH BEHAVIORS

• MAKE SPEAKING HARDER, AS FRUSTRATION AND SHAME MAY

INCREASE PHYSICAL TENSION AND IMPEDE FLUENT SPEECH

• EX: FRUSTRATIONS, SHAME, FEAR

Attitudes

FEELINGS THAT HAVE BECOME PERVASIVE ANDARE A PART OF A PERSON’S BELIEFS

disability

limitation stuttering puts on an individuals ability to communicate

handcap

Limitation on person’s life

Development Levels

BORDERLINE STUTTERING – YOUNG PRESCHOOL AGE

• BEGINNING STUTTERING – OLDER PRESCHOOL AGE

• INTERMEDIATE STUTTERING – SCHOOL AGE

• ADVANCED STUTTERING – TEENS AND ADULTS

Oneset

MAY START AS GRADUAL INCREASE IN NORMAL CHILDHOOD

DISFLUENCIES OR MAY START AS SUDDEN APPEARANCE OF

PROLONGATIONS OR BLOCKS

• OFTEN SPORADIC AT OUTSET, COMING AND GOING FOR

PERIODS OF DAYS OR WEEKS BEFORE BECOMING

PERSISTENT

• MAY OCCUR BETWEEN 18 MONTHS AND 12 YEARS

BUT MOST OFTEN BETWEEN 2 AND 3.5 YEARS (AVERAGE

2.8 YEARS)

Prevalence

A MEASURE OF HOW MANY PEOPLE STUTTER AT ANY GIVEN

TIME

2.4 PERCENT IN K, ABOUT 1% IN SCHOOL-AGE

CHILDREN, AND SLIGHTLY LESS THAN 1 PERCENT IN ADULTS.

Incidence

A MEASURE OF HOW MANY PEOPLE HAVE STUTTERED AT

SOME POINT IN THEIR LIVES

• ABOUT 5%

Recovery

SOMEWHERE BETWEEN 70 AND 80 % OF CHILDREN WHO

BEGIN TO STUTTER RECOVER WITHOUT TREATMENT

Anticipation

PEOPLE WHO STUTTER CAN PREDICT

WHICH WORDS THEY WILL STUTTER ON IN A READING

PASSAGE

Consistency

PEOPLE WHO STUTTER TEND TO STUTTER

ON THE SAME WORDS EACH TIME THEY READ A PASSAGE.

Adaptation

PEOPLE WHO STUTTER WILL STUTTER LESS

EACH TIME THEY READ A PASSAGE UP TO ABOUT SIX

READINGS.

Adults who stuttering do so more frequently on

CONSONANTS

• SOUNDS IN WORD-INITIAL POSITION

• SOUNDS IN CONTEXTUAL SPEECH

• NOUNS, VERBS, ADJECTIVES, AND ADVERBS

• LONGER WORDS

• WORDS AT BEGINNINGS OF SENTENCES

• STRESSED SYLLABLES

MANY CONDITIONS HAVE BEEN FOUND WHICH REDUCE OR

ELIMINATE STUTTERING: THESE INCLUDE

WHEN ALONE, WHEN RELAXED

• IN UNISON WITH ANOTHER SPEAKER

• TO AN ANIMAL OR INFANT

• IN TIME OR RHYTHMIC STIMULUS OR WHEN SIGNING, IN A

DIFFERENT DIALECT

• WHILE SIMULTANEOUSLY WRITING, WHILE SWEARING

• IN A SLOW, PROLONGED MANNER

• UNDER LOUD MASKING NOISE, WHILE LISTENING TO

DELAYED AUDITORY FEEDBACK

• WHEN SHADOWING ANOTHER SPEAKER, WHEN REINFORCED

FOR FLUENT SPEECH

A model of stuttering

A NEURODEVELOPMENTAL DISORDER

THAT USUALLY APPEARS IN THE PRESCHOOL YEARS

WHEN LANGUAGE DEVELOPMENT OR THE CHILD’S

ENVIRONMENT CREATE ENOUGH STRESS TO TRIGGER

SPEECH PRODUCTION DISCOORDINATION THAT RESULTS

IN AN EXCESS OF DISFLUENCIES.

THE CHILD MAY REGAIN FLUENCY WHEN STRESSES ARE

REDUCED OR THE CHILD LEARNS TO COMPENSATE.

SOME CHILDREN RECOVER COMPLETELY.

• OTHER CHILDREN PERSIST IN STUTTERING, BECAUSE

THEIR NEURAL PATHWAYS REMAIN INADEQUATE FOR

FLUENCY AND/OR BECAUSE THEY REACT NEGATIVELY TO

THEIR EARLY STUTTERING.

• CHILDREN WHO PERSIST USUALLY DEVELOP LEARNED

BEHAVIORS, MAKING THEIR STUTTERING MORE

CONSPICUOUS.

Prediposing Factors

Those agents that incline a person to stutter and causes one person to be at greater risk than another

for beginning to stutter.

avoidance behavior

a speaker’s attempt to prevent stuttering when they anticipate stuttering in a word or in a situation

Block

A disfluency that is inappropriate stoppage of the flow of air or voice and often the movement of articulators as well

Developmental Stuttering

a term used to denote the most common form of stuttering that develops during childhood

Escape behavior

a speaker’s attempts to terminate a stutter and finish the word

Fluency

the effortless flow of speech

Heterogeneity

differences among various types of disorders

Persistance

stuttering that the child does not spontaneously recover from during early childhood

Prolongation

a disfluency in which the sound or airflow continues but movement of the articulators is stopped

repetitions

a sound syllable or single syllable word that is repeated several times.

Precipitating Factors

Those factors thought to have made stuttering surface or those that brought it to its present state.

May or may not be operating at time of evaluation. Include developmental and environmental factors.

Perpetuating factors

those variables that are continuing or maintaining the stuttering at the present time.

◦ Attitudes of family members

◦ Environmental and physical factors that may be reinforcing stuttering

◦ Unrealistic expectations

◦ Feelings and attitudes about stuttering

◦ Anticipation of fluency failure

◦ Dependence on stuttering by the stutterer or others (spouse)

Three factors interact to result in stuttering

constitutional (predisposing factors)

developmental (precipitating)

enviromental (precipitating)

predisposition

a susceptibility to developing a condition

Increased risk in families

Stuttering tends to run in families. Individuals who stutter are

more likely to have relatives who also stutter compared to the general population6

genetic influence

family studies consistently show a higher prevalence of stuttering

among first-degree relatives (parents, siblings, children) of people who stutter, supporting a genetic contribution to the disorder.

gender difference

These studies have found that males are more likely to stutter than

females, and that the likelihood of a child developing persistent stuttering is influenced by both the gender of the child and the stuttering history of family members

Persistance vs Recovery

Family studies also indicate that persistent stuttering (as

opposed to stuttering that resolves) is more likely in families with a history of chronic stuttering, suggesting genetic factors may influence both the onset and the persistence of stuttering.

Cerebral Dominance for speech

Old and new studies show that individuals who stutter have greater activity in their right

hemispheres than in the left hemispheres, during both fluent and stuttered speech.

◦ The reverse is shown for fluent typical subjects.

Right hemisphere may not be suited for rapid speech production, especially under the stress of increasing language demands and faster speaking as children develop

Electroencephalographic studies

Suggest the brains of people who stutter functioned differently (didn’t find difference)

More activity on the right side of the brain during speech and especially during stuttering

Right frontal operculum (same location in the right hemisphere as Broca’s is in the left)

Connectivity deficits in white matter tracts

Structural connectivity deficits in white matter tracts in the left hemisphere that linked inferior frontal areas and premotor cortex

Deficits in networks connecting auditory-motor and basal ganglia-thalamocortical areas in children who stuttered

Adoption Studies

investigations of stuttering in siblings who were adopted soon after birth and placed with different families

anomaly

a difference from the normal structure or function

Concordance (in twin)

if one twin has a condition (such as stuttering) th other twin also has the condition

Congenital factor

a physical or psychological trauma that occurred at or near birth that ay predispose an individual to develop stuttering

DNA

a double-stranded molecule passed on from a mother and father to a child containing the "instruction book" for inheriting traits

Family studies

examination of family tress of individuals who stutter to determine the frequency and patter of the occurrence of stuttering in relatives.

Gene

a segment of DNA that contributes to an individual's traits, such as height and weight

Genetic Linkage Studies

because two or more genes connected with a disorder are physically close to each other on a chromosome, they are often inherited together in individuals who have that disorder

Persistent Stuttering

stuttering that persists for several years after onset, beyond the time around which natural recovery is likely to occur

Twin Studies

research on the co-occurrence of stuttering of both members of a twin pair if one twin studies

Whole brain instrinsic network connection

connectivity among networks throughout the whole brain can be compared between those who stutter and those who do not

sensory processing

Normal speech depends on intact auditory as well as proprioceptive

and tactile feedback.

Central auditory processing

• Left hemisphere is where central auditory processing take place, but

this may not the he case in people who stutter

• Weaker whiter matter connections

• Mutations in certain genes associated with stuttering – affect auditory-motor integration for speech

Brain electrical potentials reflecting auditory processing

Some or all groups of individuals who stutter have abnormalities in

neural electrical activity when responding to a variety of auditory

stimuli

• Subgroup where DAF helps fluency

Dichotic Listening tests

Deliver simultaneous different stimuli to right and left ears

• Typical speakers report hearing more of the words delivered to the

right ear = left hemisphere processing

• Most (but not all) of these studies indicate that individuals who

stutter do not show the right-ear advantage = shows processing in

right hemisphere

• Because right hemisphere is neither structurally nor functionally designed to process language and speech, stutterers’ processing may be impaired

Key findings in PWS

Slower reaction times, especially when linguistically meaningful

stimuli are used.

• Slower fluent speech, with longer vowels, slower transitions, and

delayed onset of voicing. Slower completion and more errors on

nonspeech tasks of sequencing particularly for more severely

stuttering individuals.

• Slower tapping with their hand at a comfortable rate, they are faster

than controls during fast-tapping conditions but more variable. Close

relatives of stutterers have slower tapping rates than stutterers and

controls but less variability.

• Individuals who stutter are not as able to focus on left-hemisphere

motor control and may be vulnerable to interference from the right

hemisphere or other areas of the left hemisphere. (results from hand

tapping experiments)

• Individuals who stutter are poorer at auditory-motor tracking; they

may not have left-hemisphere advantage for auditory-motor tracking,

and they may be slower at developing a mental model of auditory-

motor relationships

Automatic arousal

treatment should consider addressing anxiety and fear in cleints who manifest them

Temperment implications

here may be a subgroup or particularly reactive/sensitive individuals who need more focus on emotions during treatment.

proprioception

sensory information from the body that conveys position of structures and movement of structures

sensorimotor control

the way all movement is carried out with sensory information used before, during, and after to improve the precision of movement

sensory processing

activity of the brain as it interprets information coming from the senses, such as sounds arriving via the ears and auditory nerves

Physical and motor development

Children who stutter demonstrate motor delays and these delays appear to be greater in children who persist in stuttering rather than recover.

Speech and language development

Onset between 2 and 5 years is the period when children are most

intensively learning to understand and produce language.

Conflicting research

May be a subgroup of children whose language,

while within the normal range, is somewhat delayed. These children

may be those who stuttering persists.

competition for neural resources

this is the concept that the brain has a limited amount of resources that can be applied to tasks such as learning to speak and learning to walk. If some task requires a great deal of attentiion or invoiced extensive neural activity, other tasks preformed at the same time will have fewer resources the same time will have fewer resources and may thus be less well preformed.

language complexity

this refers to gradually more adultlike language acquired by children as they develop

Speech and language environment

the communication style that characterizes people in a child's environment (usually his or her home)

Live events

these are typically stressful events or circumstances in a child's life

avoidance conditioning

Learning that teaches an individual to

engage in behavior that prevents an unpleasant consequence

Classical conditioning

learning occurs through associations or pairings. It is usually associated with elicited behaviors such as reflexes or emotions

learning

a change that takes place as the result of experiences

For classical coniditioning

The stronger the UCR to the UCS the stronger the response to the CS.

Operant conidition forms

an association between a behavior and its consequence

operant coniditioning

learning caused when a behavior is immediately followed by a reward or a punishment

antecedant

events or circumstances that exist in the organism’s environment prior to the occurrence of a behavior and function to cue that behavior

behavior

the observable and measurable action emitted by the organism

consequences

circumstances shortly following a behavior that influence the future probability of that behavior occurring again

maladaptive responses

As a result of the negative attitudes, adult stutterers may actively avoid situations, words, sounds because of their belief that they will be embarrassesed

postponements, circumlocutions, word substitutions

guilt

feeling you have done something wrong

autonomic reactivity

the tendency of the autonomic nervous system to respond quickly and strongly to particular stimuli

anomalous neural organization

brain structure and function that differ from the typical

-sometimes refers to delayed development in myelination of white matter that interferes with connections between different areas of the brain

behavioral inhibition system

a view developed by psychologist Gray that humans are endowed with a hard-wired protective response to a threat; the body's response in this situation is freezing, flight or avoidance

capacities and demands theory

a view of stuttering that suggests that stuttering results when the demand put on a child's speech are greater than the child's capacity for fluency

corticobasal ganglia thalamocortical looop

a neural circuit that processes signals from the cerebral cortex going to several basal ganglia structures and back to the cortex for execution

communicative failure and participatory struggle

a view of stuttering that supposes that stuttering begins when a child experiences problems with communication

-the child may develop a fear of having difficulty, which then causes tension and fragmentation of speeech

covert repair hypothesis

an explanation of stuttering suggesting that stuttering occurs as the result of the brain's stopping production of speech when it detects an error in the plan that the brain has made to produce a word

diagnosoogenic theory

the idea that stuttering is caused by the misdiagnosis of typical disfluencies as stuttering, usually by parents

hemisphereis dominance

in general, the phenomenon that one hemisphere of the brain (left or right) takes the lead or is stronger for a particular function

hemispheric dominance and stuttering

refers to the fact that the left side of the brain is usually more specialized for speech and language than the right side

hypothesis

a specific and testable proposition derived from a theory

Inverse internal models of the speech production system

a concept about how your brain functions when you learn to talk as a child and as you are talking as an adult

Basic idea of the inverse internal models of the speech production system

as a child hears speech in his environment, they story auditory and kinesthetic images of the sounds and words

-during babbling they learn how to send motor commands to their muscles to make those sounds and words. These connections create the internal model for speech production