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What Causes Stuttering?


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The mystery of a sometimes debilitating speech disorder is examined by cognitive neuroscientists.
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PLoS Biology |
Unsolved Mystery
What Causes Stuttering?
Christian Büchel and Martin Sommer
tuttering, with its characteristic
disruption in verbal fl uency, has
been known for centuries; earliest
descriptions probably date back to the
Biblical Moses’ “slowness of speech
and tongue” and his related avoidance
behavior (Exodus 4, 10–13). Stuttering
occurs in all cultures and ethnic groups
(Andrews et al. 1983; Zimmermann et
al. 1983), although prevalence might
differ. Insofar as many of the steps in
how we produce language normally are
still a mystery, disorders like stuttering
are even more poorly understood.
However, genetic and neurobiological
approaches are now giving us clues to
causes and better treatments.
What Is Stuttering?
Stuttering is a disruption in
the fl uency of verbal expression
characterized by involuntary, audible
or silent, repetitions or prolongations
of sounds or syllables (Figure 1). These
are not readily controllable and may be
accompanied by other movements and
by emotions of negative nature such
as fear, embarrassment, or irritation
(Wingate 1964). Strictly speaking,
stuttering is a symptom, not a disease,
but the term stuttering usually refers to
both the disorder and symptom.
Developmental stuttering evolves
before puberty, usually between two
and fi ve years of age, without apparent
brain damage or other known cause
(“idiopathic”). It is important to
distinguish between this persistent
developmental stuttering (PDS),
which we focus on here, and acquired
stuttering. Neurogenic or acquired
stuttering occurs after a defi nable brain
damage, e.g., stroke, intracerebral
hemorrhage, or head trauma. It is
a rare phenomenon that has been
observed after lesions in a variety of
brain areas (Grant et al. 1999; Ciabarra
et al. 2000).
The clinical presentation of
developmental stuttering differs
from acquired stuttering in that it is
particularly prominent at the beginning
of a word or a phrase, in long or
DOI: 10.1371/journal.pbio.0020046.g001
Figure 1. Speech Waveforms and Sound Spectrograms of a Male Speaker Saying “PLoS Biology”
The left column shows speech waveforms (amplitude as a function of time); the right
column shows a time–frequency plot using a wavelet decomposition of these data. In the
top row, speech is fl uent; in the bottom row, stuttering typical repetitions occur at the
“B” in “Biology.” Four repetitions can be clearly identifi ed (arrows) in the spectrogram
(lower right).
Copyright: © 2004 Büchel and Sommer. This is an
open-access article distributed under the terms of
the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduc-
tion in any medium, provided the original work is
properly cited.
Abbreviations: CNS, central nervous system; DTI,
diffusion tensor imaging; fMRI, functional magnetic
resonance imaging; MEG, magnetoencephalography;
MRI, magnetic resonance imaging; PDS, persistent
developmental stuttering; PET, positron emission
Christian Büchel is at NeuroImage Nord in the De-
partment of Neurology at the University of Hamburg
in Hamburg, Germany. Martin Sommer is at the
Department of Clinical Neurophysiology at the Uni-
versity of Göttingen in Göttingen, Germany. E-mail: (CB)
DOI: 10.1371/journal.pbio.0020046
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meaningful words, or syntactically
complex utterances (Karniol 1995;
Natke et al. 2002), and the associated
anxiety and secondary symptoms are
more pronounced (Ringo and Dietrich
1995). Moreover, at repeated readings,
stuttering frequency tends to decline
(adaptation) and to occur at the
same syllables as before (consistency).
Nonetheless, the distinction between
both types of stuttering is not strict. In
children with perinatal or other brain
damage, stuttering is more frequent
than in age-matched controls, and
both types of stuttering may overlap
(Andrews et al. 1983).
Who Is Affected?
PDS is a very frequent disorder,
with approximately 1% of the
population suffering from this
condition. An estimated 3 million
people in the United States and 55
million people worldwide stutter.
Prevalence is similar in all social
classes. In many cases, stuttering
severely impairs communication,
with devastating socioeconomic
consequences. However, there are
also many stutterers who, despite
their disorder, have become famous.
For instance, Winston Churchill had
to rehearse all his public speeches to
perfection and even practiced answers
to possible questions and criticisms to
avoid stuttering. Charles Darwin also
stuttered; interestingly, his grandfather
Erasmus Darwin suffered from the
same condition, highlighting the fact
that stuttering runs in families and is
likely to have a genetic basis.
The incidence of PDS is about 5%,
and its recovery rate is up to about
80%, resulting in a prevalence of PDS
in about 1% of the adult population. As
recovery is considerably more frequent
in girls than in boys, the male-to-female
ratio increases during childhood
and adolescence to reach three or
four males to every one female in
adulthood. It is not clear to what extent
this recovery is spontaneous or induced
by early speech therapy. Also, there is
no good way of predicting whether an
affected child will recover (Yairi and
Ambrose 1999).
The presence of affected family
members suggests a hereditary
component. The concordance rate
is about 70% for monozygotic twins
(Andrews et al. 1983; Felsenfeld et al.
2000), about 30% for dizygotic twins
(Andrews et al. 1983; Felsenfeld et al.
2000), and 18% for siblings of the same
sex (Andrews et al. 1983). Given the
high recovery rate, it may well be that
the group abnormalities observed in
adults refl ects impaired recovery rather
than the causes of stuttering (Andrews
et al. 1983).
Changing Theories
Over the centuries, a variety of
theories about the origin of stuttering
and corresponding treatment
approaches have been proposed. In
ancient Greece, theories referred
to dryness of the tongue. In the
century, abnormalities of the
speech apparatus were thought to
cause stuttering. Thus, treatment
was based on extensive “plastic”
surgery, often leading to mutilations
and additional disabilities. Other
treatment options were tongue-
weights or mouth prostheses (Katz
1977) (Figure 2). In the 20th century,
DOI: 10.1371/journal.pbio.0020046.g002
Figure 2. Two Different Apparatuses to Prevent Stuttering
On the left is a device by Gardner from 1899 to artifi cially add weight to the tongue (United States patent number 625,879). On the
right is a more complex speech apparatus by Peate from 1912 (United States patent number 1,030,964).
February 2004 | Volume 2 | Issue 2 | Page 0161
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stuttering was primarily thought to be
a psychogenic disorder. Consequently,
psychoanalytical approaches and
behavioral therapy were applied
to solve possible neurotic confl icts
(Plankers 1999). However, studies
of personality traits and child–
parent interactions did not detect
psychological patterns consistently
associated with stuttering (Andrews et
al. 1983).
Other theories regard stuttering
as a learned behavior resulting
from disadvantageous external,
usually parental, reactions to normal
childhood dysfl uencies (Johnson
1955). While this model has failed to
explain the core symptoms of stuttering
(Zimmermann et al. 1983), it may
well explain secondary symptoms
(Andrews et al. 1983), and guided early
parental intervention may prevent
persistence into adulthood (Onslow et
al. 2001). The severity of PDS is clearly
modulated by arousal, nervousness, and
other factors (Andrews et al. 1983).
This has led to a two-factor model of
PDS. The fi rst factor is believed to
cause the disorder and is most likely a
structural or functional central nervous
system (CNS) abnormality, whereas the
second factor reinforces the fi rst one,
especially through avoidance learning.
However, one should be careful to
call the latter factor “psychogenic” or
“psychological,” because neuroscience
has shown that learning is not simply
“psychogenic” but leads to measurable
changes in the brain (Kandel and
O’Dell 1992).
In some cases, arousal actually
improves stuttering instead of making
it worse. Consequently, some famous
stutterers have “treated” their stuttering
by putting themselves on the spot.
Anecdotally, the American actor Bruce
Willis, who began stuttering at the age
of eight, joined a drama club in high
school and his stuttering vanished in
front of an audience.
Is Stuttering a Sensory, Motor, or
Cognitive Disorder?
Stuttering subjects as a group
differ from fl uent control groups by
showing, on average, slightly lower
intelligence scores on both verbal
and nonverbal tasks and by delays in
speech development (Andrews et al.
1983; Paden et al. 1999). However,
decreased intelligence scores need to
be interpreted carefully, as stutterers
show a schooling disadvantage of
several months (Andrews et al. 1983).
Associated symptoms comprise delays
in tasks requiring a vocal response
(Peters et al. 1989) and in complex
bimanual timed tasks such as inserting
a string in the eye of a needle (Vaughn
and Webster 1989), whereas many
other studies on sensory–motor
reaction times yielded inconsistent
results (Andrews et al. 1983).
Alterations of auditory feedback (e.g.,
delayed auditory feedback, frequency-
altered feedback), various forms of
other auditory stimulation (e.g., chorus
reading), and alteration of speech
rhythm (e.g., syllable-timed speech)
yield a prompt and marked reduction
of stuttering frequency, which has
raised suspicions of impaired auditory
processing or rhythmic pacemaking
in stuttering subjects (Lee 1951; Brady
and Berson 1975; Hall and Jerger 1978;
Salmelin et al. 1998). Other groups
have also reported discoordinated and
delayed onset of complex articulation
patterns in stuttering subjects (Caruso
et al. 1988; van Lieshout et al. 1993).
The assumption that stuttering might
be a form of dystonia—involuntary
muscle contractions produced by the
CNS—specifi c to language production
(Kiziltan and Akalin 1996) was not
supported by a study on motor cortex
excitability (Sommer et al. 2003).
Neurochemistry, however, may link
stuttering with disorders of a network
of structures involved in the control
of movement, the basal ganglia. An
increase of the neurotransmitter
dopamine has been associated with
movement disorders such as Tourette
syndrome (Comings et al. 1996;
Abwender et al. 1998), which is a
neurological disorder characterized
by repeated and involuntary body
movements and vocal sounds (motor
and vocal tics). Accordingly, like
Tourette syndrome, stuttering improves
with antidopaminergic medication,
e.g., neuroleptics such as haloperidol,
risperidone, and olanzapine (Brady
1991; Lavid et al. 1999; Maguire et al.
2000), and anecdotal reports suggest
that it is accentuated or appears
under treatment with dopaminergic
medication (Koller 1983; Anderson
et al. 1999; Shahed and Jankovic
2001). Hence, a hyperactivity of the
dopaminergic neurotransmitter system
has been hypothesized to contribute to
stuttering (Wu et al. 1995). Although
dopamine antagonists have a positive
effect on stuttering, they all have
side effects that have prevented them
from being a fi rst line treatment of
Lessons from Imaging the Brain
Given reports on acquired stuttering
after brain trauma (Grant et al. 1999;
Ciabarra et al. 2000), one might think
that a lesion analysis (i.e., asking the
question where do all lesions that lead
to stuttering overlap) could help to
nd the location of an abnormality
linked to stuttering. Unfortunately,
lesions leading to stuttering are
widespread and do not seem to follow
an overlapping pattern. Even the
contrary has been observed, a thalamic
stroke after which stuttering was
“cured” in a patient (Muroi et al. 1999).
In fl uent speakers, the left language-
dominant brain hemisphere is most
active during speech and language
tasks. However, early studies on EEG
lateralization already strongly suggested
abnormal hemispheric dominance
(Moore and Haynes 1980) in stutterers.
With the advent of other noninvasive
brain imaging techniques like positron
emission tomography (PET) and
functional magnetic resonance imaging
(fMRI), it became possible to visualize
brain activity of stutterers and compare
these patterns to fl uent controls.
Following prominent theories that
linked stuttering with an imbalance
of hemispherical asymmetry (Travis
1978; Moore and Haynes 1980), an
important PET study (Fox et al. 1996)
reported increased activation in the
right hemisphere in a language task in
developmental stutterers. Another PET
study (Braun et al. 1997) confi rmed
this result, but added an important
detail to the previous study: Braun
and colleagues found that activity in
the left hemisphere was more active
during the production of stuttered
speech, whereas activation of the
right hemisphere was more correlated
with fl uent speech. Thus, the authors
concluded that the primary dysfunction
is located in the left hemisphere and
that the hyperactivation of the right
hemisphere might not be the cause of
stuttering, but rather a compensatory
process. A similar compensatory
process has been observed after
stroke and aphasia, where an intact
right hemisphere can at least partially
compensate for a loss of function
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(Weiller et al. 1995). Right hemisphere
hyperactivation during fl uent speech
has been more recently confi rmed with
fMRI (Neumann et al. 2003).
PET and fMRI have high spatial
resolution, but because they only
indirectly index brain activity
through blood fl ow, their temporal
resolution is rather limited.
Magnetoencephalography (MEG) is
the method of choice to investigate
ne-grained temporal sequence of
brain activity. Consequently, MEG was
used to investigate stutterers and fl uent
controls reading single words (Salmelin
et al. 2000). Importantly, stutterers
were reported to have read most single
words fl uently. Nevertheless, the data
showed a clear-cut difference between
stutterers and controls. Whereas fl uent
controls activated left frontal brain
areas involved in language planning
before central areas involved in speech
execution, this pattern was absent, even
reversed, in stutterers. This was the
rst study to directly show a neuronal
correlate of a hypothesized speech
timing disorder in stutterers (Van
Riper 1982).
Thus, functional neuroimaging
studies have revealed two important
facts: (i) in stutterers, the right
hemisphere seems to be hyperactive,
and (ii) a timing problem seems
to exist between the left frontal
and the left central cortex. The
latter observation also fi ts various
observations that have shown that
stutterers have slight abnormalities in
complex coordination tasks, suggesting
that the underlying problem is located
around motor and associated premotor
brain areas.
Are there structural abnormalities
that parallel the functional
abnormalities? The fi rst anatomical
study to investigate this question used
high-resolution MR scans and found
abnormalities of speech–language
areas (Broca’s and Wernicke’s
area) (Foundas et al. 2001). In
addition, these researchers reported
abnormalities in the gyrifi cation
pattern. Gyrifi cation is a complex
developmental procedure, and
abnormalities in this process are an
indicator of a developmental disorder.
Another recent study investigated
the hypothesis that impaired cortical
connectivity might underlie timing
disturbances between frontal and
central brain regions observed in MEG
studies (Figure 3). Using a new MRI
technique, diffusion tensor imaging
(DTI), that allows the assessment
of white matter ultrastructure,
investigators saw an area of decreased
white matter tract coherence in the
Rolandic operculum (Sommer et al.
2002). This structure is adjacent to
the primary motor representation of
tongue, larynx, and pharynx (Martin
et al. 2001) and the inferior arcuate
fascicle linking temporal and frontal
language areas, which both form
a temporofrontal language system
involved in word perception and
production (Price et al. 1996). It is
thus conceivable that disturbed signal
transmission through fi bers passing
the left Rolandic operculum impairs
the fast sensorimotor integration
necessary for fl uent speech production.
This theory also explains why the
normal temporal pattern of activation
between premotor and motor cortex
is disturbed (Salmelin et al. 2000)
and why, as a consequence, the right
hemisphere language areas try to
compensate for this defi cit (Fox et al.
These new data also provide a theory
to explain the mechanism of common
uency-inducing maneuvers like chorus
reading, singing, and metronome
reading that reduce stuttering
instantaneously. All these procedures
involve an external signal (i.e., other
readers in chorus reading, the music
in singing, and the metronome
itself). All these external signals feed
into the “speech production system”
through the auditory cortex. It is thus
possible that this external trigger
signal reaches speech-producing
central brain areas by circumventing
the frontocentral disconnection and
is able to resynchronize frontocentral
decorrelated activity. In simple terms,
these external cues can be seen as an
external “pacemaker.”
Future Directions in Research
There are numerous outstanding
issues in stuttering. If structural
changes in the brain cause PDS, the key
question is when this lesion appears.
Although symptoms are somewhat
different, it would be interesting to fi nd
out to what extent transient stuttering
(which occurs in 3%–5% in childhood)
is linked to PDS. It is possible that all
children who show signs of stuttering
develop a structural abnormality during
development, but this is transient in
those who become fl uent speakers.
If this is the case, it is even more
important that therapy starts as early
as possible if it is to have most impact.
This question can now be answered
with current methodology, i.e.,
noninvasive brain imaging using MRI.
DOI: 10.1371/journal.pbio.0020046.g003
Figure 3. Decreased Fiber Coherence
Decreased fi ber coherences, as observed with DTI, in persistent developmental
stutterers compared with a fl uent control group. A red dot indicates the peak
difference in a coronal (top left), axial (top right), and a sagittal (bottom) slice.
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Given that boys are about four
times less likely to recover from
stuttering than girls, it is tempting
to speculate that all stutterers have
a slight abnormality, but only those
that can use the right hemisphere
for language can develop into fl uent
speakers. Language lateralization
is less pronounced in women
(McGlone 1980) and might therefore
be related to the fact that women
show an overall lower incidence in
PDS. Again, a developmental study
comparing children who stutter with
uent controls and, most importantly,
longitudinal studies on these children
should be able to answer these
It is unlikely that stuttering is
inherited in a simple fashion.
Currently, a multifactorial model for
genetic transmission is most likely.
Moreover, it is unclear whether a
certain genotype leads to stuttering
or only represents a risk factor and
that other environmental factors are
necessary to develop PDS. Again, this
question might be answered in the near
future, as the National Institutes of
Health has recently completed the data
collection phase of a large stuttering
sample for genetic linkage analysis. 
We thank Tobias Sommer and Andreas
Starke for fruitful discussions and the
Volkswagen Foundation as well as the
Deutsche Forschungsgemeinschaft for
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... Persisting developmental stuttering affects an estimated 55 million speakers worldwide (Büchel & Sommer, 2004) and often involves emotional and psychosocial consequences, in addition to overt speech symptoms, even in young children (Yairi & Ambrose, 2013). Current theoretical perspectives point to a multifactorial etiology, with stuttering arising from complex interactions of multiple factors (genetic, neurobiological, linguistic, emotional, cognitive, environmental) over time (Smith & Weber, 2017). ...
Purpose Contemporary motor theories indicate that well-practiced movements are best performed automatically, without conscious attention or monitoring. We applied this perspective to speech production in school-age children and examined how dual-task conditions that engaged sustained attention affected speech fluency, speech rate, and language productivity in children with and without stuttering disorders. Method Participants included 47 children (19 children who stutter, 28 children who do not stutter) from 7 to 12 years of age. Children produced speech in two baseline conditions with no concurrent task and under a dual-task condition requiring sustained attention to on-screen stimuli. Measures of speech fluency, speech rate, and language productivity were obtained for each trial and compared across conditions and groups. Results Dual-task conditions resulted in a reduction in stutter-like disfluencies relative to the initial baseline speaking condition. Effects were similar for both groups of children and could not be attributed to decreases in language productivity or a simple order effect. Conclusions Findings suggest that diverting attention during the process of speech production enhances speech fluency in children, possibly by increasing the automaticity of motor speech sequences. Further research is needed to clarify neurophysiological mechanisms underlying these changes and to evaluate potential clinical applications of such effects. Supplemental Material
... Stutterer will produce repeated words, sounds, sentences or sudden involuntary breaks which might lead to abnormal physical and emotional behaviors as the speaker struggles to end a particular sentence [25]. Stuttering could be developmental, which is the most common types, or acquired secondary to brain injury or emotional trauma [26,27]. Salihović et al. studied the voice characteristics in stuttering children in their case-control experimental study and found that the abnormal functioning of the larynx and high muscular tension as well as subglottic pressure with lack of coordination and control of the respiratory and laryngeal muscles will lead to voice disorders [28]. ...
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Hoarseness in school-aged children may affect their educational achievement and interfere with their communication and social skills development. The global prevalence of hoarseness in school-aged children ranges between 6% and 23%. To the best of our knowledge, there is a scarcity of studies describing the prevalence or determinates of hoarseness in Saudi school-aged children. Our aim was to measure the prevalence of hoarseness among school-aged children and to identify its determinants. A cross-sectional questionnaire-based survey was used that included randomly selected primary and early childhood schools from private and governmental sectors in Saudi Arabia. The data were collected using a questionnaire which was self-completed by the children’s parents and covered the following aspects: sociodemographic features, health and its related comorbidities about children and their families, attendance and performance in school, child’s voice tone, past history of frequent crying during infancy, history of letter pronunciation problems and stuttering, the Reflux Symptom Index (RSI) and the Children’s Voice Handicap Index-10 for parents (CVHI-10-P). Determinants of hoarseness were investigated using the SPSS software (version 20). The mean age of the study children (n = 428) was 9.05 years (SD = 2.15), and 69.40% of them were male. The rate of hoarseness in the participants was 7.5%. Hoarseness was significantly common in children with a history of excessive infancy crying (p = 0.006), letter pronunciation issues (especially ‘R’ and ‘S’; p = 0.003), and stuttering (p = 0.004) and in those with a previous history of hoarseness (p = 0.023). In addition, having the symptoms of gastrointestinal reflux increased the risk of hoarseness by four times (OR = 4.77, 95% CI = 2.171, 10.51). In summary, hoarseness in children may be dangerously underestimated, as it may reflect the presence of speech problems, in addition to the presence of laryngopharyngeal reflux (LPR). Hoarseness was assumed on the basis of parental complaints. Therefore, further research with diagnoses based on a clinical assessment is needed to understand the magnitude of the hoarseness problem and its consequences in children.
... Previous research has found that those who stammer may avoid participating in activities that involve social communicative and/or anxiety-provoking situations (Blumgart et al., 2010a;Craig et al., 2009;Craig & Tran, 2006;Iverach & Rapee, 2014;Messenger et al., 2004). Stammering is a disruption in the fluency of verbal expression characterised by involuntary, audible or silent repetitions, prolongations or complete blocks of sounds, syllables or words (Büchel & Sommer, 2004;Nicolosi et al., 2004;Wingate, 1964). It has a worldwide prevalence of 5-8 % (Yairi & Ambrose, 2013). ...
Purpose: Exercise and sport participation lead to many physical and psychosocial benefits. However, barriers to exercise and sporting participation exist. This study aims to examine if stammering acts as a barrier to exercise and sporting participation in adults. Methods: One hundred and six adults who stammer (male n = 74, female n = 32; 33.83 ± 14.5 years) completed an anonymous questionnaire which evaluated their stammering history, exercise and sporting participation, views on why they exercise, whether stammering prevented or negatively influenced their participation in exercise or sport. Descriptive statistics were then calculated. Results: The majority (90.6 %) of participants take part in some form of exercise/sport. However, their stammer prevented them from taking part in a specific exercise/sport at least once (49.1 %), due to being too nervous to introduce themselves, nervous or fear of stammering or being judged. Their stammer also negatively impacted their involvement when participating at least once (42.4 %), with not feeling part of the team and fear of speaking reported. Self-disclosure of their stammer and improving awareness of stammering were identified as common facilitators for taking part in exercise/sport. Conclusion: Stammering was not found to impact general participation in exercise and sport but was identified as a barrier to partaking in specific exercise and sport and their enjoyment thereof. Encouraging those who stammer to inform those involved in sport and exercise (e.g. fellow players, coaches) about their stammer and improving stammer awareness across the general and sporting population may encourage further participation in exercise and sport in those who stammer.
... 'the door door is open') (Tumanova, Conture, Lambert, & Walden, 2014). Stuttering is a reasonably frequent speech disorder, affecting approximately 1% of the adult population worldwide (Buchel & Sommer, 2004). Its most common form is referred to as developmental stuttering, and usually evolves around the age of two to five without being linked to any apparent brain damage or other known cause. ...
Purpose The current study examines how speech disfluencies manifest themselves in the two languages of bilingual persons who stutter, starting from the hypothesis that stuttering is associated with an attentional deficit at the level of speech production. Methods Twenty-eight bilingual people who stutter performed a spontaneous and a controlled speech production task, once in their dominant and once in their non-dominant language. The controlled production task (i.e. a network description task) was carried out once under a full-attention condition and once under a divided-attention condition where a non-linguistic, pitch discrimination task was performed simultaneously. Results In both the spontaneous and the controlled speech task, bilingual persons who stutter produced more (typical and stuttering-like) disfluencies in their L2 than in their L1. Furthermore, whereas the typical disfluencies increased when attention was directed away from speech production, stuttering-like disfluencies decreased. This effect was however restricted to L2. In addition, L2 proficiency was generally found to be a predicting factor, with higher proficiency leading to fewer disfluencies. Conclusions These results suggest that speaking in a non-dominant language increases both typical and stuttering-like disfluencies in bilingual persons who stutter, but also that these two types of dysfluencies differ regarding their attentional origins. Our findings offer further support for attentional accounts of stuttering and have both theoretical and clinical implications.
Purpose To determine the relationships between stuttering severity and avoidance of speaking on patient centeredness of healthcare system interactions in a sample of persons who stutter. Methods This quantitative study utilized cross-sectional electronic surveys to assess the experiences of one-hundred-twenty-two adults who stutter in the United States with primary care physicians. The surveys evaluated: 1) self-reported stuttering severity and avoidance of speaking; and 2) self-reported patient-centeredness of healthcare interactions. We used multivariate linear regression to model relationships between independent and dependent variables, controlling for age, gender, patient-provider relationship duration, race/ethnicity, the presence of comorbid conditions, and household income. Results Patient self-reported avoidance of speaking was significantly negatively associated with self-reported patient-centeredness of healthcare interactions. Patient self-reported stuttering severity was not significantly associated with patient-centeredness. Conclusion Our findings present evidence that internal non-observable behaviors among persons who stutter, such as avoiding speaking, are associated with negative impact on healthcare interactions. Speech-language pathologists may want to discuss healthcare challenges with their clients and elicit communication barriers to inspire positive interactions within the healthcare system.
Objective: The aim of the present study was to investigate the five different components of self-perception (academic competence, social acceptance, athletic competence, physical appearance and school behavior), and to identify the dimensions that affect self-esteem in children with Childhood onset Fluency Disorder (CoFD). Material and Methods: The study sample consisted of thirty children with CoFD and, as controls, thirty children without CoFD, aged from 9 to 11;7 years old. The following instruments were used: (1) the Greek version of Self-Perception Profile for Children (SPPC), (2) the “Children’s Phonetic and Phonological development assessment” and, (3) a demographic characteristics form. Results: Results revealed that while children with CoFD did report lower perceived academic competence than did those of the control group, and their academic competence self-perception shaped both their self-esteem and their school behavior self-perception. Moreover, academic competence self-perception was found to mediate in the relationship between CoFD, self-esteem and school behavior self-perception. Conclusions: Perceived academic competence in children with CoFD is linked to self-esteem and perceived school behavior, and this may impact on their relationships, emotional health and overall well-being. Health professionals should become able to estimate coexisting psychological difficulties and negative behaviors of parents or teachers that may affect the children's self-esteem. Furthermore, they should be able to suggest targeted psychological interventions for children and parents, while in the same frame teachers need to be properly trained about the management of stuttering in the classroom. The role of the speech therapist in the school context for in-service provision of information is therefore considered to be of paramount importance.
Introduction : Most of the previous articulatory studies of stuttering have focussed on the fluent speech of people who stutter. However, to better understand what causes the actual moments of stuttering, it is necessary to probe articulatory behaviors during stuttered speech. We examined the supralaryngeal articulatory characteristics of stuttered speech using real-time structural magnetic resonance imaging (RT-MRI). We investigated how articulatory gestures differ across stuttered and fluent speech of the same speaker. Methods : Vocal tract movements of an adult man who stutters during a pseudoword reading task were recorded using RT-MRI. Four regions of interest (ROIs) were defined on RT-MRI image sequences around the lips, tongue tip, tongue body, and velum. The variation of pixel intensity in each ROI over time provided an estimate of the movement of these four articulators. Results : All disfluencies occurred on syllable-initial consonants. Three articulatory patterns were identified. Pattern 1 showed smooth gestural formation and release like fluent speech. Patterns 2 and 3 showed delayed release of gestures due to articulator fixation or oscillation respectively. Block and prolongation corresponded to either pattern 1 or 2. Repetition corresponded to pattern 3 or a mix of patterns. Gestures for disfluent consonants typically exhibited a greater constriction than fluent gestures, which was rarely corrected during disfluencies. Gestures for the upcoming vowel were initiated and executed during these consonant disfluencies, achieving a tongue body position similar to the fluent counterpart. Conclusion : Different perceptual types of disfluencies did not necessarily result from distinct articulatory patterns, highlighting the importance of collecting articulatory data of stuttering. Disfluencies on syllable-initial consonants were related to the delayed release and the overshoot of consonant gestures, rather than the delayed initiation of vowel gestures. This suggests that stuttering does not arise from problems with planning the vowel gestures, but rather with releasing the overly constricted consonant gestures.
Conference Paper
Stuttering means that children have difficulties in rhythm, sound, syllable, word and phrase repetitions, or flow of speech cut in the form of extension or block form. In the International Classification of Diseases (1992)) (International Classification of Diseases-10 "ICD-10"), it was defined as speech disturbances emerging as a result of repetitions or cut of one sound involuntarily although an individual knows what s/he wants to say. The number of children with stuttering applied to the Counseling and Research Centre due to speech and language difficulties because of having stuttering was determined as two thousand and nine hundred and forty six reported with a research carried out by the Turkish Ministry of National Education in schools (2012). When these children have been classified according to the types of difficulties, it is seen that stuttering is 42 percent (42%), rhythm disorder is 36 percent (36%), delayed speech is 16 percent (16%), and other speech and language difficulties are 6 percent (% 6) (Sarı, 2014). However, in Turkey, there are few studies related to the difficulties that stuttering children encounter in their academic and social settings. Therefore, the aim of this study is to determine what kind of difficulties children with stuttering have in primary schools in Konya province in terms of their academic and social activities. In this research, semi-structured interview method as one of the qualitative research methods was used because the researcher wanted to receive rich and detailed information on their difficulties which the children face in academic and social activities. The data were collected by using semi-structured interview forms developed by the researchers with selected 32 students from the primary schools. The data collected for this research were analysed with "Content Analysis Technique". According to the results of this research, children with stuttering have considerable difficulties in the interactions of student and teacher, and student and student. Additionally, it has been observed that children with stuttering exhibited negative attitudes towards participating social and academic activities or taking part in social activities. In addition to these, other children have lack of social interaction with those who stutter. This attitude caused children with stuttering to fall behind in learning concepts and skills during their education.
There is a general consensus regarding the essential nature of effective communication in the workplace. However, in practice, there seems to be a narrow and specific definition of communication effectiveness that goes above and beyond the ability to deliver information. This perpetuates stigma surrounding communication disorders such as stuttering, and helps drive negative employment outcomes for those who stutter. In this paper, we develop a model of Stuttering Stigma in Organizational Communication (SSOC) in order to better understand the complexity surrounding communication, stuttering, and stigma. We discuss implications for organizations and strategies for stigma reduction.
Purpose The purpose of this study was to examine dysfluency characteristics of individuals with Parkinson Disease (PD) relative to linguistic features of grammatical class and position within word. Few studies have reported dysfluency characteristics of PD relative to these characteristics. Those that do report on these characteristics include one case study and a study of six individuals with PD. No previous research is known to have examined dysfluency related to grammatical class and position within words for a large sample of individuals with PD. Method Dysfluencies from 32 individuals with PD were analyzed according to position within a word and grammatical class. Results Participants produced significantly more dysfluencies in the initial position of words compared to medial or final positions, and a significantly higher percent dysfluency for content words versus function words. Conclusion Effects of linguistic features of grammatical class and position within a word on dysfluencies are present within a population with PD and are similar to the linguistic features associated with developmental stuttering. Clinical implications of the effect of linguistic features on speech dysfluencies in PD are discussed.
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Summary The neural systems involved in hearing and repeating single words were investigated in a series of experiments using PET. Neuropsychological and psycholinguistic studies implicate the involvement of posterior and anterior left perisylvian regions (Wernicke's and Broca's areas). Although previous functional neuroimaging studies have consistently shown activation of Wernicke's area, there has been only variable implication of Broca's area. This study demonstrates that Broca's area is involved in both auditory word perception and repetition but activation is dependent on task (greater during repetition than hearing) and stimulus presentation (greater when hearing words at a slow rate). The peak of frontal activation in response to hearing words is anterior to that associated with repeating words; the former is probably located in Brodmann's area 45, the latter in Brodmann's area 44 and the adjacent precentral sulcus. As Broca's area activation is more subtle and complex than that in Wernicke's area during these tasks, the likelihood of observing it is influenced by both the study design and the image analysis technique employed. As a secondary outcome from the study, the response of bilateral auditory association cortex to ‘own voice’ during repetition was shown to be the same as when listening to ‘other voice’ from a prerecorded tape.
Speaking in the claustrum: The psychodynamics of stuttering. - The author outlines the psychoanalytic theory of stuttering and, discussing material from the analysis of a stutterer and its transference and countertransference processes, puts forward a new hypothesis of the psychodynamics of stuttering in conjunction with Meltzer's theory of the claustrum. He argues that the stutterer is working out intolerable experiences of separation from the primary object and a resulting catastrophic experience of the oedipal situation through an unconscious fantasy in which anal qualities are conferred an the internal maternal object by a predominating hatred. The intrusive identification of parts of the self in the maternal rectum gives rise to a claustrophobic experiential world in which all obstacles that are encountered between self and object must be eliminated. The anal-sadistic object space of the claustrum is projected to the external object space and thus also to the mouth as the origin of the sound envelope, where it produces both a lifeless sound envelope and a torn content, i.e. stuttered sounds, words and sentences. Correspondingly, a dead speech melody and broken words have their parallels in object relations that are characterised by an attack on linking and by psychic withdrawal.
Although the cerebral cortex has been implicated in the control of swallowing, the functional organization of the human cortical swallowing representation has not been fully documented. Therefore, the present study determined the cortical representation of swallowing in fourteen healthy right-handed female subjects using single-event-related functional magnetic resonance imaging (fMRI). Subjects were scanned during three swallowing activation tasks: a naive saliva swallow, a voluntary saliva swallow, and a water bolus swallow. Swallow-related laryngeal movement was recorded simultaneously from the output of a bellows positioned over the thyroid cartilage. Statistical maps were generated by computing the difference between the magnitude of the voxel time course during 1) a single swallowing trial and 2) the corresponding control period. Automatic and volitional swallowing produced activation within several common cortical regions, the most prominent and consistent being located within the lateral precentral gyrus, lateral postcentral gyrus, and right insula. Activation foci within the superior temporal gyrus, middle and inferior frontal gyri, and frontal operculum also were identified for all swallowing tasks. In contrast, activation of the caudal anterior cingulate cortex was significantly more likely in association with the voluntary saliva swallow and water bolus swallow than the naive swallow. These findings support the view that, in addition to known brain stem areas, human swallowing is represented within a number of spatially and functionally distinct cortical loci which may participate differentially in the regulation of swallowing. Activation of the insula was significantly lateralized to the right hemisphere for the voluntary saliva swallow, suggesting a functional hemispheric dominance of the insula for the processing of swallowing.
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This report follows by 23 years correspondence between Wendell Johnson and Sven Liljeblad in which Liljeblad pointed out that among North American "nonstuttering" Indians there were Indians who stuttered, fie also reported several terms that referred to stuttering. An unpublished study reported by Frank confirmed Liljeblad's claims. Since we must rely on published reports, it is important to get these findings into print for future scholars. Though these findings in no way refute the claimed importance of linguistics and cultural variables as contributing to the development of stuttering, they do call to question evidence supporting the view that stuttering is a diagnosogenic disorder. Historical and sosciological issues related to these contradictory findings are similar to those discussed by Freeman.
The alpha hemispheric asymmetries of normal-speaking males, normal-speaking females and male stutterers were examined with electroencephalographic (EEG) techniques during exposure to connected speech and connected nonlinguistic stimuli. The subject selection was controlled for familial right handedness. The stutterers showed significantly less alpha in their right hemispheres for both verbal and nonverbal tasks. The findings are discussed in terms of possible variables affecting hemispheric processing in normal males, females, and stutterers. The hypothesis that stuttering may be a linguistic segmentation dysfunction is presented.
The research literature on stuttering is extensive, spanning etiology, natural history, phenomenology, and treatment. In this review, existing empirical knowledge is distilled by attending only to replicated findings. These are designated as "facts." Facts concerning the natural history of idiopathic stuttering highlight early childhood onset, probability of recovery, and importance of a positive family history of stuttering. Corroborated evidence on stutterer-nonstutterer differences concerns intelligence distribution, speech development, central auditory function, and sensory-motor response. Predictable changes in stuttering frequency, and even total elimination of stuttering, occur under a remarkable variety of conditions. Review of therapies revealed two that satisfied the most stringent criteria for good treatment. Various theoretical positions are examined for their fit with the established facts. A model of stuttering as a genetically determined reduction in central capacity for efficient sensory-motor integration is preferred, provided acquisition of secondary symptoms is attributed to instrumental learning.
Stuttering is a common speech disorder that causes significant distress and may cause social maladjustment and hinder occupational potential. Treatments for chronic stuttering in adults can control stuttering by teaching the speaker to use a newspeech pattern. However, these treatments are resource intensive and relapse prone, and they produce speech that sounds unnatural to the listener and feels unnatural to the speaker. This article describes the development and evaluation of an operant treatment for early stuttering. Parents are trained to present verbal contingencies for stuttered and stutter-free speech during everyday speaking situations with their children. The authors overview outcome data from several studies that suggest that this program produces relapse-free control of stuttered speech in preschool children in the medium and long term in a cost-effective manner.
Dual functional brain asymmetry refers to the notion that in most individuals the left cerebral hemisphere is specialized for language functions, whereas the right cerebral hemisphere is more important than the left for the perception, construction, and recall of stimuli that are difficult to verbalize. In the last twenty years there have been scattered reports of sex differences in degree of hemispheric specialization. This review provides a critical framework within which two related topics are discussed: Do meaningful sex differences in verbal or spatial cerebral lateralization exist? and, if so, Is the brain of one sex more symmetrically organized than the other? Data gathered on right-handed adults are examined from clinical studies of patients with unilateral brain lesions; from dichotic listening, tachistoscopic, and sensorimotor studies of functional asymmetries in non-brain-damaged subjects; from anatomical and electrophysiological investigations, as well as from the developmental literature. Retrospective and descriptive findings predominate over prospective and experimental methodologies. Nevertheless, there is an impressive accummulation of evidence suggesting that the male brain may be more asymmetrically organized than the female brain, both for verbal and nonverbal functions. These trends are rarely found in childhood but are often significant in the mature organism.
Vast arrays of medications have been used, with limited success, to manage stuttering. Haloperidol and risperidone are the only two medications that have shown efficacy via double-blind studies in controlling stuttering symptoms. We present the first case reports of olanzapine in the management of stuttering. Three case histories are presented: a 10-year-old boy, a 16-year-old male adolescent with developmental stuttering, and a 9-year-old boy with medication-induced stuttering whose symptoms are successfully controlled with olanzapine. These case studies suggest that olanzapine may be a pharmacologic option in the management of stuttering.