Localization of stuttering based on causal brain lesions.

Stuttering affects approximately 1 in 100 adults and can result in significant communication problems and social anxiety. It most often occurs as a developmental disorder but can also be caused by focal brain damage. These latter cases may lend unique insight into the brain regions causing stuttering. Here, we investigated the neuroanatomical substrate of stuttering using three independent datasets: (i) case reports from the published literature of acquired neurogenic stuttering following stroke (n = 20, 14 males/six females, 16-77 years); (ii) a clinical single study cohort with acquired neurogenic stuttering following stroke (n = 20, 13 males/seven females, 45-87 years); and (iii) adults with persistent developmental stuttering (n = 20, 14 males/six females, 18-43 years). We used the first two datasets and lesion network mapping to test whether lesions causing acquired stuttering map to a common brain network. We then used the third dataset to test whether this lesion-based network was relevant to developmental stuttering. In our literature dataset, we found that lesions causing stuttering occurred in multiple heterogeneous brain regions, but these lesion locations were all functionally connected to a common network centred around the left putamen, including the claustrum, amygdalostriatal transition area and other adjacent areas. This finding was shown to be specific for stuttering (PFWE < 0.05) and reproducible in our independent clinical cohort of patients with stroke-induced stuttering (PFWE < 0.05), resulting in a common acquired stuttering network across both stroke datasets. Within the common acquired stuttering network, we found a significant association between grey matter volume and stuttering impact for adults with persistent developmental stuttering in the left posteroventral putamen, extending into the adjacent claustrum and amygdalostriatal transition area (PFWE < 0.05). We conclude that lesions causing acquired neurogenic stuttering map to a common brain network, centred to the left putamen, claustrum and amygdalostriatal transition area. The association of this lesion-based network with symptom severity in developmental stuttering suggests a shared neuroanatomy across aetiologies.

Stuttering associated with a pathogenic variant in the chaperone protein cyclophilin 40.

Stuttering is a common speech disorder that interrupts speech fluency and tends to cluster in families. Typically, stuttering is characterized by speech sounds, words or syllables which may be repeated or prolonged and speech that may be further interrupted by hesitations or 'blocks'. Rare variants in a small number of genes encoding lysosomal pathway proteins have been linked to stuttering. We studied a large four-generation family in which persistent stuttering was inherited in an autosomal dominant manner with disruption of the cortico-basal-ganglia-thalamo-cortical network found on imaging. Exome sequencing of three affected family members revealed the PPID c.808C>T (p.Pro270Ser) variant that segregated with stuttering in the family. We generated a Ppid p.Pro270Ser knock-in mouse model and performed ex vivo imaging to assess for brain changes. Diffusion-weighted MRI in the mouse revealed significant microstructural changes in the left corticospinal tract, as previously implicated in stuttering. Quantitative susceptibility mapping also detected changes in cortico-striatal-thalamo-cortical loop tissue composition, consistent with findings in affected family members. This is the first report to implicate a chaperone protein in the pathogenesis of stuttering. The humanized Ppid murine model recapitulates network findings observed in affected family members.

Inefficient speech-motor control affects predictive speech comprehension: atypical electrophysiological correlates in stuttering.

Listeners predict upcoming information during language comprehension. However, how this ability is implemented is still largely unknown. Here, we tested the hypothesis proposing that language production mechanisms have a role in prediction. We studied 2 electroencephalographic correlates of predictability during speech comprehension-pre-target alpha-beta (8-30 Hz) power decrease and the post-target N400 event-related potential effect-in a population with impaired speech-motor control, i.e. adults who stutter (AWS), compared to typically fluent adults (TFA). Participants listened to sentences that could either constrain towards a target word or not, modulating its predictability. As a complementary task, participants also performed context-driven word production. Compared to TFA, AWS not only displayed atypical neural responses in production, but, critically, they showed a different pattern also in comprehension. Specifically, while TFA showed the expected pre-target power decrease, AWS showed a power increase in frontal regions, associated with speech-motor control. In addition, the post-target N400 effect was reduced for AWS with respect to TFA. Finally, we found that production and comprehension power changes were positively correlated in TFA, but not in AWS. Overall, the results support the idea that processes and neural structures prominently devoted to speech planning also support prediction during speech comprehension.

Dissecting structural connectivity of the left and right inferior frontal cortex in children who stutter.

Inferior frontal cortex pars opercularis (IFCop) features a distinct cerebral dominance and vast functional heterogeneity. Left and right IFCop are implicated in developmental stuttering. Weak left IFCop connections and divergent connectivity of hyperactive right IFCop regions have been related to impeded speech. Here, we reanalyzed diffusion magnetic resonance imaging data from 83 children (41 stuttering). We generated connection probability maps of functionally segregated area 44 parcels and calculated hemisphere-wise analyses of variance. Children who stutter showed reduced connectivity of executive, rostral-motor, and caudal-motor corticostriatal projections from the left IFCop. We discuss this finding in the context of tracing studies from the macaque area 44, which leads to the need to reconsider current models of speech motor control. Unlike the left, the right IFCop revealed increased connectivity of the inferior posterior ventral parcel and decreased connectivity of the posterior dorsal parcel with the anterior insula, particularly in stuttering boys. This divergent connectivity pattern in young children adds to the debate on potential core deficits in stuttering and challenges the theory that right hemisphere differences might exclusively indicate compensatory changes that evolve from lifelong exposure. Instead, early right prefrontal connectivity differences may reflect additional brain signatures of aberrant cognition-emotion-action influencing speech motor control.

Mothers' and fathers' attitudes toward stuttering in the Middle East compared to Europe and North America.

BACKGROUND: Parents play a central role in the treatment of childhood stuttering. Addressing parental attitudes toward stuttering is helpful therapeutically. The extent to which differences in attitudes toward stuttering exist on the basis of sex, geographical region and parental status (e.g., parent of a stuttering child, parent of a nonstuttering child, nonparent) is unclear. Many studies investigating such factors have used the Public Opinion Survey of Human Attributes-Stuttering (POSHA-S) questionnaire. A large POSHA-S database has collected responses from over 20 000 people from 49 countries. AIMS: The aim of this study was to use the POSHA-S database to examine the extent to which the following variables influence attitudes toward stuttering: (a) parents' sex (mothers vs. fathers), (b) geographic region (Middle East vs. Europe and North America), (c) parents' children (stuttering vs. nonstuttering) and (d) parental status (parents versus nonparents). METHODS & PROCEDURES: Data used in this study were extracted from selected, relevant studies that administered the POSHA-S to respondents. The Overall Stuttering Scores were compared on the basis of sex and parent status (i.e., mothers and fathers; nonparent women and men) and were then compared within and across the two geographical areas. Group comparisons were performed using analysis of variance followed by independent t tests, and Cohen's d was calculated to determine effect sizes. OUTCOMES & RESULTS: Statistically significant differences were observed upon the basis of geographical region. In general, male parents and nonparents tend to have more positive stuttering attitudes among the Middle Eastern samples while female parents and nonparents tend to show more positive attitudes in European and North American samples in the POSHA-S database. Effect sizes were small for all comparisons. CONCLUSIONS & IMPLICATIONS: The effect of geographic region and culture may predict sex-based differences among mothers' and fathers' attitudes toward stuttering; however, the clinical significance is unclear. Additional research is needed to better understand how children who stutter are affected by their parents' attitudes toward stuttering. WHAT THIS PAPER ADDS: What is already known on this subject The research clearly indicates that attitudes toward stuttering vary according to geographical region. Less clear is whether mothers and fathers from geographically diverse backgrounds hold different attitudes toward stuttering and the extent to which parental status (being a parent, parent of a child who stutters or nonparent) affects attitudes toward stuttering. What this study adds This study's findings confirm that geographical differences do influence attitudes toward stuttering. Male parents and nonparents tend to have equal or more positive attitudes toward stuttering in Middle Eastern samples, whereas non-Middle Eastern female parents and nonparents tend to show hold more positive attitudes. What are the clinical implications of this work? In addition to being culturally sensitive when working with parents of children who stutter, clinicians should also consider that mothers and fathers may have some differences in attitudes and behaviours toward their child's stuttering. These differences should be considered when designing treatment plans. It should also be noted that, despite statistical significance, the effect sizes in this study were low, suggesting that further research as well as close collaboration with parents of children who stutter is warranted.

The application of neuronavigated rTMS of the supplementary motor area and rhythmic speech training for stuttering intervention.

BACKGROUND: Stuttering, a neurodevelopmental speech fluency disorder, is associated with intermittent disruptions of speech-motor control. Behavioural treatments for adults who stutter (AWS) concentrate on adopting speech patterns that enhance fluency, such as speaking rhythmically or prolonging speech sounds. However, maintaining these treatment benefits can be challenging. Neuroimaging studies suggest that supplementary motor area (SMA) which play a crucial role in speech initiation, planning and internal timing shows aberrant activation in speech production of AWS and may contribute to stuttering. Preliminary evidence suggests that brain stimulation may impact responsiveness to behavioural treatments. AIMS: The present study aims to investigate whether excitatory repetitive transcranial magnetic stimulation (rTMS) of the SMA and rhythmic speech can consistently reduce stuttering severity across various measures. METHODS AND PROCEDURES: Ten self-identified Cantonese-speaking AWS participated in this double-blinded, sham-controlled clinical trial study (NCT05472181). The participants underwent 10 sessions of rhythmic speech training across two phases, combined with either neuronavigated rTMS or sham, with a 2-week washout period between phases. The stuttering severity was assessed through various outcome measures, including the percentage of syllables stuttered, self-perceived stuttering severity, and the brief version of Unhelpful Thoughts and Beliefs About Stuttering before and after each treatment phase. OUTCOMES AND RESULTS: Results demonstrated improved speech fluency in various speaking contexts, with no significant difference between rTMS and sham conditions immediately and 1 week post-treatment. Notably, rTMS specifically led to less stuttering in tongue twister production (d = -0.70). Both treatment conditions effectively reduced self-perceived stuttering severity and negative thoughts and beliefs about stuttering. CONCLUSIONS AND IMPLICATIONS: The findings of this study indicate that stimulating the SMA reduced stuttering, only in the production of tongue twisters that may require greater motor control and coordination. Furthermore, it indicates that rhythmic speech might help alleviate negative beliefs and anxiety related to stuttering. This research contributes to our understanding of neuromodulation in stuttering treatment and the role of the SMA in speech motor control and emphasises the need for more research on the potential benefits and limitations of applying rTMS in this condition. WHAT THIS PAPER ADDS: What is already known on the subject Behavioural treatments for adults who stutter concentrate on adopting speech patterns that enhance fluency, such as speaking rhythmically or prolonging speech sounds. However, maintaining these treatment benefits can be challenging. Neuroimaging studies indicate that aberrant neural activation in speech production regions, like the supplementary motor area (SMA), is involved in stuttering. The SMA plays a crucial role in initiating, planning, and sequencing motor behaviours. Preliminary evidence suggests that brain stimulation (e.g., transcranial direct current stimulation or transcranial magnetic stimulation) may impact responsiveness to behavioural treatments. What this paper adds to existing knowledge There is limited knowledge regarding the potential effects of stimulating the SMA to enhance speech fluency in people who stutter. Existing research primarily consists of single case studies that lack proper control conditions or involve only a single stimulation session. Due to their limited scope and power, these studies may not provide sufficient evidence. The current study expands upon existing research by investigating whether multiple sessions of repetitive transcranial magnetic stimulation over the SMA, combined with rhythmic speech, improve speech fluency in adults who stutter. Furthermore, it addresses the limitations of brain stimulation methods and proposes directions for future research. What are the potential or actual clinical implications of this work? This study implies that the stimulation of SMA reduced stuttering only in speaking contexts that may require greater motor control and coordination such as tongue twisters. Additionally, the research suggests that using rhythmic speech could potentially alleviate negative beliefs and anxiety associated with stuttering.

Exploring participatory health research and its application to speech and language therapy research practices.

BACKGROUND: The role of participatory health research (PHR) is increasingly acknowledged by funding bodies, researchers and civil society globally; however, it continues to be under-represented in the speech and language therapy (SLT) research literature. This collaborative research approach is associated with the increased application of research evidence, and the generation of positive impacts in practice, policy, health systems and society. AIMS: To increase researchers' and other participatory partners' understanding of PHR, and to demonstrate its applicability to research in the SLT field. METHODS & PROCEDURES: This aim is achieved through a discussion on PHR, its principles, benefits and challenges, and the evaluation of its impact. A recently developed evaluation framework to support the implementation of best engagement practices is examined, and recommendations for how this framework can be used to plan and evaluate engagement in participatory stuttering research is presented. MAIN CONTRIBUTION: This paper serves as an important conversation on the value of PHR to SLT research, and presents guidance to support its increased implementation in this research field. CONCLUSIONS & IMPLICATIONS: Conclusions & Implications: PHR remains an under-represented research approach in the SLT literature, despite increasing evidence demonstrating its effectiveness and value. It offers a potential solution to the research-practice gap, and challenges the ongoing research hierarchies by democrating the process of knowledge production. WHAT THIS PAPER ADDS: What is already known on this subject PHR is increasingly attracting the attention of funders, researchers and decision-makers due to a growing body of evidence in support of this collaborative research approach. Despite its potential to bridge the research-practice gap, PHR remains significantly under-represented in the SLT research literature. What this paper adds to the existing knowledge This paper discusses the principles, benefits, challenges and impact evaluation of PHR. A recently developed evaluation framework for supporting the implementation of best engagement practices is examined. A demonstration of how this framework can be used to plan and evaluate engagement in participatory stuttering research is presented. What are the potential or actual clinical implications of this work? Speech and language therapists play a key role in PHR, as co-researchers contributing essential context-based knowledge. It is therefore imperative that they understand the principles and practices of this approach in order to maximize their input in future participatory partnerships.

Behind the mask: Stuttering, anxiety, and communication dynamics in the era of COVID-19.

BACKGROUND: While wearing masks during the pandemic poses communication and social challenges for people in everyday life, those with social anxiety might find them plausible, aligning with contemporary cognitive theories. Social anxiety involves fearing negative assessments and holding a negative self-image. Concealing anxiety symptoms during mask use may contribute to a more positive self-perception. AIMS: Given that up to 60% of adults seeking stuttering treatment also meet criteria for social anxiety disorder, this study aims to investigate the complex relationship between communication freedom, self-perceived stuttering and anxiety in adults who stutter (AWS). The unique context of mandatory mask-wearing during the pandemic provides an opportunity to explore these dynamics and understand the conflicting relationships between stuttering, anxiety-related safety behaviours and the need for open communication in AWS. METHODS AND PROCEDURES: Twenty AWS participated in interviews, responding to open-ended questions to elucidate their affective, cognitive and behavioural experiences while wearing masks during the COVID-19 pandemic. Thematic analysis was used to identify the emerging themes and subthemes based on information-rich quotes, employing a six-phase recursive process. Various speech and anxiety-related measures were used to describe the characteristics of the study participants. OUTCOMES AND RESULTS: Three main themes and sub-themes emerged. The first theme highlights communication challenges for AWS wearing masks, impacting verbal and nonverbal interactions. The second theme reveals AWS wearing masks to conceal stuttering cues, experiencing reduced stress. The third theme indicates that, despite the comfort in concealment, most AWS prefer speaking freely without a face mask. CONCLUSIONS AND IMPLICATIONS: The conflict between the desire for authentic, fluent communication and the ease of hiding stuttering symptoms poses a major dilemma for AWS. According to the results of this study, most adults who stutter prioritize open communication. However, there were some individual differences. A major factor influencing their decision was their fear of negative evaluation. WHAT THIS PAPER ADDS: What is already known on the subject The prevalence of social anxiety is higher among adults who stutter (AWS), possibly stemming from their prior negative experiences with stuttering. In response, AWS may adopt adaptive or maladaptive coping behaviours to manage stuttering and mitigate fears of negative evaluation. Maladaptive strategies, like avoiding certain communication situations, can diminish their satisfaction with everyday speaking situations. What this study adds This study leveraged the mask-wearing mandate during the pandemic to explore the intricate relationship between anxiety-related symptoms and communication. While some participants saw masks as a plausible means to conceal stuttering and anxiety, most preferred open communication without the challenges posed by masks. Our findings offer additional support for the varied emotional, cognitive and behavioural responses that AWS may display in response to changes in daily life, emphasizing the individual differences within this population and highlighting that stuttering goes beyond observable speech dysfluencies. What are the clinical implications of this work? Our study underscores the need for comprehensive therapeutic interventions addressing both the physical and cognitive-emotional aspects of stuttering in AWS. Recognizing the role of safety behaviours and self-focused attention emphasizes the importance of an integrated approach, enhancing communication efficacy and social well-being for AWS. Addressing speech fluency alone, without considering pertinent cognitive-emotional factors, falls short in providing adequate stuttering treatment.

Exploring the impact of stuttering simulation-based learning and personality traits on clinical self-efficacy and professional interest among speech-language pathology students.

BACKGROUND: Research suggests that participating in a stuttering simulation-based learning (SBL) program could help speech-language pathology (SLP) students feel more at ease, less nervous and more capable while interacting with people who stutter. Personality traits may influence SLP students' self-efficacy beliefs as well as their level of interest in working with clients who stutter. In particular, we suggest that the combination of low neuroticism and high extraversion, previously linked with a more outgoing, emotionally stable and social personality, may enhance self-efficacy. AIMS: To examine the impact of participating in a stuttering SBL program on clinical self-efficacy (CSE) in managing stuttering therapy among SLP students, as well as its influence on their interest in working with fluency disorders and their associations with personality dimensions. The study also evaluated satisfaction with the SBL experience. METHODS & PROCEDURES: SLP students (n = 49) underwent a fluency disorders academic course, self-reported on CSE, and had an interest in working in the field of stuttering and NEO-Five-Factor Inventory (NEO-FFI). Post-stuttering SBL program participation, CSE and level of interest in practice of stuttering were reassessed. Satisfaction with the simulation was also gauged. OUTCOMES & RESULTS: Students interested in working with fluency disorders scored lower in neuroticism and higher in extraversion than their uninterested counterparts. Before the SBL activity, interest ratings were negatively correlated with neuroticism and positively correlated with extraversion. Pre-SBL neuroticism was negatively correlated with CSE. Following the SBL activity, increased CSE and interest in working with fluency disorders were evident, indicating robust and medium effects of the simulation on those indices, respectively. Post-SBL neuroticism was also negatively correlated with CSE. Overall, participants reported high satisfaction with the SBL experience. CONCLUSIONS & IMPLICATIONS: The study suggests SBL is an effective tool for enhancing motivation to work with fluency disorders. Consideration of personality traits and professional interests in designing educational interventions for SLP students, along with tailoring approaches to individual differences, may enhance learning outcomes. The study also highlights the need to differentiate between CSE and objectively assessed clinical competence and the fact that professional development is influenced by various factors. Nonetheless, the positive correlations between personality traits, CSE and satisfaction emphasize the potential of SBL programs in shaping not only clinical skills but also the attitudes and preferences of future SLPs. WHAT THIS PAPER ADDS: What is already known on this subject SLPs in the field of stuttering therapy reportedly experience low levels of comfort and professional confidence, possibly due to insufficient clinical experience. According to earlier research, taking part in SBL programs may elevate the CSE of SLP students and help them feel more confident about treating people with stuttering. What this study adds to the existing knowledge In addition to showing the beneficial effects of an SBL activity on SLP students' self-efficacy and interest in working in stuttering therapy, our research shows a significant relationship between personality traits and CSE. Specifically, the combination of high extraversion and low neuroticism was found to be associated with higher CSE and higher levels of satisfaction from the SBL. What are the potential or actual clinical implications of this work? The study shows that SBL is an effective tool for enhancing motivation to work with fluency disorders. Overall, students who exhibit high extraversion and low neuroticism show higher levels of CSE, greater motivation in stuttering treatment, and higher levels of SBL stratification. Development of future SBL activities and other educational interventions should take into consideration such personality traits, to enhance learning outcomes.

Identification of the Biomechanical Response of the Muscles That Contract the Most during Disfluencies in Stuttered Speech.

Stuttering, affecting approximately 1% of the global population, is a complex speech disorder significantly impacting individuals' quality of life. Prior studies using electromyography (EMG) to examine orofacial muscle activity in stuttering have presented mixed results, highlighting the variability in neuromuscular responses during stuttering episodes. Fifty-five participants with stuttering and 30 individuals without stuttering, aged between 18 and 40, participated in the study. EMG signals from five facial and cervical muscles were recorded during speech tasks and analyzed for mean amplitude and frequency activity in the 5-15 Hz range to identify significant differences. Upon analysis of the 5-15 Hz frequency range, a higher average amplitude was observed in the zygomaticus major muscle for participants while stuttering (p < 0.05). Additionally, when assessing the overall EMG signal amplitude, a higher average amplitude was observed in samples obtained from disfluencies in participants who did not stutter, particularly in the depressor anguli oris muscle (p < 0.05). Significant differences in muscle activity were observed between the two groups, particularly in the depressor anguli oris and zygomaticus major muscles. These results suggest that the underlying neuromuscular mechanisms of stuttering might involve subtle aspects of timing and coordination in muscle activation. Therefore, these findings may contribute to the field of biosensors by providing valuable perspectives on neuromuscular mechanisms and the relevance of electromyography in stuttering research. Further research in this area has the potential to advance the development of biosensor technology for language-related applications and therapeutic interventions in stuttering.

Adaptation and Validation of Overall Assessment of the Speaker's Experience of Stuttering for Adults in Kannada (OASES-A-K).

INTRODUCTION: Psychosocial aspects of stuttering may affect the quality of life of a person who stutters (PWS). Further, the social stigma and experiences of PWS may vary globally. The WHO-ICF guidelines recommend quality of life as an essential component in the assessment of individuals who stutter. However, the availability of linguistically and culturally appropriate tools is often a challenge. Thus, the current study adapted and validated the OASES-A for Kannada-speaking adults who stutter. METHOD: The original English version of OASES-A was adapted to Kannada using a standard reverse translation process. The adapted version was administered on 51 Kannada-speaking adults with very mild to very severe stuttering. The data were analyzed for item characteristics, reliability, and validity assessment. RESULTS: The results revealed floor and ceiling effects for six and two items, respectively. The mean overall impact score indicated a moderate impact of stuttering. Further, the impact score for section II was relatively higher when compared to the data from other countries. The reliability and validity analyses showed good internal consistency and test-retest reliability for OASES-A-K. CONCLUSION: The findings of the current research suggest that OASES-A-K is a sensitive and reliable tool to assess the impact of stuttering in Kannada-speaking PWS. The findings also highlight cross-cultural differences and the need for research in this direction.

Validation of the Persian Version of the Palin Parent Rating Scales.

INTRODUCTION: The Palin Parent Rating Scale (Palin PRS) is a structured questionnaire filled out by parents of children who stutter. It is designed to assess the effects of stuttering on both the children and their parents. The goal of this study was to translate the Palin PRS into Persian and to evaluate its validity and reliability for application in preschool children who stutter. METHODS: This research was conducted from August 2021 to December 2022, involving 139 parents of children who stutter. The parents completed the Palin PRS and provided their demographic data. Descriptive statistics were used to examine the floor and ceiling effects on all subscales of the Palin PRS. The internal consistency of the scale was assessed using Cronbach's alpha method, while the intraclass correlation coefficient (ICC) was calculated to determine its test-retest reliability. An exploratory factor analysis was also performed to clarify the factor structure of the scale. RESULTS: The exploratory factor analysis results were highly consistent with the factor structure found in the original version. No floor or ceiling effects were observed for the factors of the Palin PRS. The three factors of the Persian version of the Palin PRS (P-Palin PRS) showed good internal consistency (Cronbach's alpha >0.8) and excellent test-retest reliability (ICC >0.9). Additionally, normative scores were derived by converting raw scores into Stanine scores. CONCLUSION: The P-Palin PRS showed strong reliability, thereby establishing it as a suitable instrument for evaluating how parents perceive the effects of stuttering on their children and themselves. Further research may explore its application in diverse clinical settings and populations.

Attitudes of Malaysian Speech-Language Pathologists and Speech-Language Pathology Students toward Stuttering.

INTRODUCTION: Attitudes of speech-language pathologists (SLPs) toward stuttering play an important role in managing stuttering cases. Yet, such studies had not been studied in Malaysia, a country that is still developing the profession of speech-language pathology. This study aimed to explore the attitudes of Malaysian SLPs and speech-language pathology students toward stuttering. METHODS: A total of 50 SLPs and 67 speech-language pathology students completed the Clinician Attitudes Toward Stuttering (CATS) inventory. There were eight domains of attitudes toward stuttering: (a) etiology, (b) early intervention, (c) therapeutic efficacy, (d) personalities of people who stutter (PWS), (e) clinician expertise and roles, (f) teacher/counsellor roles and client/public reactions, (g) therapy strategies, and (h) parent attitudes. Descriptive data were presented, and multivariate analysis of variance was conducted to examine the effects of clinical certification on the eight domains of attitudes toward stuttering. RESULTS: Participants who possessed a clinical certification were more accepting toward the personalities of PWS and therapy strategies. On the other hand, participants without a clinical certification were more accepting toward clinician expertise and roles. CONCLUSIONS: Current curriculum and professional training should be reevaluated to remediate less accepting stereotypes held by SLPs and students toward PWS and to enhance essential skills such as counseling.

Awareness and Knowledge of Stuttering among Malaysian School-Aged Children: An Exploratory Study.

INTRODUCTION: Knowledge and awareness of stuttering are closely associated with attitudes toward stuttering. Few studies have been conducted on the knowledge and awareness of school-aged children, and none have been conducted in Malaysia. This study aimed to: (a) determine knowledge and awareness of stuttering among Malaysian school-aged children, and (b) determine whether there are differences between age group, gender, and people who stutter (PWS) exposure groups. METHODS: A cross-sectional study was conducted among 192 Malay school-aged children (mean age = 9.47, SD = 1.781) recruited via email and social media platforms. They completed a Malay version of the questionnaire devised by van Borsel et al. (1999) on various aspects of stuttering, including prevalence, onset, gender distribution, occurrence in different cultures, cause, treatment, intelligence, and heredity of stuttering. The χ2 test of independence was performed to compare the distributions of survey responses by age group, gender, and PWS exposure group. RESULTS: Around half of the school-aged children had met a person who stutters, but certain aspects of their knowledge were limited. Knowledge also differed according to age and gender. Girls were more knowledgeable about stuttering than boys. Regarding stuttering treatment, younger children had more positive attitudes than older children. Participants who did not know a PWS were more likely to consult their family doctor rather than a speech-language pathologist in relation to stuttering. CONCLUSION: Knowledge and awareness of stuttering among Malaysian school-aged children were limited. Findings of this study could be used to develop a stuttering awareness program specific to children to increase their knowledge and awareness about stuttering.

Self-reported musculoskeletal pain, headache, jaw pain and swallowing dysfunction in a sample of young Saudi adults who stutter.

Objectives: To report the prevalence of musculoskeletal pain, headache, jaw pain and difficulty in swallowing among people who stutter (PWS). METHODS: The cross-sectioal study was conducted from October 3, 2021, to March 21, 2022, after approval from the ethics review committee of King Khalid University, Abha, Saudi Arabia, and comprised adult people who stutter belonging to different regions of Saudi Arabia. They were divided into five groups based on stuttering severity as estimated by Stuttering Severity Instrument-4. Data was collected on musculoskeletal pain in different body areas using a questionnaire.. Data ws analysed using SPSS 22. RESULTS: Of the 101 Arabic-speaking subjects, 63(62.4%) were males and 38(37.6%) were females. The overall mean age was 27±7 years (range: 18-39 years). The largest group was of subjects with moderate severity of stuttering 31(30.6%); 21(68%) males and 10(32%) females. The increase in number of musculoskeletal pain locations was related to the severity of stuttering (p<0.05). The most common musculoskeletal pain sites were the lower back 31(31%), neck 26(26%) and shoulder 26(26%). Frequent headaches and difficulty chewing hard food due to jaw pain were reported by 49(49%) and 22(22%) participants, respectively (p<0.05). Swallowing difficulty was reported by 9(9%) participants (p>0.05). CONCLUSIONS: Widespread chronic musculoskeletal pain of low intensity was found to be common among people who stuttered, and the number of pain locations was positively related to stuttering severity.

Attention networks in multilingual adults who do and who do not stutter.

This study investigated whether multilinguals who stutter differ from multilinguals who do not stutter in terms of attention networks. Towards that end, it measured (a) performance differences in attention networks between multilinguals who stutter and those who do not stutter and (b) the correlation between stuttering characteristics and attention networks. Twenty-four multilingual Dutch-English speaking adults (20-46y), half of whom were diagnosed with stuttering, completed the Attentional Network Task (ANT) that evaluates the attention networks of alerting, orienting, and executive control. A language and social background questionnaire and a lexical decision task (LexTALE) assessed the participants' language proficiency. The Stuttering Severity Instrument 4th Ed. and the Brief Version of the Unhelpful Thoughts and Beliefs About Stuttering Scale were used to evaluate stuttering characteristics. The two groups did not differ in the ANT in terms of reaction time and error rate scores. Furthermore, no differences were observed in the three attention networks between the groups. Lastly, no correlation was found between stuttering characteristics and attention networks. The results suggest that the attention abilities of multilinguals who stutter do not differ from multilinguals who do not stutter.

Manifestation of speech disfluencies in preschool Cantonese-English speaking bilingual children.

Stuttering is characterised by disruptions in speech fluency that normally emerges between the ages of 2 to 5 when children start to formulate sentences. Current stuttering identification in children is largely based on speech disfluency criteria (>3% stuttering-like disfluencies, SLDs) developed for monolingual English-speaking children. Research in a Western language context shows that application of the criteria for monolingual to bilingual children may result in false positive diagnosis of stuttering. The applicability of these criteria to children speaking languages typologically distinct from English remains unclear. This preliminary study focused on bilingual Cantonese-English-speaking children, aiming to explore the manifestations of the speech disfluencies in Cantonese (a syllable-timed language) and English (a stress-timed language) while accounting for language dominance/proficiency and speaking task. Nineteen typically fluent Cantonese-English bilingual preschoolers were recruited for this study and their speech samples were collected across different speaking tasks (i.e. conversation and narration), and languages (i.e. Cantonese and English). The types and frequency of speech disfluencies were compared across both languages and the speaking tasks. The results showed that between 21-68% of children showed higher than 3% SLDs across different languages and speaking tasks. Linear mixed-effect analysis revealed that the prevalence of SLDs is higher in English (less dominant language) than Cantonese (more dominant language), and the prevalence is also higher in narration than conversation. These findings suggest the need for tailored stuttering identification criteria for bilingual children speaking diverse languages and emphasise the importance of considering language dominance/proficiency and speaking task when assessing stuttering in bilingual populations.

Syllable- and word-based measures of stuttering in speech samples of Turkish-speaking school-aged children.

Linguistic factors influence the likelihood of occurrence of stuttering instances on a certain word within an utterance. However, studies on the relationship between stuttering instances and linguistic factors of Turkish-speaking individuals are scarce. This study aimed to determine the syllable- and word-based measures of stuttering speech samples of Turkish-speaking school-aged children who stutter. Stuttering-like disfluencies (SLDs) and lexical categories were identified after transcription of 61 children's spontaneous speech samples (age range = 6-16). Syllable-, word- and utterance-level measures were employed. Syllable-based and word-based stuttering frequency findings were significantly different (p < .001); SLDs were more likely to occur at the utterance-initial (p < .001) and word-initial (p < .001) positions; content words were more likely to be stuttered and, there was a relation between the occurrence of SLDs and utterance length (p = .001). Since there is great variability between word-based and syllable-based measures, and SLDs tend to occur at word onsets, using word-based measures in Turkish would provide a measure of stuttering frequency that is comparable to the literature. Moreover, findings support that phrases requiring greater demands on utterance planning increase the possibility of occurrence of stuttering instances.

Korean listeners' identification and discrimination of lengthened /s/ as prolongations.

This study aimed to examine Korean listeners' judgement of sound duration as prolongation and the mode of perceiving prolongation, whether discrete or continuous. A total of 75 Korean undergraduate students listened to the Korean segment /s/, each of which was lengthened by 0-380 ms (ranging from the original 205 to 585 ms) in 20-ms increments. Then, the participants were asked to complete two different primary tasks: determine whether the sound was normal (0) or abnormal (1) and rate each version of the sound based on a rating of 1 to 100 (the closer to 100, the less fluent). The minimum duration for the Korean sound to be perceived as abnormally prolonged was calculated by analysing the receiver operating characteristic (ROC) curves using Youden's index. To examine whether listeners perceived durational variations for the fricative segment discretely or continuously, a curve was estimated using the best fitting regression model for the observed data with the highest adjusted R-squared value. The minimum duration identified as abnormal prolongation for the Korean lenis fricative /s/ was 375 ms, corresponding to 182.9% of the original, unaltered sound's length. The mode of perceiving durational variations for the segment was continuous (or gradient) rather than discrete. No gender difference was found in the minimum durational threshold and the mode of perceiving prolongation. The findings of this study were further discussed in relation to the existing body of research, and some clinical implications for the assessment of stuttering were also presented.

Hand Preference in Stuttering: Meta-Analyses.

Reduced hemispheric asymmetries, as well as their behavioral manifestation in the form of atypical handedness (i.e., non-right, left-, or mixed-handedness), are linked to neurodevelopmental disorders, such as autism spectrum disorder, and several psychiatric disorders, such as schizophrenia. One neurodevelopmental disorder that is associated with reduced hemispheric asymmetries, but for which findings on behavioral laterality are conflicting, is stuttering. Here, we report a series of meta-analyses of studies that report handedness (assessed as hand preference) levels in individuals who stutter (otherwise healthy) compared to controls. For this purpose, articles were identified via a search in PubMed, Scopus, and PsycInfo (13 June 2023). On the basis of k = 52 identified studies totaling n = 2590 individuals who stutter and n = 17,148 controls, five random effects meta-analyses were conducted: four using the odds ratio [left-handers (forced choice); left-handers (extreme); mixed-handers; non-right-handers vs. total)] and one using the standardized difference in means as the effect size. We did not find evidence of a left (extreme)- or mixed-handedness difference or a difference in mean handedness scores, but evidence did emerge, when it came to left-handedness (forced-choice) and (inconclusively for) non-right-handedness. Risk-of-bias analysis was not deemed necessary in the context of these meta-analyses. Differences in hand skill or strength of handedness could not be assessed as no pertinent studies were located. Severity of stuttering could not be used s a moderator, as too few studies broke down their data according to severity. Our findings do not allow for firm conclusions to be drawn on whether stuttering is associated with reduced hemispheric asymmetries, at least when it comes to their behavioral manifestation.