Perceptions of and beliefs about stuttering in the Hispanic/Latino community.

PURPOSE: The aim of this exploratory study was to investigate perceptions of people who stutter and beliefs about the causes and cures of stuttering within the Hispanic/Latino community. METHODS: Respondents who were 18 or older and of Hispanic/Latino origin were invited to respond to a 24-question online survey. Questions involved exploring familiarity with and beliefs regarding etiologies, treatment approaches, treatment providers, stereotypes, and perceptions of people who stutter. Data from 151 respondents were analyzed using descriptive statistics. RESULTS: Results revealed that the most commonly held beliefs regarding the causes of stuttering were being "born with it", an "emotional disturbance or trauma", a "brain disorder", and/ or a "sensory impairment". The most frequently cited beliefs regarding treating stuttering were "therapy", "rehabilitation", and "tell them to slow down". Over 75 % of respondents believed that "speech therapists" can cure or treat stuttering. Respondents' perceptions of people who stutter are that they are generally "nervous" and "shy". CONCLUSIONS: Common beliefs and perceptions relative to stuttering were identified in the Hispanic/Latino community. The beliefs one holds about the cause of stuttering as well as their negative perceptions of stutterers may contribute to the continued stigmatization of people who stutter. Implications are discussed regarding the need for culturally appropriate education for individuals who stutter, their families, and the general public.

Corrigendum: Identifying stuttering in Arabic speakers who stutter: development of a non-word repetition task and preliminary results.

[This corrects the article DOI: 10.3389/fped.2022.750126.].

Treatment of obstructive sleep apnea relieves stuttering priapism in patient with sickle cell disease: a case report.

Background: Stuttering priapism is recurrent, self-limited episodes of sustained penile erection and is common in patients with sickle cell disease (SCD). Prevention of stuttering priapism is important to avoid progression to episodes of ischemic priapism which can cause erectile dysfunction. Priapism has been shown to be associated with increased nocturnal hypoxemia in patients with SCD. Case Description: A 43-year-old male with nocturnal episodes of stuttering priapism that was refractory to treatment with multiple medications was found to have obstructive sleep apnea (OSA). Following treatment of this condition with a continuous positive airway pressure (CPAP), the patient had immediate symptom relief and has had three months without an episode of priapism. Conclusions: OSA should be considered as an underlying cause of nocturnal stuttering priapism in patients with SCD, particularly in patients who present with stuttering priapism later in life or patients who present strictly with nocturnal episodes. Appropriate management of OSA can significantly decrease the incidence of stuttering priapism in patients with SCD.

Corrigendum: Stuttering in individuals with Down syndrome: a systematic review of earlier research.

[This corrects the article DOI: 10.3389/fpsyg.2023.1176743.].

Explicit and implicit cognitive processes of the public towards people who stutter.

PURPOSE: The Public Opinion Survey of Human Attributes - Stuttering (POSHA-S, St. Louis, 2013) was developed as a standard measure of public attitudes about people who stutter. As with any survey-based methods, threats to validity may occur because of social desirability bias. Using computer mouse-tracking, we were interested in observing changes in cognition that are manifested in intentionality through action by evaluating underlying cognitive processes that drive social judgments of people who stutter. METHODS: Twenty-two women, 1 non-binary person, and 47 men reported using a computer mouse to complete an online, remote, and modified version of the POSHA-S. Responses were categorized as correct/helpful or incorrect/unhelpful relative to each component of the POSHA-S and were used as measures of explicit cognitive processes. Computer-mouse trajectory metrics, including area under the curve (AUC) and reaction time (RT), were used to measure implicit cognitive processes. RESULTS: Although participants' explicit responses were significantly more likely to be correct/helpful than incorrect/unhelpful, with endorsement of correct/helpful prompts 77 % of the time, participants also endorsed incorrect/unhelpful prompts more than half (i.e., 52 %) of the time. Familiarity with people who stutter was associated with disagreeing with incorrect/unhelpful prompts. As indicated by greater AUC, participants exhibited significantly more implicit cognitive processes indicating competition when responding "disagree" compared to "agree", regardless of whether the prompts were correct/helpful or incorrect/unhelpful. Similarly, participants took significantly longer to respond to prompts with "disagree" rather than "agree". CONCLUSION: The findings of this study offer evidence of participants reporting cognitive processes that are overall more correct/helpful than incorrect/unhelpful, in their explicit responses to the dichotomous response tasks of the POSHA-S. However, these findings are tempered by evidence of a tendency to agree with statements in the measure and suggest the need for further research to increase understanding of how to measure and improve explicit and implicit cognitive processes related to people who stutter.

Psychedelics in developmental stuttering to modulate brain functioning: a new therapeutic perspective?

Developmental stuttering (DS) is a neurodevelopmental speech-motor disorder characterized by symptoms such as blocks, repetitions, and prolongations. Persistent DS often has a significant negative impact on quality of life, and interventions for it have limited efficacy. Herein, we briefly review existing research on the neurophysiological underpinnings of DS -specifically, brain metabolic and default mode/social-cognitive networks (DMN/SCN) anomalies- arguing that psychedelic compounds might be considered and investigated (e.g., in randomized clinical trials) for treatment of DS. The neural background of DS is likely to be heterogeneous, and some contribution from genetically determinants of metabolic deficiencies in the basal ganglia and speech-motor cortical regions are thought to play a role in appearance of DS symptoms, which possibly results in a cascade of events contributing to impairments in speech-motor execution. In persistent DS, the difficulties of speech are often linked to a series of associated aspects such as social anxiety and social avoidance. In this context, the SCN and DMN (also influencing a series of fronto-parietal, somato-motor, and attentional networks) may have a role in worsening dysfluencies. Interestingly, brain metabolism and SCN/DMN connectivity can be modified by psychedelics, which have been shown to improve clinical evidence of some psychiatric conditions (e.g., depression, post-traumatic stress disorder, etc.) associated with psychological constructs such as rumination and social anxiety, which also tend to be present in persistent DS. To date, while there have been no controlled trials on the effects of psychedelics in DS, anecdotal evidence suggests that these agents may have beneficial effects on stuttering and its associated characteristics. We suggest that psychedelics warrant investigation in DS.

Mitigating stuttering self-stigma: How do we start and where do we go? Using a Participative Concept Mapping Approach to develop a local framework of principles.

PURPOSE: This study aims to create a stigma reduction framework for stuttering in the local context of Québec, Canada using the Participative Concept Mapping Approach (PCMA), focusing on both self and societal stigma. METHOD: Employing a mixed-methods approach, this study engaged 17 experts-people who stutter, clinicians and health innovation specialists-in PCMA workshops. Via diverse steps, including generation, sorting and rating of ideas in response to the focus prompt, "To effectively address stuttering (self-)stigma, an intervention should…" these sessions led to a framework depicted in visual maps, then refined into actionable principles through qualitative analysis. Mixed-methods data analysis used the open-source R-CMap software to generate visual maps illustrating the relationships among ideas as well as importance and feasibility ratings. RESULTS: The collaborative workshops identified 95 ideas in response to the focus prompt, reunited in 7 clusters, evolving into 16 principles to mitigate stuttering stigma and self-stigma. At the therapy level, these principles emphasize personalized therapy, thorough assessments, stigma-free therapeutic environment, empowerment, and the importance of group inclusivity and educating the relational circles. Societally, they advocate for initiatives such as improved educational outreach, empathy enhancement, and better representation. This dual approach targets individual experiences and societal views on stuttering, stressing the need for an all-encompassing intervention framework. CONCLUSION: The findings demonstrate PCMA's usefulness in crafting local, culturally sensitive, tailored interventions for stigma reduction. The study emphasizes the necessity of holistic approaches that address individual experiences and societal perceptions, offering a model to conduct similar exercises in diverse local settings.

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.

Stutterers' experiences on classic psychedelics: A preliminary self-report study.

Stuttering poses challenges to social, occupational, and educational aspects of life. Traditional behavioral therapies can be helpful but effects are often limited. Pharmaceutical treatments have been explored but there are no FDA-approved treatments for stuttering. Interest has grown in the potential use of classic psychedelics, including psilocybin and LSD, which have shown effectiveness in treating disorders with similar symptoms (e.g., anxiety, depression, PTSD). The potential effects of psychedelics on stuttering have not been explored. We conducted a preliminary investigation of self-identified stutterers who report their experiences taking classic psychedelics on the online messaging forum, Reddit. We qualitatively analyzed 114 publicly available posts, extracting meaningful units and assigning descriptor codes inductively. We then deductively organized responses into an established framework of psychedelics which includes behavioral, emotional, cognitive, belief-based, and social effects. These effects were subsequently grouped under organizing themes (positive, negative, neutral). Descriptive statistics revealed that the majority of users (74.0%) reported positive overall short-term effects particularly related to behavioral and emotional change (e.g., reduced stuttering and anxiety), but negative (9.6%), mixed (positive and negative; 4.8%), and neutral overall experiences (11.6%) were also reported. The results support the possibility that psychedelics may impact stuttering, but caution must be applied in their interpretation given the entirely uncontrolled research setting and potential adverse health effects of psychedelics as reported elsewhere. While these results do not encourage the use of psychedelics by stutterers, they suggest that future work could examine the impact of psychedelics on stuttering under supervised and in clinically controlled settings.

Allergies, asthma, and sleep problems in adults who stutter.

PURPOSE: Previous studies have suggested that allergies, asthma, and sleep problems are prevalent in those who stutter. This study analyzed similar data for a broad age group of adults who stutter (AWS). METHOD: Data from the 2012 National Health Interview Survey were analyzed. Adults from 18 to 60 + years of age reported a) to have stuttered, b) to have had any allergy, asthma, or acid reflux, c) to have had insomnia/trouble sleeping and daytime negative consequences, and d) average sleeping hours per day in the past 12 months. RESULTS: The sample included 320 AWS and 33,043 controls. AWS were at greater odds of respiratory, food, and skin allergies (OR = 2.38, 2.36, and 2.09, respectively), as well as asthma and acid reflux (OR = 2.30 and 2.01, respectively) than controls. AWS were at greater odds of insomnia/trouble sleeping, oversleeping, excessive sleepiness, and fatigue than controls (OR = 2.11, 1.71, 2.67, and 1.81, respectively). The subgroup of AWS with no allergy, asthma, and acid reflux were also at greater odds of insomnia/trouble sleeping and excessive sleepiness than controls (OR = 2.13 and 3.11, respectively). Differences were found in specific age groups: younger/middle-aged AWS reported more allergies, asthma, and acid reflux than controls, while older AWS did not; younger/middle-aged AWS reported more insomnia/trouble sleeping than controls, while older AWS reported more oversleeping. CONCLUSIONS: Findings on younger and middle-aged AWS are similar to previous ones on children and adolescents who stutter. Differences regarding younger/middle-aged and older AWS could be consequence of environmental variables.

Reactive Inhibitory Control Precedes Overt Stuttering Events.

Research points to neurofunctional differences underlying fluent speech between stutterers and non-stutterers. Considerably less work has focused on processes that underlie stuttered vs. fluent speech. Additionally, most of this research has focused on speech motor processes despite contributions from cognitive processes prior to the onset of stuttered speech. We used MEG to test the hypothesis that reactive inhibitory control is triggered prior to stuttered speech. Twenty-nine stutterers completed a delayed-response task that featured a cue (prior to a go cue) signaling the imminent requirement to produce a word that was either stuttered or fluent. Consistent with our hypothesis, we observed increased beta power likely emanating from the right pre-supplementary motor area (R-preSMA)-an area implicated in reactive inhibitory control-in response to the cue preceding stuttered vs. fluent productions. Beta power differences between stuttered and fluent trials correlated with stuttering severity and participants' percentage of trials stuttered increased exponentially with beta power in the R-preSMA. Trial-by-trial beta power modulations in the R-preSMA following the cue predicted whether a trial would be stuttered or fluent. Stuttered trials were also associated with delayed speech onset suggesting an overall slowing or freezing of the speech motor system that may be a consequence of inhibitory control. Post-hoc analyses revealed that independently generated anticipated words were associated with greater beta power and more stuttering than researcher-assisted anticipated words, pointing to a relationship between self-perceived likelihood of stuttering (i.e., anticipation) and inhibitory control. This work offers a neurocognitive account of stuttering by characterizing cognitive processes that precede overt stuttering events.

Validity and utility of the Japanese version of the brief unhelpful thoughts and beliefs about stuttering scale: UTBAS-6-J.

Do adults who stutter have abnormally high social anxiety? Is it related to maladaptive cognition? As these are persistent, unresolved questions in stuttering research, it behooves clinicians to at least assess and attempt to identify social anxiety in patients who stutter and its basis before decisions are made about stuttering treatment. The Unhelpful Thoughts and Beliefs About Stuttering (UTBAS) scale is a self-administered questionnaire that measures the degree of non-adaptive cognition in people who stutter (PWS) due to social anxiety. The 66-item UTBAS is time-consuming to complete, prompting the development of a shorter 6-item version, the UTBAS-6, which is in English. Here, we aimed to assess some psychometric properties of the Japanese version of the UTBAS-6, the UTBAS-6-J, which has not been done to date. In 56 adult patients (mean 32.6 ± 11.1 years) who stutter, we quantified the reliability, the internal consistency, and the concurrent validity of the UTBAS-6-J. Along with the UTBAS-6-J, patients also were administered the Overall Assessment of the Speaker's Experience of Stuttering - Japanese version (OASES-A-J), the Modified Erickson Communication Attitude Scale - Japanese version (S-24-J), and the Liebowitz Social Anxiety Scale - Japanese version (LSAS-J). Cronbach's alpha for UTBAS-6-J total scores was 0.974, indicating excellent internal consistency. UTBAS-6-J scores were significantly correlated with scores on the OASES-A-J, the S-24-J, and the LSAS-J (all p < 0.005). Concurrent validity of the UTBAS-6-J with these three questionnaires was confirmed. The UTBAS-6-J has good internal consistency and concurrent validity, which will aid clinical decision-making about stuttering treatments.

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.

Subtle Patterns of Altered Responsiveness to Delayed Auditory Feedback during Finger Tapping in People Who Stutter.

Differences in sensorimotor integration mechanisms have been observed between people who stutter (PWS) and controls who do not. Delayed auditory feedback (DAF) introduces timing discrepancies between perception and action, disrupting sequence production in verbal and non-verbal domains. While DAF consistently enhances speech fluency in PWS, its impact on non-verbal sensorimotor synchronization abilities remains unexplored. A total of 11 PWS and 13 matched controls completed five tasks: (1) unpaced tapping; (2) synchronization-continuation task (SCT) without auditory feedback; (3) SCT with DAF, with instruction either to align the sound in time with the metronome; or (4) to ignore the sound and align their physical tap to the metronome. Additionally, we measured participants' sensitivity to detecting delayed feedback using a (5) delay discrimination task. Results showed that DAF significantly affected performance in controls as a function of delay duration, despite being irrelevant to the task. Conversely, PWS performance remained stable across delays. When auditory feedback was absent, no differences were found between PWS and controls. Moreover, PWS were less able to detect delays in speech and tapping tasks. These findings show subtle differences in non-verbal sensorimotor performance between PWS and controls, specifically when action-perception loops are disrupted by delays, contributing to models of sensorimotor integration in stuttering.

The experience of stuttering in everyday life among adults who stutter: The impact of trait social anxiety and the social situations.

PURPOSE: The purpose of this study was to investigate the emotional and stuttering experience of adults who stutter (AWS) in everyday life, and how that experience may be shaped by personal (i.e., trait social anxiety) and situational factors (i.e., social partner reaction, communication channel type, social closeness, stuttering knowledge). METHOD: AWS completed ecological momentary assessments on their smartphones multiple times a day for up to three weeks. Data (n = 62) were analyzed with multilevel models to determine how situational factors and trait social anxiety influence the Negative Affect (NA), Positive Affect (PA), and self-reported stuttering severity of AWS. RESULTS: Results indicated that having high (vs. low) trait social anxiety was associated with a tendency to experience high NA, low PA, and high self-reported stuttering severity among AWS. A range of situational factors significantly influenced the within-person variation of NA, PA, and self-reported stuttering severity in everyday life. In addition, interacting with distant social partners relative to being alone heightened NA, and the effect was more prominent among AWS with high (vs. low) trait social anxiety. CONCLUSIONS: Overall, the findings suggest that the variation of affects and stuttering severity among AWS can be partly accounted for by factors from both the situational and personal levels. Clinicians should be aware of the low PA experienced by AWS who have high (vs low) trait social anxiety in everyday life.

Development and validation of a research version of the Overall Assessment of the Speaker's Experience of Stuttering- Adult (OASES-A-R).

BACKGROUND: The Overall Assessment of the Speaker's Experience of Stuttering for Adults (OASES-A; Yaruss & Quesal, 2016) is a widely used measurement tool designed to evaluate the adverse impact associated with stuttering. Items examine general perceptions of stuttering, personal reactions to stuttering, functional communication difficulties, and consequences for quality of life. This paper presents a shortened research version of the OASES-A response form (OASES-A-R) that can be used by researchers in scientific studies involving adults who stutter that reflect the Section and Total Scores of the original OASES-A using fewer items. METHOD: Previously collected OASES-A data (N = 315) were analyzed via graded response modeling to identify discrimination values of each OASES-A item in measuring each OASES-A Section Total Score. Items with the highest discrimination and items judged by expert clinicians to be more important in measuring adverse impact (N = 27) were used to create a shortened OASES-A-R. The shortened OASES-A-R response form was then validated and compared to the full OASES-A response form in an independent sample (N = 156). RESULTS: The shortened 25-item OASES-A-R response form demonstrated very high and positive correlations with the full OASES-A response form. Similarly, each OASES-A-R Section demonstrated high internal reliability coefficients similar to those of the OASES-A. DISCUSSION: The resulting 25-item OASES-A-R response form provides a reflection of the speaker's experience of stuttering as measured by the original 100-item OASES-A that is suitable for use in certain research studies of adults who stutter. Clinical use is not recommended, as the full OASES-A provides additional insights about a client's experience of stuttering that are necessary for effective treatment planning and intervention.

Evidence for planning and motor subtypes of stuttering based on resting state functional connectivity.

We tested the hypothesis, generated from the Gradient Order Directions Into Velocities of Articulators (GODIVA) model, that adults who stutter (AWS) may comprise subtypes based on differing connectivity within the cortico-basal ganglia planning or motor loop. Resting state functional connectivity from 91 AWS and 79 controls was measured for all GODIVA model connections. Based on a principal components analysis, two connections accounted for most of the connectivity variability in AWS: left thalamus - left posterior inferior frontal sulcus (planning loop component) and left supplementary motor area - left ventral premotor cortex (motor loop component). A k-means clustering algorithm using the two connections revealed three clusters of AWS. Cluster 1 was significantly different from controls in both connections; Cluster 2 was significantly different in only the planning loop; and Cluster 3 was significantly different in only the motor loop. These findings suggest the presence of planning and motor subtypes of stuttering.

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.

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.