A speech fluency brain network derived from gliomas.

The brain network of speech fluency has not yet been investigated via a study with a large and homogenous sample. This study analysed multimodal imaging data from 115 patients with low-grade glioma to explore the brain network of speech fluency. We applied voxel-based lesion-symptom mapping to identify domain-specific regions and white matter pathways associated with speech fluency. Direct cortical stimulation validated the domain-specific regions intra-operatively. We then performed connectivity-behaviour analysis with the aim of identifying connections that significantly correlated with speech fluency. Voxel-based lesion-symptom mapping analysis showed that damage to domain-specific regions (the middle frontal gyrus, the precentral gyrus, the orbital part of inferior frontal gyrus and the insula) and white matter pathways (corticospinal fasciculus, internal capsule, arcuate fasciculus, uncinate fasciculus, frontal aslant tract) are associated with reduced speech fluency. Furthermore, we identified connections emanating from these domain-specific regions that exhibited significant correlations with speech fluency. These findings illuminate the interaction between domain-specific regions and 17 domain-general regions-encompassing the superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus and rolandic operculum, superior temporal gyrus, temporal pole, inferior temporal pole, middle cingulate gyrus, supramarginal gyrus, fusiform gyrus, inferior parietal lobe, as well as subcortical structures such as thalamus-implicating their collective role in supporting fluent speech. Our detailed mapping of the speech fluency network offers a strategic foundation for clinicians to safeguard language function during the surgical intervention for brain tumours.

Could linguistic and cognitive factors, degree of autistic traits and sex predict speech disfluencies in autistic young adults and controls?

This study aimed to evaluate the effect of linguistic complexity and individual background variables (i.e. linguistic and cognitive abilities, degree of autistic traits, and sex) on speech disfluencies in autistic young adults and controls. Thirty-two 19- to 33-year-old autistic adults and 35 controls participated in this study. The frequency of disfluencies and stuttering severity were evaluated based on a narrative speech task. Linguistic complexity was assessed by evaluating the syntactic structures of the narratives. Cognitive and linguistic abilities were assessed using the General Ability Index (GAI), Verbal Comprehension Index (VCI) and Perceptual Reasoning Index (PRI) from the Wechsler Adult Intelligence Scale IV. Autistic traits were measured using the Autism Spectrum Quotient (AQ). Multiple-linear regression analyses (syntactic complexity, GAI, AQ, sex, and group status as predictors) showed that (a) syntactic complexity predicted total and stuttering-like disfluencies and stuttering severity, (b) GAI predicted typical disfluencies, and (c) sex predicted total, typical, and stuttering-like disfluencies. Additional correlation analyses revealed negative association between PRI and disfluencies in the control group but not in the autistic group. No connection was found between AQ and disfluencies. It seems that while some connections between disfluencies and individual cognitive features were found, some of the possible contributing factors for greater speech disfluency might differ between autistic and typical speakers.

Disfluency across the lifespan: an individual differences investigation.

This study had two research objectives. The first was to examine age-related differences in the fluency of speech outputs, as prior research contains conflicting findings concerning whether older adults produce more disfluency than younger adults. The second was to examine cognitive individual differences, and their relationship with the production of disfluency. One hundred and fifty-four adults completed a story re-telling task, and a battery of cognitive measures. Results showed that younger adults produced more um's and fewer repetitions. For individual differences, results showed that inhibition and set shifting were related to the production of repetitions, and inhibition and working memory were related to uh production. Our results provide clarification about mixed findings with respect age and disfluency production. The individual differences provide clarification on theoretical arguments for disfluent speech in aging (e.g. Inhibition Deficit Hypothesis), and also sheds light on the role of executive functions in models of language production.

Speech Fluency Production and Perception in L1 (Slovak) and L2 (English) Read Speech.

Research on fluency in native (L1) and non-native (L2) speech production and perception helps us understand how individual L1 speaking style might affect perceived L2 fluency and how this relationship might be reflected in L1 versus L2 oral assessment. While the relationship between production and perception of fluency in spontaneous speech has been studied, the information provided by reading has been overlooked. We argue that reading provides a direct and controlled way to assess language proficiency that might complement information gained from spontaneous speaking. This work analyzes the relationship between speech fluency production and perception in passages of L1 (Slovak) and L2 (English) read by 57 undergraduate Slovak students of English and rated for fluency by 15 English teachers who are Slovak natives. We compare acoustic production measures between L1 and L2 and analyze how their effect on perceived fluency differs for the two languages. Our main finding is that the articulation rate, the overall number of pauses, and the number of between-clause and mid-clause pauses predict ratings differently in L1 Slovak versus L2 English. The speech rate and durations of pauses predict ratings similarly in both languages. The contribution of our results to understanding fluency aspects of spontaneous and read speech, the relationship between L1 and L2, the relationship between production and perception, and to the teaching of L2 English are discussed.

Effects of behavior inhibition on stuttering severity and adverse consequences of stuttering in 3-6-year-old children who stutter.

PURPOSE: The purpose of this study was to investigate whether 3- to-6-year-old children who stutter and exhibit a higher degree of behavioral inhibition (BI), a correlate of shyness, stutter more frequently and experience greater negative consequences of stuttering (per parent-report) than their peers who stutter but have lower BI. METHOD: Forty-six children who stutter (CWS; 35 boys & 11 girls; mean age 4 years, 2 months) participated. Their degree of BI was assessed by measuring the latency to their 6th spontaneous comment during a conversation with an unfamiliar examiner (following Kagan, Reznick, & Gibbons's (1989) methodology). The frequency of stuttering and the negative impact of stuttering that CWS may have experienced was assessed using parent reports (i.e., Test of Childhood Stuttering (TOCS) Observational Rating Scale; Gillam, Logan, & Pearson, 2009). RESULTS: We found that children's degree of BI was not associated with their speech fluency per parent report. However, children's degree of BI was significantly associated with greater negative consequences of stuttering. Specifically, among the four categories of TOCS Disfluency-Related Consequences, children's BI significantly predicted the occurrence of physical behaviors that accompany moments of stuttering (such as increased tension or excessive eye blinks). Other Disfluency-Related Consequences, such as avoidance behaviors, negative feelings, and negative social consequences, were not associated with children's behavioral inhibition tendencies. Additionally, children's stuttering severity (per the Stuttering Severity Instrument-4 scores) was significantly associated with increased physical behaviors that accompany moments of stuttering and greater negative social consequences of stuttering. CONCLUSIONS: This study provides empirical evidence that behavioral inhibition to the unfamiliar may have salience for childhood stuttering as it predicted the development of physical behaviors associated with stuttering (e.g., tension or struggle) in 3- to 6-year-old CWS. Clinical implications of high BI for the assessment and treatment of childhood stuttering are discussed.

Rate of Stuttering and Factors Associated With Speech Fluency Characteristics in Adult Struggling Readers.

Stuttering is a disorder that affects about 1% of the population and manifests as speech disfluencies. Reading difficulties and disabilities are commonly found in this population. Nonetheless, speech disfluencies have not been explored in adult struggling readers (ASRs). In the current study, we examined the rate of stuttering in ASRs as well as the relationships between their speech fluency and reading skills. A total of 120 participants were interviewed about their experiences with reading and administered standardized reading and reading-related assessments. Speech fluency and the criterion for stuttering were based on the interview. About 18.3% of the sample met the criterion for stuttering. ASRs who stutter (ASRs-S) and ASRs who do not stutter (ASRs-NS) did not differ in their reading and reading-related skills. ASRs-S had higher rates of negative correlations between reading and reading-related skills compared with ASRs-NS. Correlation patterns between performance on standardized assessments point to higher rates of uneven skills or dissociations in ASRs-S. These findings may have implications for the assessment and instruction for ASRs.

Investigating Aphasia Recovery: Demographic and Clinical Factors.

Post-stroke language recovery remains one of the main unresolved topics in the field of aphasia. In recent years, there have been efforts to identify specific factors that could potentially lead to improved language recovery. However, the exact relationship between the recovery of particular language functions and possible predictors, such as demographic or lesion variables, is yet to be fully understood. In the present study, we attempted to investigate such relationships in 42 patients with aphasia after left hemisphere stroke, focusing on three language domains: auditory comprehension, naming and speech fluency. Structural imaging data were also obtained for the identification of the lesion sites. According to our findings, patients demonstrated an overall improvement in all three language domains, while no demographic factor significantly contributed to aphasia recovery. Interestingly, specific lesion loci seemed to have a differential effect on language performance, depending on the time of testing (i.e., acute/subacute vs. chronic phase). We argue that this variability concerning lesion-deficit associations reflects the dynamic nature of aphasia and further discuss possible explanations in the framework of neuroplastic changes during aphasia recovery.

Neural activity during solo and choral reading: A functional magnetic resonance imaging study of overt continuous speech production in adults who stutter.

Previous neuroimaging investigations of overt speech production in adults who stutter (AWS) found increased motor and decreased auditory activity compared to controls. Activity in the auditory cortex is heightened, however, under fluency-inducing conditions in which AWS temporarily become fluent while synchronizing their speech with an external rhythm, such as a metronome or another speaker. These findings suggest that stuttering is associated with disrupted auditory motor integration. Technical challenges in acquiring neuroimaging data during continuous overt speech production have limited experimental paradigms to short or covert speech tasks. Such paradigms are not ideal, as stuttering primarily occurs during longer speaking tasks. To address this gap, we used a validated spatial ICA technique designed to address speech movement artifacts during functional magnetic resonance imaging (fMRI) scanning. We compared brain activity and functional connectivity of the left auditory cortex during continuous speech production in two conditions: solo (stutter-prone) and choral (fluency-inducing) reading tasks. Overall, brain activity differences in AWS relative to controls in the two conditions were similar, showing expected patterns of hyperactivity in premotor/motor regions but underactivity in auditory regions. Functional connectivity of the left auditory cortex (STG) showed that within the AWS group there was increased correlated activity with the right insula and inferior frontal area during choral speech. The AWS also exhibited heightened connectivity between left STG and key regions of the default mode network (DMN) during solo speech. These findings indicate possible interference by the DMN during natural, stuttering-prone speech in AWS, and that enhanced coordination between auditory and motor regions may support fluent speech.

Investigation of the effect of delayed auditory feedback and transcranial direct current stimulation (DAF-tDCS) treatment for the enhancement of speech fluency in adults who stutter: A randomized controlled trial.

BACKGROUND: Stuttering is a disorder that begins in childhood and can persist into adulthood. In the present study, it was hypothesized that the combined intervention of transcranial direct current stimulation (tDCS) and Delayed Auditory Feedback (DAF) would cause greater improvement in speech fluency in comparison to the intervention with DAF alone. METHODS: A randomized, double-blind, sham-controlled clinical trial was conducted to investigate the effects of the combined intervention. Fifty adults with moderate to severe stuttering (25 females, 25 males, Mean age=26.92, SD=6.23) were randomly allocated to the anodal or sham tDCS group. In the anodal tDCS group, participants received DAF combined with anodal tDCS (1 mA), while the sham tDCS group was exposed to sham tDCS simultaneously with DAF. In this study, a 60-ms delay was used for DAF intervention, and tDCS was applied over the left superior temporal gyrus. Each individual participated in six 20-minute intervention sessions (held on six consecutive days). Speech fluency was assessed before and after the intervention. RESULTS: In the anodal tDCS group, the scores of the Stuttering Severity Instrument, Overall Assessment of the Speaker's Experience of Stuttering questionnaire, and the percentage of stuttered syllable reduced significantly (from average baseline rates of 8.45%, across three tasks, to 5.36% at the follow-up assessment) after the intervention. CONCLUSION: The results of this study suggest that delivery of anodal tDCS when combined with DAF may enhance stuttering reduction effects for six weeks following the intervention.

Risk Factors for the Development of Persistent Stuttering: What Every Pediatrician Should Know.

Early identification and adequate treatment of children who stutter is important, since it has an impact on speech development. Considering the importance of aiding pediatricians to recognize children at risk for developing persistent stuttering, the aim of the present study was to correlate speech fluency characteristics of children, whose parents reported stuttering behaviors, to the risk factors of persistent stuttering. The participants were 419 children aged 2:0 to 11:11 years, who were divided into two groups: children with stuttering complaints (CSC), composed of children whose parents reported the presence of stuttering behaviors; and children with no stuttering complaint (CNSCs), composed of children with no stuttering behaviors. Risk variables were gathered based on a questionnaire answered by parents involving the following variables: sex, presence of family history of stuttering, whether stuttering behaviors were observed for more than 12 months, whether stuttering behaviors began before 5 years of age, increased effort to speak (i.e., syllable and sound repetitions and fixed articulatory positions), negative family attitude towards the child's speech, and negative attitude towards the child's own speech. The diagnosis of stuttering was determined by a formal speech assessment by a pathologist (SLP). The risk analysis indicated that increased effort to speak, negative family attitude towards the child's speech, and complaints of stuttering for more than 12 months were associated with a higher risk of stuttering in children. Therefore, when pediatricians are faced with complaints about the presence of stuttering behaviors and these factors are present, they should immediately refer the patient to an SLP for specific assessment.

Development of diagnosis, assessment and intervention solution for speech fluency disorder using WHO-FICs / 中国康复理论与实践

ObjectiveTo explore the diagnoses of diseases and functioning of speech fluency disorder, analyze the main assessment content, and construct framework of intervention solution based on International Classification of Diseases 11th Revision (ICD-11), International Classification of Functioning, Disability and Health (ICF) and International Classification of Health Interventions (ICHIβ-3). MethodsThe diagnoses of diseases and functioning was discussed with ICD-11 and ICF. The assessment tools were analyzed with ICF. A holistic intervention solution was constructed with ICF and ICHIβ-3. ResultsSpeech fluency disorder is classified as 6A01.1 developmental speech fluency disorder for ICD-11. The related diseases include 6A01.0 developmental speech sound disorder, 6A01.2 developmental language disorder, cerebral palsy, MA80.0 aphasia, MA80.1 dysphasia and MA80.2 dysarthria, etc. For ICF, the categories related to speech fluency disorder might be s3 structures invovled in voice and speech; b3 voice and speech functions, especially b330 fluency and rhythm of speech functions; d1 learning and applying knowledge, d3 communication, especially d330 speaking and d355 discussion, d7 interpersonal interactions and relationships, and d9 community, social and civic life. A holistic intervention solution for speech fluency disorder was developed, involving in body structure, body function, activities and participation, and environmental factors, including assessment, training and treatment, educational counseling, and psychological and social support, etc. ConclusionA framework of diagnosis, assessment and rehabilitation has been constructed for speech fluency disorder.

Awareness of stuttering in Japanese children aged 3-7 years.

BACKGROUND: Boey et al. (2009) devised a questionnaire for measuring children's awareness of stuttering and showed that even very young children were often aware of their stuttering. There has been no replication of studies using Boey et al.'s parent-reported questionnaire. The aim of this study was to test whether using Boey et al.'s seven questions, developed for a Dutch speaking population could be effective for measuring the awareness of stuttering in Japanese children. METHODS: Participants were 54 children who stutter (CWS) aged 3-7 years. Parents answered seven questions about their child's awareness of stuttering according to the questions developed Boey et al. RESULTS: Parental-reported observations of the child responses citing at least one awareness incident were 76%. The percentage of stuttering children with awareness of their own speech difficulties, according to chronological age, were as follows: 70% at age 3 years; 67% at age 4 years; 75% at age 5 years; 81% at age 6 years; and 90% at age 7 years. CONCLUSIONS: We found that even at age 3 years, many CWS were already aware of their stuttering. The similarity of the data with the seminal study by Boey et al. suggests that the question-based assessment is reproducible even in a country with a different spoken language. The seven questions in Boey et al. are useful for evaluating whether children's awareness of stuttering could contribute to a clinical decision as well as stuttering severity.

Disfluencias típicas del habla en niños fluentes de Santiago de Chile / Typical speech dysfluencies in fluent children from Santiago de Chile

El estudio de la fluidez del habla, en distintas etapas del ciclo vital, es relevante porque contribuye tanto a la comprensión del desarrollo típico del habla como a la comprensión del habla patológica, lo que aporta al diagnóstico y al tratamiento. Los objetivos del trabajo son: a) determinar la presencia y distribución de las disfluencias en distintos grupos etarios y b) determinar si existe variación en la distribución de las disfluencias en relación con el género de los informantes. La muestra estuvo compuesta por 60 niños y adolescentes entre los 4.01 años y 15.0 años distribuidos en tres grupos. Los resultados indican que la prolongación de vocal fue la disfluencia más frecuente, mientras que la repetición de sílaba fue la menos presente en los grupos analizados. En el grupo de mujeres de menor edad hubo una cantidad significativamente alta de repetición de palabras. No se encontraron otras diferencias en relación con el género de los informantes. Finalmente, se discuten los resultados y algunas consideraciones relacionadas con la metodología en este tipo de investigaciones.

The study of fluency of speech, at different stages of the life cycle, is relevant in that it contributes both to the understanding of typical speech development and to the understanding of pathological speech, which is useful for diagnosis and treatment. The objectives of this work are a) to determine the presence and distribution of the disfluencies present in different age groups and b) to determine if there is variation in the distribution of disfluencies in relation to the gender of the informants. Thesample consisted of 60 children and adolescents between 4.01 years old and 15.0 years old distributed in three groups. The results indicate that vowel prolongation was the most frequent disfluency, while syllable repetition was the least present inthe groups analyzed. In the group of younger women, there was a significantly high amount of word repetition when comparing the presence of this disfluency in the other two groups. There were no more differences reported in relation to the gender ofthe informants. Finally, the results and some considerations related to the methodology in this type of research are discussed

Neuronavigated rTMS inhibition of right pars triangularis anterior in stuttering: Differential effects on reading and speaking.

Functional neuroimaging studies show an overactivation of speech and language related homologous areas of the right hemisphere in persons who stutter. In this study, we inhibited Broca's homologues using 1 Hz repetitive transcranial magnetic stimulation (rTMS) and assessed its effects on stuttering severity. The investigated cortical areas included pars opercularis (BA44), anterior and posterior pars triangularis (BA45), mouth area on the primary motor cortex (BA4). We collected reading and speaking samples before and after rTMS sessions and calculated the percentage of syllables stuttered. Only right anterior pars triangularis stimulation induced significant changes in speech fluency. Notably, the effects were differential for reading and speaking conditions. Overall, our results provide supportive evidence that right anterior BA45 may be a critical region for stuttering. The observed differential effects following the inhibition of right anterior BA45 merits further study of contributions of this region on different language domains in persons who stutter.

Functional linguistic specificity of the left frontal aslant tract for spontaneous speech fluency: Evidence from intraoperative language mapping.

The left frontal aslant tract (FAT) has been proposed to be relevant for language, and specifically for spontaneous speech fluency. However, there is missing causal evidence that stimulation of the FAT affects spontaneous speech, and not language production in general. We present a series of 12 neurosurgical cases with awake language mapping of the cortex near the left FAT. Tasks for language mapping included the commonly used action picture naming, and sentence completion, tapping more specifically into spontaneous speech. A task dissociation was found in 10 participants: while being stimulated on specific sites, they were able to name a picture but could not complete a sentence. Overlaying of these sites on preoperative white-matter tract reconstructions revealed that in each individual case they were located on cortical terminations of the FAT. This corroborates the language functional specificity of the left FAT as a tract underlying fluent spontaneous speech.

Delayed Auditory Feedback and Transcranial Direct Current Stimulation Treatment for the Enhancement of Speech Fluency in Adults Who Stutter: Protocol for a Randomized Controlled Trial.

BACKGROUND: Stuttering is a complex speech disorder that affects speech fluency. Recently, it has been shown that noninvasive brain stimulation may be useful to enhance the results of fluency interventions in adults who stutter. Delayed auditory feedback (DAF) is a method to enhance speech fluency in individuals who stutter. Adjunctive interventions are warranted to enhance the efficacy of this intervention. OBJECTIVE: Individuals who stutter have pathological activation patterns in the primary and secondary auditory areas. Consequently, in this study, we hypothesize that stimulation of these areas might be promising as an adjunctive method to fluency training via DAF to enhance speech therapy success in individuals with a stutter. We will systematically test this hypothesis in this study. METHODS: This study is designed as a randomized, double-blind, sham-controlled clinical trial. All participants will receive DAF. The intervention group will additionally receive real transcranial direct current stimulation, while the control group will be exposed to sham stimulation. The assignment of the participants to one of these groups will be randomized. Before starting the treatment program, 2 preintervention assessments will be conducted to determine the severity of stuttering. Once these assessments are completed, each subject will participate in 6 intervention sessions. Postintervention assessments will be carried out immediately and 1 week after the last intervention session. Subsequently, to explore the long-term stability of the treatment results, the outcome parameters will be obtained in follow-up assessments 6 weeks after the treatment. The primary outcome measurement-the percentage of stuttered syllables-will be calculated in pre-, post-, and follow-up assessments; the secondary outcomes will be the scores of the following questionnaires: the Stuttering Severity Instrument-Fourth Edition and the Overall Assessment of the Speaker's Experience of Stuttering. RESULTS: This protocol was funded in 2019 and approved by the Research Ethics Committee of the Iran University of Medical Sciences in June 2019. Data collection started in October 2019. As of February 2020, we have enrolled 30 participants. We expect data analysis to be completed in April 2020, and results will be published in summer 2020. CONCLUSIONS: We anticipate that this study will show an adjunctive effect of transcranial direct current stimulation, when combined with DAF, on stuttering. This should include not only a reduction in the percentage of stuttered syllables but also improved physical behavior and quality of life in adults who stutter. TRIAL REGISTRATION: ClinicalTrial.gov NCT03990168; https://clinicaltrials.gov/ct2/show/NCT03990168. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/16646.

Surface Electrical Stimulation for Persistent Stuttering and Concomitant Orofacial Disorders: A Multiple Case Study.

This multiple case study analysis describes the immediate effects on speech fluency of transcutaneous electrical nerve stimulation (TENS) applied to participants with persistent stuttering and concomitant orofacial disorders. Study participants were 14 adolescents and adults who stuttered and had jaw clenching bruxism or mouth breathing. Participants experienced low-frequency TENS applied at mild motor level for 20 minutes with electrodes placed at the lower third of the face (Area A), submandibular region (Area B), posterior neck (Area C), or shoulder girdle (Area D), with speech fluency assessed immediately before and after each stimulation.For participants with stuttering and bruxism, AB stimulation reduced the median frequency of syllables stuttered by 27% and reduced the median duration of the three highest stuttering moments by 29%. In addition, for participants with stuttering and mouth breathing, CD stimulation reduced the median duration of the three highest stuttering moments by 28% and increased their median speech rate by 113%. As a single session of TENS may help participants with stuttering and concomitant orofacial disorders better use fluency shaping techniques, the therapeutic potential of TENS for treating stuttering should be further investigated.

Brain structures and cognitive abilities important for the self-monitoring of speech errors.

The brain structures and cognitive abilities necessary for successful monitoring of one's own speech errors remain unknown. We aimed to inform self-monitoring models by examining the neural and behavioral correlates of phonological and semantic error detection in individuals with post-stroke aphasia. First, we determined whether detection related to other abilities proposed to contribute to monitoring according to various theories, including naming ability, fluency, word-level auditory comprehension, sentence-level auditory comprehension, and executive function. Regression analyses revealed that fluency and executive scores were independent predictors of phonological error detection, while a measure of word-level comprehension related to semantic error detection. Next, we used multivariate lesion-symptom mapping to determine lesion locations associated with reduced error detection. Reduced overall error detection related to damage to a region of frontal white matter extending into dorsolateral prefrontal cortex (DLPFC). Detection of phonological errors related to damage to the same areas, but the lesion-behavior association was stronger, suggesting the localization for overall error detection was driven primarily by phonological error detection. These findings demonstrate that monitoring of different error types relies on distinct cognitive functions, and provide causal evidence for the importance of frontal white matter tracts and DLPFC for self-monitoring of speech.

Neural structures supporting spontaneous and assisted (entrained) speech fluency.

Non-fluent speech is one of the most common impairments in post-stroke aphasia. The rehabilitation of non-fluent speech in aphasia is particularly challenging as patients are rarely able to produce and practice fluent speech production. Speech entrainment is a behavioural technique that enables patients with non-fluent aphasia to speak fluently. However, its mechanisms are not well understood and the level of improved fluency with speech entrainment varies among individuals with non-fluent aphasia. In this study, we evaluated the behavioural and neuroanatomical factors associated with better speech fluency with the aid of speech entrainment during the training phase of speech entrainment. We used a lesion-symptom mapping approach to define the relationship between chronic stroke location on MRI and the number of different words per second produced during speech entrainment versus picture description spontaneous speech. The behavioural variable of interest was the speech entrainment/picture description ratio, which, if ≥1, indicated an increase in speech output during speech entrainment compared to picture description. We used machine learning (shallow neural network) to assess the statistical significance and out-of-sample predictive accuracy of the neuroanatomical model, and its regional contributors. We observed that better assisted speech (higher speech entrainment/picture description ratio) was achieved by individuals who had preservation of the posterior middle temporal gyrus, inferior fronto-occipital fasciculus and uncinate fasciculus, while exhibiting lesions in areas typically associated with non-fluent aphasia, such as the superior longitudinal fasciculus, precentral, inferior frontal, supramarginal and insular cortices. Our findings suggest that individuals with dorsal stream damage but preservation of ventral stream structures are more likely to achieve more fluent speech with the aid of speech entrainment compared to spontaneous speech. This observation provides insight into the mechanisms of non-fluent speech in aphasia and has potential implications for future research using speech entrainment for rehabilitation of non-fluent aphasia.