Speech Motor Research Articles

Multimodal human computer interaction of wheelchairs supporting lower limb active rehabilitation

Currently, an important challenge in stroke rehabilitation is how to effectively restore motor functions of lower limbs. This paper presents multimodal human computer interaction (HCI) of wheelchairs supporting lower limb active rehabilitation. First, multimodal HCI incorporating motor imagery electroencephalography (EEG), electromyography (EMG) and speech is designed. Second, prototype supporting wheelchair active rehabilitation method is illustrated in details. Third, the preliminary brain-computer interfaces (BCI) and speech recognition task experiments are carried out respectively, and the results are obtained. Finally, discussion is conducted and conclusion is drawn. This study has important practical significance in auxiliary movements and neurorehabilitation for stroke patients.

Global perspectives on tongue-tie assessment of one to ten year-old children in speech-language pathology

Purpose: Speech-language pathologists (SLPs) are essential in evaluating tongue structure and function. Due to limited psychometrically validated assessment tools, evidence-based practitioners often rely on clinical expertise to inform their assessment and clinical decision-making. This study aimed to explore how SLPs assess tongue structure and function in children aged 1 to 10 years suspected of having a tongue-tie by examining global practice patterns. Methods: A total of 194 practicing, English-speaking SLPs participated in a global online survey. The survey gathered information on participant demographics, classification tools used, and methods for assessing tongue structure and function, oral motor function and speech production in children with suspected tongue-tie. Results: Participants reported using various measures, including case history, oral examination, and clinical assessment. These measures encompassed evaluation of tongue structure, oral motor tasks and functional measures, including observation of speech, feeding, and swallowing. Notably, 40% of participants indicated they did not use any published assessment tool. While over 90% of participants evaluated feeding skills through parent questionnaires, only 55% observed feeding during mealtimes. Additionally, SLPs in the United States reported using different classification tools for tongue-tie compared to their counterparts in Australia, the United Kingdom and other countries. Conclusion: There is a global trend of limited use of published tongue-tie assessment tools in clinical practice. Most clinicians rely on various measures to evaluate tongue structure and function in children with suspected tongue-tie. These findings highlight the need for a specialized assessment tool that is designed and validated for evaluating tongue structure and function in children beyond infancy.

Clinical and functional characteristics of co-occurring cerebral palsy and autism spectrum disorder among children and young adults

BackgroundTo examine clinical and functional factors associated with co-occurring cerebral palsy (CP) and autism spectrum disorder (ASD). MethodsData were collected from the electronic health records of 994 patients with CP aged 3 to 26 years (59 % males) who received services from a U.S. hospital system between January 1, 2016 and July 1, 2021. CP, ASD, and other co-occurring conditions were abstracted using International Classification of Diseases - 10th Revision (ICD-10) codes, diagnostic summaries, and clinical descriptions. Bivariate and adjusted multivariable analyses examined the association between ASD, CP type, Gross Motor Function Classification System (GMFCS) level, speech or language disorders, and mental or behavioral problems. ResultsPrevalence of ASD was 8.2 % among patients with CP. Patients with GMFCS levels III-V were less likely to have a diagnosis of ASD (adjusted odds ratio [AOR] = 0.21; 95 % confidence interval [CI], 0.11–0.41). However, speech or language disorders (AOR = 6.00; 95 % CI, 2.14–16.81) and mental or behavioral problems (AOR =8.79; 95 % CI, 4.99–15.49) were associated with significantly higher odds of ASD. ConclusionsChildren and young adults with co-occurring CP and ASD have higher prevalence of clinical and functional impairments compared with counterparts with CP without co-occurring ASD. Screening for both conditions is necessary because of the high prevalence of ASD in this population. It is also necessary to implement specialized assessment procedures to decrease the risk of misclassifying or overlooking ASD among children and young adults with CP.

Expanding the molecular landscape of childhood apraxia of speech: evidence from a single-center experience.

Childhood apraxia of speech (CAS) is a genetically heterogeneous pediatric motor speech disorder. The advent of whole exome sequencing (WES) and whole genome sequencing techniques has led to increased identification of pathogenic variants in CAS genes. In an as yet uncharacterized Italian cohort, we aimed both to identify new pathogenic gene variants associated with CAS, and to confirm the disease-related role of genes already reported by others. We also set out to refine the clinical and neurodevelopmental characterization of affected children, with the aim of identifying specific, gene-related phenotypes. In a single-center study aiming to explore the genetic etiology of CAS in a cohort of 69 Italian children, WES was performed in the families of the 34 children found to have no copy number variants. Each of these families had only one child affected by CAS. High-confidence (HC) gene variants were identified in 7/34 probands, in two of whom they affected KAT6A and CREBBP, thus confirming the involvement of these genes in speech impairment. The other probands carried variants in low-confidence (LC) genes, and 20 of these variants occurred in genes not previously reported as associated with CAS. UBA6, ZFHX4, and KAT6A genes were found to be more enriched in the CAS cohort compared to control individuals. Our results also showed that most HC genes are involved in epigenetic mechanisms and are expressed in brain regions linked to language acquisition processes. Our findings confirm a relatively high diagnostic yield in Italian patients.

Exploring Adaptive Virtual Reality Systems Used in Interventions for Children With Autism Spectrum Disorder: Systematic Review.

Adaptive systems serve to personalize interventions or training based on the user's needs and performance. The adaptation techniques rely on an underlying engine responsible for processing incoming data and generating tailored responses. Adaptive virtual reality (VR) systems have proven to be efficient in data monitoring and manipulation, as well as in their ability to transfer learning outcomes to the real world. In recent years, there has been significant interest in applying these systems to improve deficits associated with autism spectrum disorder (ASD). This is driven by the heterogeneity of symptoms among the population affected, highlighting the need for early customized interventions that target each individual's specific symptom configuration. Recognizing these technology-driven therapeutic tools as efficient solutions, this systematic review aims to explore the application of adaptive VR systems in interventions for young individuals with ASD. An extensive search was conducted across 3 different databases-PubMed Central, Scopus, and Web of Science-to identify relevant studies from approximately the past decade. Each author independently screened the included studies to assess the risk of bias. Studies satisfying the following inclusion criteria were selected: (1) the experimental tasks were delivered via a VR system, (2) system adaptation was automated, (3) the VR system was designed for intervention or training of ASD symptoms, (4) participants' ages ranged from 6 to 19 years, (5) the sample included at least 1 group with ASD, and (6) the adaptation strategy was thoroughly explained. Relevant information extracted from the studies included the sample size and mean age, the study's objectives, the skill trained, the implemented device, the adaptive strategy used, the engine techniques, and the signal used to adapt the systems. Overall, a total of 10 articles were included, involving 129 participants, 76% of whom had ASD. The studies included level switching (7/10, 70%), adaptive feedback strategies (9/10, 90%), and weighing the choice between a machine learning (ML) adaptive engine (3/10, 30%) and a non-ML adaptive engine (8/10, 80%). Adaptation signals ranged from explicit behavioral indicators (6/10, 60%), such as task performance, to implicit biosignals, such as motor movements, eye gaze, speech, and peripheral physiological responses (7/10, 70%). The findings reveal promising trends in the field, suggesting that automated VR systems leveraging real-time progression level switching and verbal feedback driven by non-ML techniques using explicit or, better yet, implicit signal processing have the potential to enhance interventions for young individuals with ASD. The limitations discussed mainly stem from the fact that no technological or automated tools were used to handle data, potentially introducing bias due to human error.

Tipping the Scales: Indiscriminate Use of Interval Scales to Rate Diverse Dysarthric Features.

Error related to incorrect use of rating scales is problematic in the assessment and treatment of dysarthria. The main purpose of this project was to determine scale fit for cardinal speech features of hypokinetic dysarthria. A secondary aim was to determine rater reliability for the two different scales explored. Forty-three speakers with Parkinson's disease (PD) and 25 neurologically healthy control talkers were recorded reading sentences from the Speech Intelligibility Test. Twenty-two healthy female listeners used both an equal appearing interval (EAI) scale and a direct magnitude estimation (DME) scale to rate five perceptual speech features (i.e., overall speech severity, articulatory imprecision, reduced loudness, short rushes of speech, and monotony) from these recordings. Regression analyses were used to determine the linearity of the relationship between the means of the EAI and DME ratings. Inter- and intrarater reliability was calculated using intraclass correlation coefficients and Spearman's correlation coefficients, respectively, for both EAI and DME ratings. There was a linear relationship between EAI and DME means for monotony, indicating it is a metathetic dimension. Curvilinear relationships were observed between the EAI and DME means for the other four features, indicating prothetic dimensions. Intra- and interrater reliability values were similar for EAI and DME ratings. Overall, results of this work suggest that DME is the best fit for scaling several hypokinetic dysarthria features, and not the conventionally used EAI scale. Prothetic dimensions best scaled by DME include overall speech severity, articulatory imprecision, reduced loudness, and short rushes of speech. Monotony was the only feature found to be a metathetic dimension and would be best scaled using EAI or DME. Findings call for rethinking the widespread use of EAI scales for rating perceptual features as part of the assessment and treatment of motor speech disorders.

A historical perspective on the neurobiology of speech and language: from the 19th century to the present.

In this essay, we review 19th century conceptions on the neurobiology of speech and language, including the pioneer work of Franz Gall, Jean-Baptiste Bouillaud, Simon Alexandre Ernest Aubertin, Marc Dax, Paul Broca, and Carl Wernicke. We examine how these early investigations, anchored in the study of neurological disorders, have broadened their scope via neuropsychological and psycholinguistic theories and models. Then, we discuss how major technological advances have led to an important paradigm shift, through which the study of the brain slowly detached from the study of disease to become the study of individuals of all ages, with or without brain pathology or language disorders. The profusion of neuroimaging studies that were conducted in the past four decades, inquiring into various aspects of language have complemented-and often challenged-classical views on language production. Our understanding of the "motor speech center," for instance, has been entirely transformed. The notion of cerebral dominance has also been revisited. We end this paper by discussing the challenges and controversies of 21st century neurobiology of speech and language as well as modern views of the neural architecture supporting speech and language functions.

Acquired motor speech disorders in childhood epilepsy.

To evaluate a group of children with epilepsy and motor speech regression, with the aim of characterizing their speech disorders, electrographic features, and outcomes. Children referred to a tertiary developmental epilepsy clinic with epilepsy and motor speech regression were identified retrospectively. A clinical history was taken, and longitudinal speech and cognitive data were recorded. Speech samples were scored for severity and speech features. Seizure frequency and epileptiform discharges in the interictal electroencephalogram were analysed. Eighteen children (10 female) were evaluated, including seven with Landau-Kleffner syndrome and six with Rasmussen syndrome. Speech regression occurred at a mean age of 5 years (SD = 2 years 6 months), which was concurrent with seizure onset or peak seizure burden in eight children. Speech features included dysarthria (n = 13), phonological errors (n = 7), and dyspraxia (n = 6). Electrographic abnormalities occurred most frequently in the left centrotemporal and right frontal regions. Among children who were followed up, intelligibility of speech was affected in 13 at baseline and seven at follow-up (p = 0.03). Expressive language standardized scores increased from a mean (SD) of 50.0 (11.3) to 91.4 (27.8) in children with Landau-Kleffner syndrome (mean change = 41.4, 95% confidence interval [CI] 0.04-82.8, p = 0.0498) and decreased from 75.2 (15.3) to 59.0 (9.8) in children with Rasmussen syndrome (mean change -16.2, 95% CI -9.0 to -23.4, p = 0.002) over the follow-up. Motor speech disorders in epilepsy were severe, multifarious, and often fluctuated with seizure burden. Symptoms typically improved, especially in children with Landau-Kleffner syndrome, but rarely fully resolved.

Utilization of Western Aphasia Battery–Revised Spoken Language Subtest Stimuli to Characterize Differentially Diagnostic Characteristics of Acquired Apraxia of Speech

Purpose: There is a need for stimuli that can be used in the assessment of apraxia of speech (AOS) characteristics. AOS often presents with aphasia, and the Western Aphasia Battery–Revised (WAB-R) is administered extensively in clinical practice for the assessment of aphasia. This preliminary study investigated error production of differentially diagnostic characteristics of AOS (phonetic and prosodic errors) in response to existing spoken language subtest stimuli of the WAB-R in individuals with concomitant AOS and aphasia and aphasia only. Method: Ten participants presenting with aphasia and potential motor speech impairment were included. Presence of AOS was determined for five individuals. Speech production errors were analyzed using narrow transcription methods in response to the Naming, Repetition, and Spontaneous Speech subtests of the WAB-R for both AOS and aphasia and aphasia-only groups. Results: Differences in total error production for both phonetic and prosodic errors were reported between the AOS and aphasia and aphasia-only groups. In addition, the phonetic complexity of the stimuli correlated to the phonetic and prosodic error production in both groups. An effect of WAB-R subtest was not reported for either group. Conclusion: The diversity of elicited spoken language production across multiple contexts makes the use of the spoken language subtest stimuli a feasible component of a comprehensive AOS assessment, since AOS is often concomitant with aphasia.

Introduction to the Forum: Native Language, Dialect, and Foreign Accent in Dysarthria.

This timely collection is an international effort to serve as a foundation to encourage research that offers insights into the interaction between language variation and motor speech disorders. Specifically, this forum aimed to provide a platform that (a) explores and demonstrates the role of language variation in the manifestation of dysarthria, (b) considers language variation in clinical assessment and management, and (c) promotes awareness of diverse language backgrounds of people with dysarthria. The forum contains six articles, spanning a variety of research designs (cross-sectional, pre- and post-treatment), kinds of articles (tutorial, research article, commentary), and a range of languages from around the world (English, French, Korean Portuguese, Spanish).

Discordant Wada and fMRI language lateralization: a case report.

Functional MRI (fMRI) is gaining importance in the preoperative assessment of language for presurgical planning. However, inconsistencies with the Wada test might arise. This current case report describes a very rare case of an epileptic patient who exhibited bilateral distribution (right > left) in the inferior frontal gyrus (laterality index [LI] = -0.433) and completely right dominance in the superior temporal gyrus (LI = -1). However, the Wada test revealed a dissociation: his motor speech was located in the left hemisphere, while he could understand vocal instructions with his right hemisphere. A clinical implication is that the LIs obtained by fMRI should be cautiously used to determine Broca's area in atypical patients; for example, even when complete right dominance is found in the temporal cortex in right-handed patients. Theoretically, as the spatially separated functions of motor speech and language comprehension (by the combined results of fMRI and Wada) can be further temporally separated (by the intracarotid amobarbital procedure) in this case report, these findings might provide direct support to Broca's initial conclusions that Broca's area is associated with acquired motor speech impairment, but not language comprehension per se. Moreover, this current finding supports the idea that once produced, motor speech can be independent from language comprehension.

MED13L-related disorder characterized by severe motor speech impairment.

MED13L-related disorder is associated with intellectual disability, motor delay, and speech deficits. Previous studies have focused on broad clinical descriptions of individuals, but limited information regarding specific speech diagnoses and results of direct testing has been published to date. We conducted deep phenotyping to characterize the speech, language, motor, cognitive, and adaptive phenotypes of individuals with MED13L-related disorder. In this cross-sectional study, we administered standardized articulation, language, motor, and cognitive testing to 17 children and adolescents (mean age 9y 9m; SD 4y 5m; range 4y 2m to 19y 7m). In-person testing was supplemented with broad developmental, medical, and behavioral information collected virtually from a cohort of 67 individuals. All individuals who completed in-person articulation testing met diagnostic criteria for speech apraxia, dysarthria, or both. Language impairment was present in all of the in-person cohort and almost all (97%) of the virtual cohort. Those who were able to complete motor testing demonstrated significant deficits in visual motor integration (mean 57.08, SD 9.26). Full scale IQs fell in the borderline to intellectual disability range, consistent with reported cognitive impairment in 97% of the virtual cohort. Notable medical features included hypotonia (83%), vision problems (72%), recurrent otitis media (58%), gastrointestinal problems (57%), and seizures (31%). MED13L-related disorder is characterized by a high rate of motor speech disorders that occur in the context of globally impaired motor, language, and cognitive skills. Children would benefit from intensive, individualized speech therapy and the early adoption of augmentative communication strategies.

The impact of headache intensity on speech in participants with migraine and acute post-traumatic headache.

Slower speaking rates and higher pause rates are found in individuals with migraine or post-traumatic headache during headache compared to when headache-free. We aimed to determine whether headache intensity influences the speaking rate and pause rate of participants with migraine or acute post-traumatic headache (aPTH) following mild traumatic brain injury (mTBI). Using a speech elicitation tool, participants with migraine, aPTH, and healthy controls (HC) submitted speech samples over a period of 3 months. Speaking and pause rates were calculated when participants were headache-free and when they had mild or moderate headache. In this observational study, speaking and pause rates in participants with migraine and aPTH were compared to HC, controlling for age, sex, and days since mTBI (participants with aPTH only). A total of 2902 longitudinal speech samples from 13 individuals with migraine (mean age = 33.5, SD = 6.6; 12 females/1 male), 43 individuals with aPTH (mean age = 44.4, SD = 13.5; 28 females/15 males), and 56 HC (mean age = 40.8, SD = 13.0; 36 females/20 males) were collected. There was no difference in speaking rate between HC and the combined headache cohort of participants (migraine and aPTH) when they had headache freedom or a mild headache. When participants had moderate intensity headache, their speaking rate was significantly slower compared to that of HC and compared to their speaking rate during mild headache intensity or headache freedom. For the combined headache cohort of participants, pause rates were significantly higher when they had headache freedom or had a headache of mild or moderate intensity relative to HC. Compared to participants' pause rate during headache freedom, their pause rate was significantly higher during mild and moderate headache intensity. Participants with aPTH had significantly slower speaking rates compared to participants with migraine during headache freedom, mild headache intensity, and moderate headache intensity. Participants with aPTH had significantly higher pause rates compared to participants with migraine when experiencing moderate headache intensity. For both aPTH and migraine, more severe headache pain was associated with higher pause rates and slower speaking rates, suggesting that speaking rate and pause rate could serve as objective biomarkers for headache-related pain. Slower speaking rate in participants with aPTH could reflect additional consequences of TBI-related effects on motor control and speech production.

‛Until you're in the chair and executing your role, you don't know': A qualitative study of the needs and perspectives of people with stroke-related communication disabilities when returning to vocational activity.

People with communication disability after stroke experience low rates of return to vocational roles. Vocational rehabilitation is recommended; however, there are no clear guidelines informing vocational rehabilitation for people with communication disability. Understanding the needs and experiences of this population is critical to improving vocational stroke rehabilitation outcomes. This study aimed to: (1) investigate the experience of vocational rehabilitation for people with communication disability after stroke, (2) identify gaps and, (3) provide preliminary recommendations for tailored service delivery. Seven participants with an identified communication impairment following stroke were recruited from a larger clinical trial of early vocational rehabilitation (20% of total sample, n = 34). To address the study aims, a qualitative design was employed. Semi-structured, in-depth interviews were conducted and analysed using thematic analysis. Data were integrated with demographic and intervention audit data to contextualise participant experiences, identify vocational rehabilitation gaps and inform preliminary recommendations. Participants were five men and two women aged 24-69 years whose communication profiles included difficulties with auditory comprehension and information processing, reading comprehension, thinking, executive function and self-regulation, as well as difficulties with verbal and written expression. Vocational rehabilitation was perceived as beneficial but participants identified gaps including limited access to psychological and peer-based support during early rehabilitation, limitations to accessing specialist vocational rehabilitation programs, barriers to accessing ongoing rehabilitation after resumption of vocational activity, and limited preparedness for the degree of impact that their communication changes had on execution of vocational roles and responsibilities. Vocational environments are communicatively demanding and people living with acquired communication difficulties face a range of vocation-related participation barriers even when communication difficulties are mild. Greater emphasis on evaluating the vocational communication environment and targeted communication training and preparation for colleagues within the workplace is recommended to reduce barriers faced. Interdisciplinary rehabilitation, inclusive of psychological care, may support working-age stroke survivors to recognise and acknowledge changes in their communication function, lead to improved engagement in the rehabilitation process, and ensure early identification of factors likely to influence successful return-to-vocational activity. What is already known on the subject Stroke is common amongst people of working age yet fewer than half of stroke survivors will return to pre-stroke vocational roles. Communication difficulties affect anywhere between 24% and 45% of people after stroke and include changes to language abilities, motor speech, vision, hearing and cognition. This group experiences much lower rates of return to vocational roles when compared to people with stroke who do not have a concomitant communication difficulty. Vocational rehabilitation is recommended. However, currently there is limited evidence to inform vocational rehabilitation guidelines for people with stroke and communication difficulties. Achieving a successful return to vocational activity is associated with improved life satisfaction for people with communication difficulties after stroke and is a key research priority for this population. What this study adds This study investigated the experiences of people with communication difficulty after stroke who reported a goal of returning to pre-stroke vocational activity. Data associated with types of interventions received, the experiences and perceptions of vocational rehabilitation, and experiences of returning to vocational activity were analysed to identify core rehabilitation needs and develop preliminary recommendations to inform future vocational rehabilitation guidelines for this population. What are the clinical implications of this work? The present study provides preliminary evidence that people experiencing communication difficulties after stroke require a more integrated rehabilitation pathway. During early stages of vocational rehabilitation psychological and peer-based support is indicated to support adjustment to changed communication function and to enable productive goal setting and engagement in rehabilitation. Clinicians need to complete a detailed analysis of the vocational communication environment and consider the communication activities involved in the individual's future vocational duties in order to plan meaningful rehabilitation. A multidisciplinary approach is required and additional training for clinicians is indicated to support clinicians to work collaboratively within the vocational setting.

Prosody matters: Preserved prominence marking strategies in people with Parkinson's disease independent of motor status.

While many studies focus on segmental variation in Parkinsonian speech, little is known about prosodic modulations reflecting the ability to adapt to communicative demands in people with Parkinson's disease (PwPD). This type of prosodic modulation is important for social interaction, and it involves modifications in speech melody (intonational level) and articulation of consonants and vowels (segmental level). The present study investigates phonetic cues of prosodic modulations with respect to different focus structures in mild dysarthric PwPD as a function of levodopa. Acoustic and kinematic speech parameters of 25 PwPD were assessed in two motor conditions. Speech production data from PwPD were collected before (medication-OFF) and after levodopa intake (medication-ON) by means of 3-D electromagnetic articulography. On the acoustic level, intensity, pitch, and syllable durations were analyzed. On the kinematic level, movement duration and amplitude were investigated. Spatio-temporal modulations of speech parameters were examined and compared across three different prosodic focus structures (out-of-focus, broad focus, contrastive focus) to display varying speech demands. Overall, levodopa had beneficial effects on motor performance, speech loudness, and pitch modulation. Acoustic syllable durations and kinematic movement durations did not change, revealing no systematic effects of motor status on the temporal domain. In contrast, there were spatial modulations of the oral articulators: tongue tip movements were smaller and lower lip movements were larger in amplitude under levodopa, reflecting a more agile and efficient articulatory movement under levodopa. Thus, respiratory-phonatory functions and consonant production improved, while syllable duration and tongue body kinematics did not change. Interestingly, prominence marking strategies were comparable between the medication conditions under investigation, and in fact, appear to be preserved in mild dysarthric PwPD.

Accurate synthesis of dysarthric Speech for ASR data augmentation

Dysarthria is a motor speech disorder often characterized by reduced speech intelligibility through slow, uncoordinated control of speech production muscles. Automatic Speech Recognition (ASR) systems can help dysarthric talkers communicate more effectively. However, robust dysarthria-specific ASR requires a significant amount of training speech, which is not readily available for dysarthric talkers.This paper presents a new dysarthric speech synthesis method for the purpose of ASR training data augmentation. Differences in prosodic and acoustic characteristics of dysarthric spontaneous speech at varying severity levels are important components for dysarthric speech modeling, synthesis, and augmentation. For dysarthric speech synthesis, a modified neural multi-talker TTS is implemented by adding a dysarthria severity level coefficient and a pause insertion model to synthesize dysarthric speech for varying severity levels.To evaluate the effectiveness for synthesis of training data for ASR, dysarthria-specific speech recognition was used. Results show that a DNNHMM model trained on additional synthetic dysarthric speech achieves relative Word Error Rate (WER) improvement of 12.2 % compared to the baseline, and that the addition of the severity level and pause insertion controls decrease WER by 6.5 %, showing the effectiveness of adding these parameters. Overall results on the TORGO database demonstrate that using dysarthric synthetic speech to increase the amount of dysarthric-patterned speech for training has significant impact on the dysarthric ASR systems. In addition, we have conducted a subjective evaluation to evaluate the dysarthricness and similarity of synthesized speech. Our subjective evaluation shows that the perceived dysarthricness of synthesized speech is similar to that of true dysarthric speech, especially for higher levels of dysarthria. Audio samples are available at https://mohammadelc.github.io/SpeechGroupUKY/

The characteristics and reproducibility of motor speech functional neuroimaging in healthy controls.

Functional magnetic resonance imaging (fMRI) can improve our understanding of neural processes subserving motor speech function. Yet its reproducibility remains unclear. This study aimed to evaluate the reproducibility of fMRI using a word repetition task across two time points. Imaging data from 14 healthy controls were analysed using a multi-level general linear model. Significant activation was observed during the task in the right hemispheric cerebellar lobules IV-V, right putamen, and bilateral sensorimotor cortices. Activation between timepoints was found to be moderately reproducible across time in the cerebellum but not in other brain regions. Preliminary findings highlight the involvement of the cerebellum and connected cerebral regions during a motor speech task. More work is needed to determine the degree of reproducibility of speech fMRI before this could be used as a reliable marker of changes in brain activity.

Dysfluency in primary progressive aphasia: Temporal speech parameters

ABSTRACT Analysing spontaneous speech in individuals experiencing fluency difficulties holds potential for diagnosing speech and language disorders, including Primary Progressive Aphasia (PPA). Dysfluency in the spontaneous speech of patients with PPA has mostly been described in terms of abnormal pausing behaviour, but the temporal features related to speech have drawn little attention. This study compares speech-related fluency parameters in the three main variants of PPA and in typical speech. Forty-three adults participated in this research, thirteen with the logopenic variant of PPA (lvPPA), ten with the non-fluent variant (nfvPPA), nine with the semantic variant (svPPA), and eleven who were healthy age-matched adults. Participants’ fluency was assessed through a picture description task from which 42 parameters were computed including syllable duration, speaking pace, the duration of speech chunks (i.e. interpausal units, IPU), and the number of linguistic units per IPU and per second. The results showed that each PPA variant exhibited abnormal speech characteristics reflecting various underlying factors, from motor speech deficits to higher-level issues. Out of the 42 parameters considered, 37 proved useful for characterising dysfluency in the three main PPA variants and 35 in distinguishing among them. Therefore, taking into account not only pausing behaviour but also temporal speech parameters can provide a fuller understanding of dysfluency in PPA. However, no single parameter by itself sufficed to distinguish one PPA group from the other two, further evidence that dysfluency is not dichotomous but rather multidimensional, and that complementary multiparametric analyses are needed.

Automatic Speech Recognition in Primary Progressive Apraxia of Speech.

Transcribing disordered speech can be useful when diagnosing motor speech disorders such as primary progressive apraxia of speech (PPAOS), who have sound additions, deletions, and substitutions, or distortions and/or slow, segmented speech. Since transcribing speech can be a laborious process and requires an experienced listener, using automatic speech recognition (ASR) systems for diagnosis and treatment monitoring is appealing. This study evaluated the efficacy of a readily available ASR system (wav2vec 2.0) in transcribing speech of PPAOS patients to determine if the word error rate (WER) output by the ASR can differentiate between healthy speech and PPAOS and/or among its subtypes, whether WER correlates with AOS severity, and how the ASR's errors compare to those noted in manual transcriptions. Forty-five patients with PPAOS and 22 healthy controls were recorded repeating 13 words, 3 times each, which were transcribed manually and using wav2vec 2.0. The WER and phonetic and prosodic speech errors were compared between groups, and ASR results were compared against manual transcriptions. Mean overall WER was 0.88 for patients and 0.33 for controls. WER significantly correlated with AOS severity and accurately distinguished between patients and controls but not between AOS subtypes. The phonetic and prosodic errors from the ASR transcriptions were also unable to distinguish between subtypes, whereas errors calculated from human transcriptions were. There was poor agreement in the number of phonetic and prosodic errors between the ASR and human transcriptions. This study demonstrates that ASR can be useful in differentiating healthy from disordered speech and evaluating PPAOS severity but does not distinguish PPAOS subtypes. ASR transcriptions showed weak agreement with human transcriptions; thus, ASR may be a useful tool for the transcription of speech in PPAOS, but the research questions posed must be carefully considered within the context of its limitations. https://doi.org/10.23641/asha.26359417.

Increased vowel contrast and intelligibility in connected speech induced by sensorimotor adaptation.

Alterations to sensory feedback can drive robust adaptive changes to the production of consonants and vowels, but these changes often have no behavioral relevance or benefit to communication (e.g., making "head" more like "had"). This work aims to align the outcomes of adaptation with changes known to increase speech intelligibility - specifically, adaptations that increase the acoustic contrast between vowels in running speech. To this end, we implemented a vowel centralization feedback perturbation paradigm that pushes all vowels towards the center of vowel space, making them sound less distinct from one another. Speakers across the adult lifespan adapted to the centralization perturbation during sentence production, increasing the global acoustic contrast among vowels and the articulatory excursions for individual vowels. These changes persisted after the perturbation was removed, including after a silent delay, and showed robust transfer to words that were not present in the sentences. Control analyses demonstrated that these effects were unlikely to be due to explicit pronunciation strategies and occurred in the face of increasingly more rapid and less distinct production of familiar sentences. Finally, sentence transcription by crowd-sourced listeners showed that speakers' vowel contrast predicted their baseline intelligibility and that experimentally-induced increases in contrast predicted intelligibility gains. These findings establish the validity of a sensorimotor adaptation paradigm to implicitly increase vowel contrast and intelligibility in connected speech, an outcome that has the potential to enhance rehabilitation in individuals who present with a reduced vowel space due to motor speech disorders, such as the hypokinetic dysarthria associated with Parkinson's disease.