133 research outputs found

    Computational Language Assessment in patients with speech, language, and communication impairments

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    Speech, language, and communication symptoms enable the early detection, diagnosis, treatment planning, and monitoring of neurocognitive disease progression. Nevertheless, traditional manual neurologic assessment, the speech and language evaluation standard, is time-consuming and resource-intensive for clinicians. We argue that Computational Language Assessment (C.L.A.) is an improvement over conventional manual neurological assessment. Using machine learning, natural language processing, and signal processing, C.L.A. provides a neuro-cognitive evaluation of speech, language, and communication in elderly and high-risk individuals for dementia. ii. facilitates the diagnosis, prognosis, and therapy efficacy in at-risk and language-impaired populations; and iii. allows easier extensibility to assess patients from a wide range of languages. Also, C.L.A. employs Artificial Intelligence models to inform theory on the relationship between language symptoms and their neural bases. It significantly advances our ability to optimize the prevention and treatment of elderly individuals with communication disorders, allowing them to age gracefully with social engagement.Comment: 36 pages, 2 figures, to be submite

    Verbal monitoring in production and perception : a cognitive neuroscience approach

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    The goal of this dissertation is to investigate the process of verbal monitoring. Specifically, this thesis investigates whether internal and external monitoring proceeds via the same, perception-based process, as proposed by the perceptual loop theory. We compare verbal internal and external monitoring with the use of eye-tracking, fMRI and Parkinson patient data. The data obtained suggest that verbal monitoring is not perception based, and that is a domain general process. We therefore propose the improvement of current monitoring models by describing a domain general monitoring mechanism for internal monitoring and external monitoring, by which conflict is resolved in a process-independent manner

    PERIORAL BIOMECHANICS, KINEMATICS, AND ELECTROPHYSIOLOGY IN PARKINSON'S DISEASE

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    This investigation quantitatively characterized the orofacial biomechanics, labial kinematics, and associated electromyography (EMG) patterns in individuals with Parkinson's disease (PD) as a function of anti-PD medication state. Passive perioral stiffness, a clinical correlate of rigidity, was sampled using a face-referenced OroSTIFF system in 10 mildly diagnosed PD and 10 age/sex-matched control elderly. Labial movement amplitudes and velocities were evaluated using a 4-dimensional computerized motion capture system. Associated perioral EMG patterns were sampled to examine the characteristics of perioral muscles and compensatory muscular activation patterns during repetitive syllable productions. This study identified several trends that reflect various characteristics of perioral system differences between PD and control subjects: 1. The presence of high tonic EMG patterns after administration of dopaminergic treatment indicated an up-regulation of the central mechanism, which may serve to regulate orofacial postural control. 2. Multilevel regression modeling showed greater perioral stiffness in PD subjects, confirming the clinical correlate of rigidity in these patients. 3. Similar to the clinical symptoms in the upper and lower limb, a reduction of range of motion (hypokinesia) and velocity (bradykinesia) was evident in the PD orofacial system. Administration of dopaminergic treatment improved hypokinesia and bradykinesia. 4. A significant correlation was found between perioral stiffness and the range of labial movement, indicating these two symptoms may result in part from a common neural substrate. 5. As speech rate increased, PD speakers down-scaled movement amplitude and velocity compared to the control subjects, reflecting a compensatory mechanism to maintain target speech rates. 6. EMG from orbicularis oris inferior (OOIm) and depressor labii inferioris (DLIm) muscles revealed a limited range of muscle activation level in PD speakers, reflecting the underlying changes in motor unit firing behavior due to basal ganglia dysfunction. The results of this investigation provided a quantitative description of the perioral stiffness, labial kinematics, and EMG patterns in PD speakers. These findings indicate that perioral stiffness may provide clinicians a quantitative biomechanical correlate to medication response, movement aberrations, and EMG compensatory patterns in PD. The utilization of these objective assessments will be helpful in diagnosing, assessing, and monitoring the progression of PD to examine the efficacy of pharmacological, neurosurgical, and behavioral interventions

    A kinematic analysis of hand configurations in static and dynamic fingerspelling

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    The focus of this study was the investigation of target handshapes in American Sign Language fingerspelling in order to determine whether there was a difference between static canonical structures and structures produced in the context of a movement sequence. This was achieved by measuring the joint angles of a signing hand with an 18-sensor CyberGlove® by Virtual Technologies, Inc. A discriminant analysis was used to identify targets that occurred at points of minimum angular joint velocity. A multivariate analysis of variance with planned compansons was then applied to these dynamic data along with the static data to test the hypothesis. The results showed that there was a significant difference between handshapes produced statically and those produced dynamically, which suggested that a simple, cipher model of static handshapes produced within the context of a movement sequence is not sufficient to account for the production and perception of fingerspelling. These findings may be applied to future research in sign language recognition, so that consideration of the variability of target handshapes, as influenced by the spatiotemporal environment, might be incorporated into future models

    The detrimental effect of semantic similarity in short-term memory tasks: A meta-regression approach

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    The literature suggests that semantic similarity has a weak or null effect for immediate serial reconstruction and a facilitative effect for immediate serial recall. These observed semantic similarity effects are inconsistent with the assumptions of short-term memory (STM) models on the detrimental effect of similarity (e.g., confusion) and with observations of a robust detrimental effect of phonological similarity. Our review indicates that the experimental results are likely dependent on the manipulation strength for semantic similarity and that manipulations used in previous studies might have affected semantic assvociation as well as semantic similarity. To address these possible issues, two indices are proposed: (a) strength of manipulation on semantic similarity, gained by quantifying semantic similarity based on Osgood and associates’ dimensional view of semantics, and (b) inter-item associative strength, a possible confounding factor. Our review and the results of a meta-regression analysis using these two indices suggest that semantic similarity has a detrimental effect on both serial reconstruction and serial recall, while semantic association, which is correlated with semantic similarity, contributes to an apparent facilitative effect. An effect that is not attributable to similarity or association was also implied. Review on item and order memory further suggests the facilitative effect of semantic association on item memory and the detrimental effect of the semantic similarity on order memory. Based on our findings, we propose a unified explanation of observations of semantic similarity effects for both serial reconstruction and serial recall that is in good accord with STM models

    Models and Analysis of Vocal Emissions for Biomedical Applications

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    The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

    Dementia in Parkinson’s Disease

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    An estimated 50% to 80% of individuals with Parkinson’s disease experience Parkinson’s disease dementia (PDD). Based on the prevalence and clinical complexity of PDD, this book provides an in-depth update on topics including epidemiology, diagnosis, and treatment. Chapters discuss non-medical therapies and examine views on end-of-life issues as well. This book is a must-read for anyone interested in PDD whether they are a patient, caregiver, or doctor

    New perspectives on speech motor planning and programming in the context of the four- level model and its implications for understanding the pathophysiology underlying apraxia of speech and other motor speech disorders

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    BACKGROUND : The complexity of speech motor control, and the incomplete conceptualisation of phases in the transformation of the speech code from linguistic symbols to a code amenable to a motor system, tend to obscure the understanding of acquired apraxia of speech (AOS). The four-level framework (FLF) of speech sensorimotor control suggests the differentiation between speech motor planning, programming and execution and locate the locus of disruption in AOS in the motor planning phase. Currently, terminological confusion and uncertainty regarding phases in speech motor control still complicate the characterisation of AOS. This neuromotor disorder is inconsistently described in the literature as a “planning or programming”, “planning and programming”, or as a “planning and/or programming” disorder. PURPOSE : To describe a new version of the FLF, the FL (four-level) model, which further explicates and differentiates between speech motor planning, programming, and execution levels or phases of processing; to integrate concepts from computational modelling into the FL model and propose distinct control architectures for both the planning and programming levels; and to identify the loci and nature of disruption in the motor planning phase which could explain the pathophysiology and core features of AOS. DISCUSSION AND CONCLUSIONS : A four-level model is presented that differentiates two pre-execution phases and an execution phase. The first pre-execution phase is controlled by a motor planner and involves an inverse model, an efference copy, and a forward model for each sound or over-learnt utterance. This phase also involves a forward predictive planner which enables the system to handle the planning of several sounds and to plan coarticulation of sounds. The motor planner is operated according to an auxiliary forward model architecture. AOS is depicted as a breakdown at several possible points in the motor planning phase. The second pre-execution phase is driven by a motor program generator and predictive controller that is governed by an integral forward model architecture. The final execution phase is portrayed as being driven by closed loop control. The conceptualization of the programmer challenges the traditional view of execution and not only that of planning as is generally accepted. The implications for the classification of motor speech disorders are discussed. Future research should address the exact nature of articulatory movements and other features of speech across the range of planning, pure programming, programming-execution and pure execution disorders.https://www.tandfonline.com/loi/paph202021-05-21hj2020Speech-Language Pathology and Audiolog
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