A quick correction mechanism of the tongue has been formerly experimentally observed in speech posture stabilization in response to a sudden tongue stretch perturbation. Given its relatively short latency (< 150 ms), the response could be driven by somatosensory feedback alone. The current study assessed this hypothesis by examining whether this response is induced in the absence of auditory feedback.
View Article and Find Full Text PDFThe interaction of rarefied gases with functionalized surfaces is of great importance in technical applications such as gas separation membranes and catalysis. To investigate the influence of functionalization and rarefaction on gas flow rate in a defined geometry, pressure-driven gas flow experiments with helium and carbon dioxide through plain and alkyl-functionalized microchannels are performed. The experiments cover Knudsen numbers from 0.
View Article and Find Full Text PDFAlthough there is no doubt from an empirical viewpoint that reflex mechanisms can contribute to tongue motor control in humans, there is limited neurophysiological evidence to support this idea. Previous results failing to observe any tonic stretch reflex in the tongue had reduced the likelihood of a reflex contribution in tongue motor control. The current study presents experimental evidence of a human tongue reflex in response to a sudden stretch while holding a posture for speech.
View Article and Find Full Text PDFAs part of a long-term research project aiming at generating a biomechanical model of a fossil human tongue from a carefully designed 3D Finite Element mesh of a living human tongue, we present a computer-based method that optimally registers 3D CT images of the head and neck of the living human into similar images of another primate. We quantitatively evaluate the method on a baboon. The method generates a geometric deformation field which is used to build up a 3D Finite Element mesh of the baboon tongue.
View Article and Find Full Text PDFAs a functional component of erythrocyte hemoglobin, iron is essential for oxygen delivery to all tissues in the body. The liver-derived peptide hepcidin is the master regulator of iron homeostasis. During anemia, the erythroid hormone erythroferrone regulates hepcidin synthesis to ensure the adequate supply of iron to the bone marrow for red blood cell production.
View Article and Find Full Text PDFWe present a calibration system called Dried Water Column (DWC). It applies pressure on a sensor with a latex finger filled with water, which pressure is controlled with a water column. This is intended to mimic the way the deformable tongue mechanically interacts with the hard palate.
View Article and Find Full Text PDFSkeletal muscle modeling has a vital role in movement studies and the development of therapeutic approaches. In the current study, a Huxley-based model for skeletal muscle is proposed, which demonstrates the impact of impairments in muscle characteristics. This model focuses on three identified ions: H, inorganic phosphate P, and Ca.
View Article and Find Full Text PDFIn order to study the local interactions between facial soft-tissues and a Silhouette Soft suspension suture, a CE marked medical device designed for the repositioning of soft tissues in the face and the neck, Finite element simulations were run, in which a model of the suture was embedded in a three-layer Finite Element structure that accounts for the local mechanical organization of human facial soft tissues. A 2D axisymmetric model of the local interactions was designed in ANSYS, in which the geometry of the tissue, the boundary conditions and the applied loadings were considered to locally mimic those of human face soft tissue constrained by the suture in facial tissue repositioning. The Silhouette Soft suture is composed of a knotted thread and sliding cones that are anchored in the tissue.
View Article and Find Full Text PDFIn a study of whether somatosensory feedback related to articulatory configuration is involved in speech perception, 30 French-speaking adults performed a speech discrimination task in which vowel pairs along the French /u/ (rounded vowel requiring a small lip area) to /œ/ (rounded vowel associated with larger lip area) continuum were used as stimuli. Listeners had to perform the test in two conditions: with a 2-cm-diameter lip-tube in place (mimicking /œ/) and without the lip-tube (neutral lip position). Results show that, in the lip-tube condition, listeners perceived more stimuli as /œ/, in line with the proposal that an auditory-somatosensory interaction exists.
View Article and Find Full Text PDFUnlabelled: As a functional component of erythrocyte hemoglobin, iron is essential for oxygen delivery to all tissues in the body. The liver-derived peptide hepcidin is the master regulator of iron homeostasis. During anemia, the erythroid hormone erythroferrone regulates hepcidin synthesis to ensure adequate supply of iron to the bone marrow for red blood cells production.
View Article and Find Full Text PDFWilful movement requires neural control. Commonly, neural computations are thought to generate motor commands that bring the musculoskeletal system - that is, the plant - from its current physical state into a desired physical state. The current state can be estimated from past motor commands and from sensory information.
View Article and Find Full Text PDFObjectives: The study aims to better understand the rhythmic abilities of people who stutter and to identify which processes potentially are impaired in this population: (1) beat perception and reproduction; (2) the execution of movements, in particular their initiation; (3) sensorimotor integration.
Material And Method: Finger tapping behavior of 16 adults who stutter (PWS) was compared with that of 16 matching controls (PNS) in five rhythmic tasks of various complexity: three synchronization tasks - a simple 1:1 isochronous pattern, a complex non-isochronous pattern, and a 4 tap:1 beat isochronous pattern -, a reaction task to an aperiodic and unpredictable pattern, and a reproduction task of an isochronous pattern after passively listening.
Results: PWS were able to reproduce an isochronous pattern on their own, without external auditory stimuli, with similar accuracy as PNS, but with increased variability.
Language processing is a highly integrative function, intertwining linguistic operations (processing the language code intentionally used for communication) and extra-linguistic processes (e.g., attention monitoring, predictive inference, long-term memory).
View Article and Find Full Text PDFObjectives: The mechanical interactions between tongue and palate are crucial for speech production and swallowing. In this study, we presented examples of pressure signals that can be recorded with our PRESLA system (PRESLA holds for the French expression "PRESsion de la LAngue" [Pressure from the tongue]) to assess these motor functions, and we illustrate which issues can be tackled with such a system.
Materials And Methods: A single French-speaking edentulous subject, old wearer of a complete denture, with no speech production and swallowing disorders, was recorded during the production of nonsense words including French alveolar fricatives, and during dry and water swallowing.
Comput Methods Programs Biomed
January 2021
Background And Objectives: This paper presents the results of a Machine-Learning based Model Order Reduction (MOR) method applied to a complex 3D Finite Element (FE) biomechanical model of the human tongue, in order to create a Digital Twin Model (DTM) that enables real-time simulations. The DTM is designed for future inclusion in a computer assisted protocol for tongue surgery planning.
Methods: The proposed method uses an "a posteriori" MOR that allows, from a limited number of simulations with the FE model, to predict in real time mechanical responses of the human tongue to muscle activations.
Recent studies on the remediation of speech disorders suggest that providing visual information of speech articulators may contribute to improve speech production. In this study, we evaluate the effectiveness of an illustration-based rehabilitation method on speech recovery of a patient with non-fluent chronic aphasia. The software allowed visualization by the patient of reference tongue and lip movements recorded using ultrasound and video imaging.
View Article and Find Full Text PDFRecombinant erythropoietin (EPO) and iron substitution are a standard of care for treatment of anemias associated with chronic inflammation, including anemia of chronic kidney disease. A black box warning for EPO therapy and concerns about negative side effects related to high-dose iron supplementation as well as the significant proportion of patients becoming EPO resistant over time explains the medical need to define novel strategies to ameliorate anemia of chronic disease (ACD). As hepcidin is central to the iron-restrictive phenotype in ACD, therapeutic approaches targeting hepcidin were recently developed.
View Article and Find Full Text PDFThe human tongue is atypical as a motor system since its movement is determined by deforming its soft tissues via muscles that are in large part embedded in it (muscular hydrostats). However, the neurophysiological mechanisms enabling fine tongue motor control are not well understood. We investigated sensorimotor control mechanisms of the tongue through a perturbation experiment.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2020
Auditory speech perception enables listeners to access phonological categories from speech sounds. During speech production and speech motor learning, speakers' experience matched auditory and somatosensory input. Accordingly, access to phonetic units might also be provided by somatosensory information.
View Article and Find Full Text PDFExperimental studies of speech production involving compensations for auditory and somatosensory perturbations and adaptation after training suggest that both types of sensory information are considered to plan and monitor speech production. Interestingly, individual sensory preferences have been observed in this context: subjects who compensate less for somatosensory perturbations compensate more for auditory perturbations, and . We propose to integrate this sensory preference phenomenon in a model of speech motor planning using a probabilistic model in which speech units are characterized both in auditory and somatosensory terms.
View Article and Find Full Text PDFInner speech has been shown to vary in form along several dimensions. Along condensation, condensed inner speech forms have been described, that are supposed to be deprived of acoustic, phonological and even syntactic qualities. Expanded forms, on the other extreme, display articulatory and auditory properties.
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