3,969 research outputs found

    Magnetic resonance imaging of the brain and vocal tract:Applications to the study of speech production and language learning

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    The human vocal system is highly plastic, allowing for the flexible expression of language, mood and intentions. However, this plasticity is not stable throughout the life span, and it is well documented that adult learners encounter greater difficulty than children in acquiring the sounds of foreign languages. Researchers have used magnetic resonance imaging (MRI) to interrogate the neural substrates of vocal imitation and learning, and the correlates of individual differences in phonetic “talent”. In parallel, a growing body of work using MR technology to directly image the vocal tract in real time during speech has offered primarily descriptive accounts of phonetic variation within and across languages. In this paper, we review the contribution of neural MRI to our understanding of vocal learning, and give an overview of vocal tract imaging and its potential to inform the field. We propose methods by which our understanding of speech production and learning could be advanced through the combined measurement of articulation and brain activity using MRI – specifically, we describe a novel paradigm, developed in our laboratory, that uses both MRI techniques to for the first time map directly between neural, articulatory and acoustic data in the investigation of vocalisation. This non-invasive, multimodal imaging method could be used to track central and peripheral correlates of spoken language learning, and speech recovery in clinical settings, as well as provide insights into potential sites for targeted neural interventions

    A multispeaker dataset of raw and reconstructed speech production real-time MRI video and 3D volumetric images

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    Real-time magnetic resonance imaging (RT-MRI) of human speech production is enabling significant advances in speech science, linguistics, bio-inspired speech technology development, and clinical applications. Easy access to RT-MRI is however limited, and comprehensive datasets with broad access are needed to catalyze research across numerous domains. The imaging of the rapidly moving articulators and dynamic airway shaping during speech demands high spatio-temporal resolution and robust reconstruction methods. Further, while reconstructed images have been published, to-date there is no open dataset providing raw multi-coil RT-MRI data from an optimized speech production experimental setup. Such datasets could enable new and improved methods for dynamic image reconstruction, artifact correction, feature extraction, and direct extraction of linguistically-relevant biomarkers. The present dataset offers a unique corpus of 2D sagittal-view RT-MRI videos along with synchronized audio for 75 subjects performing linguistically motivated speech tasks, alongside the corresponding first-ever public domain raw RT-MRI data. The dataset also includes 3D volumetric vocal tract MRI during sustained speech sounds and high-resolution static anatomical T2-weighted upper airway MRI for each subject.Comment: 27 pages, 6 figures, 5 tables, submitted to Nature Scientific Dat

    Neuronal underpinnings of stuttering

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    Fluent speech production depends on robust connections between brain regions that are crucial for auditory processing, motor planning and execution. The ability of the speech apparatus to produce effortless, continuous and uninterrupted flow of speech is compromised in people who stutter (PWS). Stuttering is a multifactorial speech fluency disorder that results in unintended occurrences of sound syllable repetitions, prolongations, and blocks, particularly on the initial part of words and sentences. Decades of research on the topic have produced an extensive amount of data but the mechanism behind the symptoms associated with stuttering is not clear. The aim of the present study was to investigate the neuronal basis of stuttering by looking at the brains neurochemistry utilizing the proton magnetic resonance spectroscopy (1H - MRS) technique. In particular, we looked at the neurotransmitters N-acetyl Aspartate (NAA), an aggregate of Glutamate and Glutamine (Glx) and myo-inositol (mI) as potential candidates for understanding the biochemical manifestations of stuttering. We have also collected behavioral data from the PWS group and correlated it with their spectroscopy results. Finally, we combined the measurements of neuronal activity behind speech production, probed with functional magnetic resonance imaging (fMRI), with 1H-MRS measurements in order to achieve information on the interaction between neuronal activation and underlying neurochemical function. The inferior frontal gyrus (IFG) was chosen as a target region for this investigation, given its' involvement in speech motor control. Neurotransmitter mI showed the main group effect. The cerebral metabolite pattern of PWS is characterized by the pronounced reduction in myo-inositol level in the IFG. Myo- inositol is considered a glial marker and its concentration may reflect the condition of myelin in the brain. The myelination process is referred to as the maturation process of the fibers that facilitates rapid neural innervation of speech muscles underlying speech fluency. Hence, given the existing literature on the topic and our main findings we suggested that delayed or impaired myelination of the speech-related neuronal network in the postnatal period might be responsible for the later development of stuttering.Flytende tale er avhengig av solide forbindelser mellom hjerneområder involvert i auditorisk prosessering, motorisk planlegging og utførelse. Taleapparatets evne til uanstrengt å produsere flytende uforstyrret tale er forstyrret hos personer som stammer (PWS). Stamming er en sammensatt forstyrrelse av taleflyt som resulterer i ufrivillige gjentagelser av stavelser, utvidelser, og blokkeringer, spesielt i begynnelsen av ord og setninger. Gitt tiår med forskning på området er det ennå ikke klart hvilke mekanismer som ligger til grunn for stammingen. Hensikten med dette studiet har vært å utforske det nevrale grunnlaget til stamming ved å se på hjernens nevrokjemi ved å ta i bruk proton-magnetisk resonsansspektroskopi (1H-MRS) teknikk. Vi har sett på om nevrotransmitterene: N-acetyl Asparatate (NAA); glutamat og glutamin (Glx) og myo-inositol kan bidra til forståelsen av de biokjemiske manifestasjonene av stamming. Vi har også samlet inn atferdsdata fra PWS-gruppen og korrelert dette med spektroskopi-dataen. Til slutt kombinerte vi målingene av den nevral aktiviteten av taleproduksjon med 1H-MRS målingene for å se på interaksjon mellom nevral aktivering og underliggende nevrokjemisk funksjon. Inferior frontal gyrus (IFG) var målområdet for undersøkelsen, siden området er viktig for motorisk kontroll av tale. Nevrotransmitteren myo-inositol viste en hovedgruppeeffekt. Metabolittene i hjernen til personer som stammer var karakterisert av en tydelig reduksjon i nivå av myo-inositol i IFG. Myo-inositol er ansett som en glial markør, og dets konsentrasjon kan muligens fortelle om myelinets tilstand i hjernen. Myelineringsprosessen av nerveceller er en modningsprosess som fasiliterer rask signaloverføring fra hjernen til muskelfibrene involvert i tale. Vi foreslår derfor på bakgrunn av foreliggende litteratur på området og våre resultater at forsinket eller hemmet myelinering av tale-relaterte nevrale nettverk i spedbarnsperioden kan føre til senere utvikling av stamming.LOGO345MAPS-LOG0

    Perception of Words and Pitch Patterns in Song and Speech

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    This functional magnetic resonance imaging study examines shared and distinct cortical areas involved in the auditory perception of song and speech at the level of their underlying constituents: words and pitch patterns. Univariate and multivariate analyses were performed to isolate the neural correlates of the word- and pitch-based discrimination between song and speech, corrected for rhythmic differences in both. Therefore, six conditions, arranged in a subtractive hierarchy were created: sung sentences including words, pitch and rhythm; hummed speech prosody and song melody containing only pitch patterns and rhythm; and as a control the pure musical or speech rhythm. Systematic contrasts between these balanced conditions following their hierarchical organization showed a great overlap between song and speech at all levels in the bilateral temporal lobe, but suggested a differential role of the inferior frontal gyrus (IFG) and intraparietal sulcus (IPS) in processing song and speech. While the left IFG coded for spoken words and showed predominance over the right IFG in prosodic pitch processing, an opposite lateralization was found for pitch in song. The IPS showed sensitivity to discrete pitch relations in song as opposed to the gliding pitch in speech. Finally, the superior temporal gyrus and premotor cortex coded for general differences between words and pitch patterns, irrespective of whether they were sung or spoken. Thus, song and speech share many features which are reflected in a fundamental similarity of brain areas involved in their perception. However, fine-grained acoustic differences on word and pitch level are reflected in the IPS and the lateralized activity of the IFG

    Semantic radical consistency and character transparency effects in Chinese: an ERP study

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    BACKGROUND: This event-related potential (ERP) study aims to investigate the representation and temporal dynamics of Chinese orthography-to-semantics mappings by simultaneously manipulating character transparency and semantic radical consistency. Character components, referred to as radicals, make up the building blocks used dur...postprin

    Inner voice experiences during processing of direct and indirect speech

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    In this chapter, we review a new body of research on language processing, focusing particularly on the distinction between direct speech (e.g., Mary said, “This dress is absolutely beautiful!”) and indirect speech (e.g., Mary said that the dress was absolutely beautiful). First, we will discuss an important pragmatic distinction between the two reporting styles and highlight the consequences of this distinction for prosodic processing. While direct speech provides vivid demonstrations of the reported speech act (informing recipients about how something was said by another speaker), indirect speech is more descriptive of what was said by the reported speaker. This is clearly reflected in differential prosodic contours for the two reporting styles during speaking: Direct speech is typically delivered with a more variable and expressive prosody, whereas indirect speech tends to be used in combination with a more neutral and less expressive prosody. Next, we will introduce recent evidence in support of an “inner voice” during language comprehension, especially during silent reading of direct speech quotations. We present and discuss a coherent stream of research using a wide range of methods, including speech analysis, functional magnetic resonance imaging (fMRI), and eye-tracking. The findings are discussed in relation to overt (or ‘explicit’) prosodic characteristics that are likely to be observed when direct and indirect speech are used in spoken utterances (such as during oral reading). Indeed, the research we review here makes a convincing case for the hypothesis that recipients spontaneously activate voice-related mental representations during silent reading, and that such an “inner voice” is particularly pronounced when reading direct speech quotations (and much less so for indirect speech). The corresponding brain activation patterns, as well as correlations between silent and oral reading data, furthermore suggest that this “inner voice” during silent reading is related to the supra-segmental and temporal characteristics of actual speech. For ease of comparison, we shall dub this phenomenon of an “inner voice” (particularly during silent reading of direct speech) simulated implicit prosody to distinguish it from default implicit prosody that is commonly discussed in relation to syntactic ambiguity resolution. In the final part of this chapter, we will attempt to specify the relation between simulated and default implicit prosody. Based on the existing empirical data and our own theoretical conclusions, we will discuss the similarities and discrepancies between the two not necessarily mutually exclusive terms. We hope that our discussion will motivate a new surge of interdisciplinary research that will not only extend our knowledge of prosodic processes during reading, but could potentially unify the two phenomena in a single theoretical framework
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