The role of motor systems on the functional neural organisation of language processing: Cross-linguistic evidence from sign and speech

背景：言语加工理论认为不同的特征是语言加工的关键决定因素。生成语法认为语法信息驱动言语感知[1]，而言语感知的运动理论认为语言感知涉及对言语产生网络的访问。参与运动产生的大脑区域与对有意义的行为（包括言语）的感知之间的密切联系已经得到了明确的确立。对于言语感知，语法以及感知和产生之间的潜在联系都是混乱的-因为言语通过单一的发音器官（嘴）连续地传达语法信息。然而，手语（SL）是由多个发音器官产生的-手，嘴，头，这些都在独立的皮层控制下。目的：本研究将采用神经影像学（功能磁共振成像，fMRI）和神经刺激（运动诱发电位，MEP，经颅磁刺激，TMS）相结合的综合神经科学方法，系统地探讨发音对英国手语（BSL）聋人母语手语者语言处理功能组织的影响。我们将在英语听力发言者中进行平行研究，其中感兴趣的问题在语言结构中是允许的，以获得语言感知运动系统的跨语言方法。研究方法：功能磁共振成像将被用来探讨感知语言发音对词汇和语法处理的影响，通过检查激活模式的签名者，因为他们处理不同的签署句法结构，如否定，这可以实现单独的非手动标记（摇头），或由共同延伸的非手动和手动标记。第二项研究将集中在听力非签名者处理视听（AV）英语对比AV句子与非强制性的面部动作。这些发现将提供有关运动和语法系统如何相互作用的信息。神经刺激将被用来检查相关的皮层区域之间的关系，通过记录MEP响应于单脉冲的手和嘴部区域的前运动皮层在聋人手语观看语言使用不同的发音，并建立运动生产和语言感知之间的因果关系，使用TMS。包括非语言的嘴和手的动作将使我们能够评估这些影响的领域特异性。在听力非签名者观看相同材料的平行实验将使我们能够分离由于发音运动（手>嘴）和语言知识（聋人参与者的手语和语音阅读，听力参与者的语音只读）的大小和轨迹的影响。同时进行的行为测量可以提供对这些神经成像和TMS数据的个体差异的深入了解。时间表：第1年-fMRI-BSL研究和BSL 1级，第2年-fMRI-AV & MEP-BSL研究和BSL 2级，第3年-MEP-AV & TMS-BSL研究，第4年TMS-AV研究影响：这项研究将为我们理解语言处理的皮层组织做出重大贡献，并最终为语言处理的发展提供信息。语言障碍的治疗干预（例如，失语症）。此外，该项目的工作将通过获得fMRI，MEP和TMS技术的专业知识来发展学生的学术生涯，并将建立（或继续）在高影响力，同行评审期刊上发表的高质量论文的良好记录。

Background: Theories of speech processing suggest different features as the crucial determinants of language processing. Generative grammar suggests that grammatical information drives speech perception [1] whereas the motor theory of speech perception proposes that language perception involves access to the speech production network. Close links between brain areas involved in motor production and the perception of meaningful actions, including speech, have been clearly established. For speech perception, both grammar and the potential connection between perception and production are confounded - as speech conveys grammatical information serially via a single articulator (mouth). However, signed languages (SLs), are produced by multiple articulators -- hands, mouth, head, which are under independent cortical control. Objectives: This project will use an integrative neuroscience approach combining neuroimaging (functional magnetic resonance imaging, fMRI) and neurostimulation (motor evoked potentials, MEP, transcranial magnetic stimulation, TMS) to systematically explore the articulatory effects on the functional organisation of language processing in deaf native signers of British Sign Language (BSL). We will conduct parallel studies in hearing speakers of English where the questions of interest are permissible within the language structure, in order to gain a cross-linguistic approach to the motor systems in language perception. Methods: FMRI will be used to explore the effects of the perceived language articulator on lexical and grammatical processing by examining the patterns of activation in signers as they process different signed syntactic structures such as negation, which can be realised solely by non-manual markers (headshake), or by coextensive non-manual and manual markers. A second study will focus on hearing non-signers processing audio-visual (AV) English to contrast AV sentences with non-obligatory facial actions. The findings will provide information about how the motor and grammatical systems may interact. Neurostimulation will be used to examine the relationship between the relevant cortical areas by recording MEPs in response to single pulses to the hand and mouth regions of premotor cortex in deaf signers viewing language produced using different articulators and to establish the causal link between motor production and language perception using TMS. Including non-linguistic mouth and hand actions will allow us to assess the domain specificity of these effects. A parallel experiment in hearing non-signers viewing the same materials will allow us to separate the effects due to size and trajectory of articulatory movement (hand > mouth) and language knowledge (sign and speech reading in deaf participants, speech reading-only in hearing participants). Concurrent behavioural measures may offer insight into individual variability in these neuroimaging and TMS data.Schedule: Year1 -fMRI-BSL study and BSL Level 1, Year2 -fMRI-AV & MEP-BSL studies and BSL Level 2, Year3 -MEP-AV & TMS-BSL studies , Year4 TMS-AV study Impact: This research will provide a major contribution to our understanding of the cortical organisation of language processing as well ultimately informing the development of therapeutic interventions for language impairment (e.g., aphasia). In addition, working on the project will develop the student's academic career through gaining expertise in fMRI, MEP and TMS techniques, and will establish (or continue) a strong record of high quality papers published in high impact, peer-reviewed journals.