Posture in oromotor control

姿势是一种基本的运动行为，是自愿运动的前兆(Ting，2007)。即使是伸手这样的基本动作也需要控制头部和躯干的姿势(Soechting&Flanders，1991)。达成对姿势的普遍理解的部分问题是，文献几乎只关注头部、躯干和四肢。目前尚不清楚为这些大型结构的姿势提出的控制范例是否同样适用于身体的其他区域。这项拟议的研究旨在提高我们对口部姿势的理解，口部是呼吸、进食、吞咽、面部表情和言语等重要功能的发源地。例如，虽然研究重力对姿势的影响有很长的传统(Ivanenko&Gurfinkel，2008)，但在机动系统中，重力对姿势的影响在很大程度上被忽视了。从远征35号太空任务归来后，宇航员克里斯·哈德菲尔德报告说：我能感觉到嘴唇和舌头的重量，不得不改变我说话的方式。我没有意识到我已经学会了用失重的舌头说话。(https://www.npr.org/2013/05/18/184821421/).)通过明确地将姿势建模为口腔运动行为的基本基础，我们正在建立一个新的研究方向，有望加深我们对口腔运动控制的理解，以及对姿势的总体理解。我们提出了一系列分两个阶段的三个研究集。第一阶段的研究将包括对现有数据集的计算机模拟和分析，这些研究可以在实验室设施因新冠肺炎而关闭的情况下远程进行。第二阶段的研究包括使用口腔内视频、超声波成像和肌电图仪的实验室实验。本研究围绕三个研究问题展开。首先，口腔姿势是如何受外界干扰影响的？我们研究重力的变化如何系统地改变宇航员的语音，以及舌头姿势如何适应咬合块的扰动降低舌头和下巴。其次，口腔姿势是否“在没有运动的情况下仍然保持活跃”(Martin，1977)？我们检查舌头和舌膜的姿势行为，后者负责在呼吸、吞咽和说话过程中打开和关闭鼻腔。最后，口腔姿势是如何受到来自同步语音动作的内部扰动的影响？我们调查了表情姿势(例如，微笑)如何对语音中相互冲突的短暂嘴唇动作做出反应。除了在生物医学工程、运动控制、感觉-运动整合和认知/意识的具体模型等领域发展理论外，我们改进的人类口腔运动系统模型还将影响应用领域，如外科计划和康复、机器人、语言教学和学习、计算机动画以及吞咽障碍和语言发育和下降的临床干预。

Posture is a fundamental motor behaviour, and is a precursor to voluntary movements (Ting, 2007). Even basic movements such as reaching require control of head and trunk posture (Soechting & Flanders, 1991). Part of the problem in arriving at a universal understanding of posture is that the literature has focused almost exclusively on the head, trunk and limbs. It is unknown whether the control paradigms that have been proposed for posture of these large structures apply equally to other regions of the body. The proposed research aims to improve our understanding of posture in the oral region, host to such vital functions as breathing, feeding, swallowing, facial expression and speech. For example, although there has been a long tradition of investigating the effects of gravity on posture (Ivanenko & Gurfinkel, 2008), gravitational effects on posture in oromotor systems has been largely overlooked. After returning from the Expedition 35 space mission, astronaut Chris Hadfield reported: "I could feel the weight of my lips and tongue and had to change how I was talking. I didn't realize I had learned to talk with a weightless tongue." (https://www.npr.org/2013/05/18/184821421/). By explicitly modeling posture as a fundamental basis of oromotor behaviour, we are establishing a new research direction that promises to further our understanding of oromotor control, and of posture in general. We propose a series of three study sets across two phases. Phase 1 studies will involve computer simulations and analyses of existing datasets, which can be carried out remotely while laboratory facilities are closed due to COVID-19. Phase 2 studies include laboratory experiments using intraoral video, ultrasound imaging and electromyography. The study sets focus on three research questions. Firstly, how are oral postures affected by external perturbations? We investigate how changes in gravity systematically change the speech of astronauts, and how tongue posture adapts in response to bite block perturbation lowering the tongue and jaw. Secondly, do oral postures remain "active [even] in the absence of movement" (Martin, 1977)? We examine postural behaviours of the tongue and velum, the latter of which is responsible for opening and closing the nasal cavity during breathing, swallowing, and speech. Lastly, how are oral postures affected by internal perturbations from synchronous speech movements? We investigate how expressive postures (e.g., smiling) respond to conflicting transient lip movements from speech. In addition to advancing theory in areas such as biomedical engineering, motor control, sensory-motor integration and embodied models of cognition/consciousness, our improved models of the human oromotor system will impact application areas such as surgical planning and rehabilitation, robotics, language teaching and learning, computer animation and clinical intervention in swallowing disorders and language development and decline.