Doctoral Dissertation Research: Evolutionary biomechanics of the human hyolingual apparatus

博士论文研究：人类舌舌器的进化生物力学

• 批准号: 1732175
• 负责人: Callum Ross
• 金额: $ 2.2万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1732175&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Evolutionary; biomechanics

The human tongue and hyoid bone have been extensively studied for their role in the evolution of speech. Some researchers hypothesize that our unique tongue and hyoid morphology also makes us more prone to choking. This research uses advanced imaging techniques and computational modeling to test whether human hyolingual morphology is beneficial or detrimental for swallowing. While this research focuses on swallowing function in an evolutionary context, the findings of this research will also advance our understanding of normal swallowing mechanisms and therefore may have clinical applications. The software for the computational model generated by this project will be made freely available upon completion. This project provides mentored research not only to a woman in science but specifically one studying biomechanics, a field in which women are underrepresented. Furthermore, the project will support undergraduate research and training for a diverse group of students at the University of Chicago.The short faces and low tongue, hyoid, and larynx of humans have been argued to be adapted for speech and maladapted for swallowing. Recent studies cast doubt on both of these claims, prompting further exploration of alternative hypotheses to explain the origin of the uniquely human hyolingual apparatus. This project tests the hypothesis that hyolingual biomechanics constrain morphology, specifically that a low hyolingual apparatus is necessary to maintain swallowing performance as the face becomes shorter. X-ray Reconstruction of Moving Morphology (XROMM), diffusible iodine-based contrast-enhanced CT (diceCT), and electromyography (EMG) will be used to obtain high spatiotemporal resolution in vivo measurements of bone, tongue, and muscle biomechanics, including hyolingual muscle length, velocity, and activity in a primate model system. These data will then be used to validate a computational model of the impacts on swallowing biomechanics and performance of variation in hyolingual position, and craniofacial morphology. Falsification of the constraint hypothesis would provide indirect support for the hypothesis that the morphology of the human vocal tract is the result of natural selection for speech performance. This project will inform future research on how the functional requirements of the hyolingual apparatus may have influenced the morphology of surrounding structures, e.g., the mandibular symphysis, in both extant and extinct taxa.

人类舌头和舌骨在言语进化中的作用已被广泛研究。一些研究人员推测，我们独特的舌头和舌骨形态也使我们更容易窒息。这项研究使用先进的成像技术和计算模型来测试人类舌舌形态对吞咽是否有益或有害。虽然这项研究的重点是进化背景下的吞咽功能，但这项研究的结果也将增进我们对正常吞咽机制的理解，因此可能具有临床应用。该项目生成的计算模型的软件将在完成后免费提供。该项目不仅为科学领域的女性提供指导性研究，还特别为研究生物力学的女性提供指导，而生物力学是女性代表性不足的领域。此外，该项目还将支持芝加哥大学不同学生群体的本科生研究和培训。人类的短脸和低舌头、舌骨和喉部被认为适合说话，但不适合吞咽。最近的研究对这两种说法提出了质疑，促使人们进一步探索替代假设，以解释人类独特的舌舌器官的起源。该项目测试了舌舌生物力学限制形态的假设，特别是当面部变短时，需要较低的舌舌装置来维持吞咽性能。移动形态学 X 射线重建 (XROMM)、弥散碘对比增强 CT (diceCT) 和肌电图 (EMG) 将用于获得骨、舌头和肌肉生物力学的高时空分辨率体内测量，包括灵长类动物模型系统中的舌舌肌长度、速度和活动。然后，这些数据将用于验证吞咽生物力学和舌舌位置变化以及颅面形态变化对吞咽生物力学的影响的计算模型。约束假设的证伪将为以下假设提供间接支持：人类声道的形态是言语表现自然选择的结果。该项目将为未来的研究提供信息，了解舌舌器的功能要求如何影响现存和灭绝类群中周围结构（例如下颌联合）的形态。