Doctoral Dissertation Improvement: Neural Substrates of Primate Communication: A Comparative Study of Facial and Hypoglossal Nuclei

灵长类动物在社交伙伴之间的交流中使用不同的感觉通道，从环尾狐猴辛辣的“洗尿”，到格拉达狒狒华丽的“翻唇”手势，再到人类说话的复杂节奏。这些信号通常是非常细微的，并以灵活的、上下文敏感的方式产生。由于神经系统在交流行为的计划和执行中起着核心作用，人们可以预料到，为交流提供辅助的大脑结构存在显著的物种差异。然而，到目前为止，人们对大脑控制口面部系统的物种差异知之甚少，口面部系统对面部表情和发声的产生如此重要。这个研究项目将有助于我们了解灵长类动物交流进化过程中两个重要转变的神经基础：(1)在类人猿和人类中更主要地使用面部表情，(2)熟练地使用舌头和嘴唇来服务于人类口语。在一个包括新大陆猴子、东半球猴子、猿猴和人类的样本中，直接供应面部表情肌肉和舌头的脑干区域将被分析，以揭示它们的化学成分和细胞结构。这项研究的结果将有助于阐明神经组织如何确定特定物种的交流信号，包括人类的语音，并将为灵长类大脑的进化提供见解

Primates use diverse sensory channels in their communication among social partners, ranging from the pungent "urine washing" of ring-tailed lemurs to the flamboyant "lip flip" gesture of gelada baboons to the complex rhythms of human speech. These signals are often highly nuanced and produced in a flexible, context-sensitive manner. Since the nervous system has a central role in the planning and execution of communicative behavior, one would expect significant species differences in the brain structures that subserve communication. To date, however, little is known about species differences in the brain's control of the orofacial system that is so vital to the production of facial expression and vocalization. This research project will contribute to our knowledge of the neural substrates underlying two important transformations in the evolution of primate communication: (1) the more dominant use of facial expressions among great apes and humans, and (2) the skilled use of the tongue and lips in the service of human spoken language. In a sample that includes New World monkeys, Old World monkeys, apes, and humans, brainstem regions that directly supply the muscles of facial expression and the tongue will be analyzed using techniques to reveal their chemical composition and cellular structure. The results of this study will help to clarify how neural organization determines species-specific communicative signals, including human speech, and will provide insights into the evolution of the primate brain