Vocal production and auditory learning in the genus Chlorocebus

Chlorocebus 属的发声和听觉学习

• 批准号: 428036558
• 负责人: Professorin Dr. Julia Fischer
• 金额: --
• 依托单位: Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung (DPZ)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/428036558?language=en
• 关键词: Vocal; production; auditory; learning; genus

The human language faculty provides our species with exceptional means of communication that are unparalleled in the animal kingdom. Much research effort has been devoted to shed light on evolutionary precursors to linguistic abilities in nonhuman primates. With regard to the vocal-auditory domain, it is well established that the acoustic structure of nonhuman primate vocalizations is largely hard-wired, while call usage is more flexible. On the recipients’ side, auditory learning is crucial to establish what specific calls stand for. Yet, important gaps in understanding remain. First, in light of the restricted call structure, it has been proposed that critical information may be encoded in the composition of the call sequences. Previous attempts to characterize the structure of such sequences made the assumption that calls can be clearly assigned to specific categories although most nonhuman primate vocal repertoires are highly graded. Moreover, these attempts considered the entire sequence to assign it to a specific context, which does not seem adaptive given that listeners are forced to make rapid decisions in predator contexts. We will develop a biologically grounded computational Bayesian perception and decision-model that takes into account the uncertainty with which calls can be assigned to different contexts to provide a lean account of monkeys’ responses to calls. Second, there is ample evidence that calls vary in relation to the context in which they are given, but it is not yet clear which factors specifically drive the variation in call structure. The second aim of this proposal is to examine the degree to which stimulus type, stimulus location, and experience with a stimulus affect call structure, to shed light on how monkeys categorize different kinds of danger and how this in turn affects their communication. Third, our previous work has shown that monkeys are able to attach meaning to sounds after single exposure to a threatening stimulus in the wild. This observation stands in stark contrast to the difficulties that nonhuman primates reveal when tested in auditory discrimination tasks in operant conditioning settings. We will test the conjecture that the valence of the stimulus strongly affects the learning trajectory by conducting field experiments to assess how rapidly the monkeys learn to distinguish different sounds in predator and food contexts. We will use the alarm call system in the genus Chlorocebus. The computational model will be specified based on existing acoustic analyses on the graded structure of vocalizations in this genus; field experiments will be conducted in Senegal and at two sites in South Africa on a total of 11 social groups of green monkeys and vervets. With this research, we aim to contribute to a better understanding of the principles characterizing nonhuman primate communication.

人类的语言能力为我们这个物种提供了在动物王国中无与伦比的特殊交流方式。许多研究工作都致力于揭示非人类灵长类动物语言能力的进化前兆。关于声音-听觉领域，非人类灵长类动物发声的声学结构在很大程度上是硬连接的，而呼叫使用则更加灵活。在接受者方面，听觉学习对于确定特定呼叫的含义至关重要。然而，在理解上仍然存在重要的差距。首先，考虑到有限的呼叫结构，有人提出关键信息可以在呼叫序列的组成中进行编码。尽管大多数非人类灵长类动物的声音都是高度分级的，但之前对这种序列结构进行表征的尝试假设，叫声可以明确地分配到特定的类别。此外，这些尝试考虑了整个序列，将其分配到特定的环境中，这似乎不适应，因为听众在捕食者的环境中被迫做出快速决定。我们将开发一个基于生物学的计算贝叶斯感知和决策模型，该模型考虑到呼叫可以分配到不同上下文的不确定性，以提供猴子对呼叫反应的精简说明。其次，有充分的证据表明，呼叫因其所处的环境而异，但尚不清楚是哪些因素具体驱动了呼叫结构的变化。这项研究的第二个目的是研究刺激类型、刺激位置和刺激经历对呼叫结构的影响程度，从而揭示猴子如何对不同种类的危险进行分类，以及这反过来又如何影响它们的交流。第三，我们之前的研究表明，猴子在野外受到一次威胁刺激后，能够将声音的含义附加到声音上。这一观察结果与非人类灵长类动物在操作性条件反射环境下的听觉辨别任务中所表现出的困难形成鲜明对比。我们将通过实地实验来评估猴子在捕食者和食物环境中学习区分不同声音的速度，从而测试刺激的效价强烈影响学习轨迹的猜想。我们将使用绿尾草属的报警呼叫系统。计算模型将根据现有的声学分析来指定该属的分级发声结构；将在塞内加尔和南非的两个地点对总共11个社会群体的绿猴和黑尾猴进行实地实验。通过这项研究，我们的目标是有助于更好地理解非人灵长类动物交流的原则。