Genetic And Experiential Influences On The Development Of Primate Vocal Behavior

这和一个同伴项目（Z01 HD001123）研究灵长类动物的听觉交流。这些研究的总体目标是从发育、神经机制、内分泌因素和社会环境等方面全面了解灵长类动物的听觉交流。松鼠猴和普通狨猴这两个物种是研究的主要对象，并在适当情况下从其他物种收集额外数据。本项目从生物声学和行为学的角度研究灵长类动物的交流，重点研究自然环境下发声的详细声学结构，以及结构差异与年龄、性别、经验和反应选择性差异的关系，以及社会环境和遗传背景等更广泛的因素。该项目之前的工作已经确定，婴儿哭声的详细声学结构存在相当大的个体差异，至少在生命的前3个月是稳定的。该项目还证明，y型迷宫模式可以成功地评估具有不同经验的老年人对活婴儿或婴儿哭声录音的反应性。今年的其他实验表明，大约三分之一的试验，无论是使用活婴儿还是录制的哭声，都能从有经验的父母那里得到积极的反应（接近声源）。另一项新的研究解决了使用最有效的方法来收集婴儿的声音数据的问题，这些婴儿短暂地与他们的家庭群体分开，目的是记录他们的声音。我们实验室先前的工作使用了非常短的分离时间，5分钟，用于此目的。然而，尚不清楚在这短时间内产生的发声是否反映了婴儿的发育状态，还是反映了对分离的短期情绪反应。因此，对6名婴儿进行了更长时间（20分钟）的分离，并分析了他们的发声。研究发现，在分离的前5分钟和最后5分钟，它们发出的声音的频率和类型都没有显著差异。这表明，5分钟的分离期足以表征婴儿发声行为的发育阶段。反过来，这意味着我们可以继续利用压力较小、分离时间较短的时间来实现这一目的。

This and a companion project (Z01 HD001123) investigate auditory communication in primates. The overall goal of these studies is to provide a comprehensive understanding of primate auditory communication in terms of development, neural mechanisms, endocrine factors, and social context. Two species, the squirrel monkey and the common marmoset, are the main subjects of study, with additional data collected from other species where appropriate. The present project studies primate communication from a bioacoustic and ethological perspective, focusing on the detailed acoustic structure of vocalizations produced in natural settings, and the relationship of structural differences to differences in age, gender, experience and response selectivity, as well as the broader factors of social context and genetic background. Prior work in this project has determined that there is considerable individual variation in the detailed acoustic structure of infant cries, which is stable over at least the first 3 months of life. The project has also demonstrated that a Y-maze paradigm successfully permits evaluating the responsiveness of older individuals with varying experience to live infants or to recordings of infant crying. Additional experiments this year have shown that about one-third of trials, using either live infants or recorded cries, result in positive responses (approaching the sound source) from parentally experienced individuals. Another new study addressed the issue of using the most efficient method to collect vocal data from infants briefly separated from their family group for the purpose of recording their vocalizations. Prior work in our laboratory had used a very short separation time, 5 minutes, for this purpose. However, it was unclear whether the vocalizations produced during this short time period reflected the developmental state of the infant or were a reflection of a short-term emotional response to the separation. Therefore, six infants were separated for a longer period, 20 minutes, and their vocalizations analyzed. It was found that there were no significant differences in either the rate or the type of vocalizations produced in the first 5 minutes and last 5 minutes of the separation. This suggests that a 5-minute separation period is sufficient to characterize the developmental stage of an infants vocal behavior. This, in turn, means that we can continue using the less stressful, shorter separation period for this purpose. A detailed analysis of the infant cries of prosimian primates was completed this year. Prosimians are of interest because of the long period of separation from other primate groups evolutionarily, and the fact that several prosimians are active nocturnally. It was found that the infant cries of bushbabies are click-like in structure, very different from the tonal cries of simian primates. Furthermore, the cries of several diurnal lemurs differ in some respects from the tonal cries of simian primates. This variety of cry acoustics suggests that prosimians, being the earliest primate line, may have experimented with different types of cries. It would be of interest to investigate the laryngeal structure of these prosimians and compare them with the larynges of simian primates, as this may give important clues on the differences in cry production across the primates as a whole.