Integrative Studies of Development and Function of Vocalizations

鸟鸣被广泛认为是研究学习的生物学基础的模式系统。它的地位源于歌曲交流和人类语言之间的许多惊人的相似之处，以及最近关于歌曲学习背后的大脑机制的发现。事实上，鸟鸣已经成为学习神经生物学研究的主要脊椎动物模型。比彻博士将利用实地和实验室研究来研究一种具有代表性的物种--歌雀--的歌唱学习能力。现场视角对于理解歌曲学习过程至关重要，因为比彻博士在现场发现的歌曲学习“规则”与实验室研究得出的规则大相径庭。比彻博士将尝试通过实验室和实地研究相结合的方式来解决这一差异。这种差异的解决对于有效地利用鸟鸣作为模型系统至关重要，因为如果我们对歌唱学习的理解一开始就不完整或不正确，我们就不能指望研究出歌唱学习的神经生物学。在实验室里，比彻博士将直接测试他长期实地研究得出的有关歌曲学习的假设。关键的一点是，到目前为止，这些假说中的每一个要么没有被实验室研究表明，要么实际上是相反的。(1)幼鸟复制特定年长个体或“家教”的整个歌声(他没有发展出交叉家教的混合歌声)。(2)他从所有接触到他的导师那里学到一些歌曲。(3)如果两个或两个以上的导师唱同一歌曲类型的不同版本，幼鸟会结合这两个版本。(4)优先学习两个或两个以上导师共享的类型。(5)歌曲学习的关键时期远远超出了实验室研究中确定的“古典”时期。比彻博士将尝试通过实验室实验来验证这些结论，在这些实验中，他模拟了野外发生的基本条件(包括：鸟儿听到的是实况家教，而不是磁带，在关键时期，他会按顺序与家教接触，他可以与家教进行社交互动)。比彻博士还将继续进行歌曲感知的实验室实验，以期将这些结果与越来越多的关于大脑中歌曲中枢功能的知识联系起来。最后，他将对歌曲学习的自然语境进行进一步的田野研究。

Bird song is widely recognized as a model system for investigation into the biological basis of learning. Its status derives from the many striking parallels between song communication and human language and the recent discoveries concerning brain mechanisms underlying song learning. Indeed, bird song has become the major vertebrate model for the study of the neurobiology of learning. Dr. Beecher will use both field and laboratory studies to examine song learning in one representative species, the song sparrow. The field perspective is crucial for understanding the song learning process, because the "rules" of song learning that Dr. Beecher has discovered in the field turn out to be quite different from the rules that had been inferred from laboratory studies. Dr. Beecher will try to resolve this discrepancy through a combination of laboratory and field studies. Resolution of the discrepancy is crucial to the effective use of bird song as a model system, for we cannot hope to work out the neurobiology of song learning if our understanding of song learning is incomplete or incorrect to begin with. In the laboratory, Dr. Beecher will directly test hypotheses concerning song learning derived from his long-term field study. The key point is that each of these hypotheses is either not indicated or actually contra-indicated by laboratory studies to date. (1) The young bird copies whole songs of particular older individuals or "tutors" (he develops no cross- tutor hybrid songs). (2) He learns some songs from all tutors to whom he is exposed. (3) If two or more tutors sing different versions of the same song type, the young bird combines these. (4) Types shared by two or more tutors are preferentially learned. (5) The critical period for song learning extends well beyond the "classical" period identified in laboratory studies. Dr. Beecher will try to validate these conclusions by laboratory experiments in which he simulates the essential conditions that occur in the field (including: the bird hears live tutors, not tapes, he is exposed to the tutors sequentially during the critical period, and he can socially interact with his tutors). Dr. Beecher also will continue laboratory experiments on song perception, with a particular view to relating these results to the increasing body of knowledge concerning the function of song centers in the brain. Finally, he will carry out further field studies on the natural context of song learning.