NEURAL ANALYSIS OF VOCAL LEARNING

描述（改编自申请人的摘要）：长期目标是 了解学习和记忆的神经基础，特别是如何 大脑存储和呈现复杂的感官信息，以及它如何使用 感官信息来指导运动行为的学习。 声乐学习 songbirds为研究这些问题提供了一个有用的系统。 鸟类 在两个不同的阶段从成人“导师”那里学习歌曲， 取决于听觉体验和反馈。 第一，在关键时期， 对于感官学习，幼鸟听到导师的歌，并记住一个 这首歌的内部表示或“模板”。 那么在 在感觉运动学习期间，他们使用来自自己的听觉反馈， 声音逐渐完善他们的声音输出，使其符合存储的 tutor template 此外，鸟类有专门的大脑结构， 到歌曲学习，其中许多重要的神经变化可能是 发生。 最后，由于歌曲学习有一些特定的特点， 与语音获取一样，它可以提供对以下内容的特定洞察： 人类发声学习的机制和语言的关键期 发展 已知歌曲系统的前前脑（AF）通路发挥着重要作用。 在歌曲学习中起着重要作用，但其确切功能尚不清楚。 这条通路中的神经元对声音做出反应，投射到发声运动中， 通路，并在成年后发展出高度选择性的听觉 对鸟儿自己的歌声的反应。 这些特性表明，AF 在感觉学习过程中，神经元可能参与了感觉的储存， 然后，在感觉运动学习过程中， 反馈到运动路径，以指导发声的改进。 的 实验将检验这些假设。 第一，研究 在年轻的雀AF通路的神经元，在关闭的感觉 这将决定歌曲选择性出现的确切时间。 二 在学习过程中对动物发声的操纵将澄清 这些AF神经元的选择性是否由感觉经验塑造， 来自导师的反馈，来自动物自己声音的反馈，或者两者兼而有之。 在这些 实验中，鸟类发育中的发声（塑料歌曲）也将被 定量分析，并比较新兴的调谐性能， 他们的AF神经元，以增加我们对神经元如何编码的理解， 辨别这种复杂的刺激。 最后，AF提供的想法 关键的感官反馈的声乐运动通路将测试， 评估AF输入对其目标中的神经反应的贡献 在几个不同的学习阶段。

DESCRIPTION (Adapted from applicant's abstract): The long term goal is to understand the neural basis of learning and memory, particularly how the brain stores and represents complex sensory information, and how it uses sensory information to guide learning of motor behaviors. Vocal learning in songbirds provides a useful system for studying these questions. Birds learn their song from adult "tutors" in two distinct stages, both of which depend on auditory experience and feedback. First, during a critical period for sensory learning, young birds hear the tutor song, and memorize an internal representation, or "template", of this song. Then, during a sensorimotor learning period, they use auditory feedback from their own voice to gradually refine their vocal output so that it matches the stored tutor template. Moreover, birds have specialized brain structures devoted to song learning, in which many of the important neural changes are likely to occur. Finally, because song learning has a number of specific features in common with speech acquisition, it may provide particular insight into mechanisms underlying human vocal learning and critical periods for language development. The anterior forebrain (AF) pathway of the song system is known to play a critical role in song learning, but its exact function remains unclear. Neurons in this pathway respond to sounds, project to the vocal motor pathway, and by adulthood have developed highly selective auditory responsiveness to the bird's own song. These properties suggest that AF neurons might be involved during sensory learning in storage of the sensory template for song, and then, during sensorimotor learning, provide auditory feedback to the motor pathway to guide refinement of vocalizations. The proposed experiments will test these hypotheses. First, study of the neurons of the AF pathway in young finches, at the close of the sensory period, will determine exactly when song selectivity emerges. Second manipulations of the animal's vocalizations during learning will clarify whether the selectivity of these AF neurons is shaped by sensory experience of the tutor, feedback from the animal's own voice, or both. In these experiments, birds' developing vocalizations (plastic song) will also be quantitatively analyzed, and compared to the emerging tuning properties of their AF neurons, to increase our understanding of how neurons encode and discriminate such complex stimuli. Finally, the idea that the AF provides crucial sensory feedback to the vocal motor pathway will be tested by assessing the contribution of AF inputs to neural responses in its target song motor nucleus, at several different stages of learning.