Receptive Field Correlates of Starling Song Recognition Behavior

描述（由申请人提供）：大脑中语音处理的关键方面之一是识别单个说话者或定义的听觉对象（如元音和辅音）的听觉特征的隔离。损害这种能力的听力损伤无法通过传统手段进行补救;特别是，在生命早期发生的听力损失导致无法发展适当的声音处理机制，并且这些机制及其发展都没有得到很好的理解。鸣禽使用发声来识别个体，许多物种可以在一生中继续学习新的联系。歌曲识别行为在欧洲椋鸟（Sturnus vulgaris）中受到了特别的关注，其社会性质使它们服从操作性条件反射范式，受试者学习区分不同个体的歌曲。最近的研究发现了一个前脑区域，即尾内侧中皮层（CMM），其中包含对训练过程中学习到的歌曲产生选择性的神经元。因此，椋鸟代表了一个有吸引力的系统，研究如何产生这种选择性，本研究的长期目标是开发严格的统计模型CMM感受野（RF）。这些模型将阐明听觉处理的神经元回路和机制，以及动物如何使用听觉信息的神经元表征来做出决策。这项建议的具体目标支持这一目标，通过研究如何两个不同的元素八哥歌曲有助于歌曲识别行为。椋鸟的歌声由一系列离散的定型元素组成，这些元素被称为主题，它们以非随机的模式演唱，单个主题由独特的光谱时间特征组合而成。该提案描述了测试序列和特征组成的相对贡献的实验，该实验假设（1）基序选择性在行为和生理水平上都产生于对特定特征的组合的敏感性，以及（2）在行为和生理水平上的基序选择性对时间背景敏感。这项研究将通过加深我们对大脑如何处理复杂感觉信息的理解，为听力损失和语言缺陷的治疗做出贡献。它开发的用于分析听觉信号的方法也可能在听觉假体设备的创建中有用。

DESCRIPTION (provided by applicant): One of the crucial aspects of vocal processing in the brain is the isolation of auditory features that identify an individual speaker or defined auditory objects like vowels and consonants. Hearing damage that compromises this ability cannot be remedied through traditional means; in particular, hearing loss that occurs early in life leads to a failure to develop the appropriate mechanisms for vocal processing, and neither those mechanisms nor their development is well understood. Songbirds use vocalizations to identify individuals, and many species can continue to learn new associations throughout life. Song recognition behavior has received particular attention in European starlings (Sturnus vulgaris), whose social nature makes them amenable to operant conditioning paradigms in which subjects learn to distinguish between songs from different individuals. Recent findings have identified a forebrain region, the caudomedial mesopallium (CMM), which contains neurons that develop selectivity for songs learned in the training procedure. Thus, starlings represent an attractive system in which to study how such selectivity arises, and the long-term objective of this research is to develop rigorous statistical models of CMM receptive fields (RFs). These models will shed light on the neuronal circuitry and mechanisms underlying auditory processing, and on how neuronal representations of auditory information are used by animals in making decisions. The specific aims of this proposal support this goal by examining how two distinct elements of starling song contribute to song recognition behavior. Starling songs comprise a series of discrete stereotyped elements called motifs that are sung in a non-random pattern, and individual motifs are composed of a unique combination of spectrotemporal features. This proposal describes experiments that test the relative contributions of sequence and feature composition under the hypotheses that (1) motif selectivity arises at both the behavioral and physiological level from sensitivity to a combination of specific features and (2) motif selectivity at the behavioral and physiological level is sensitive to temporal context. This research will contribute to treatments for hearing loss and language deficits by deepening our understanding of how the brain processes complex sensory information. The methods it develops for analyzing auditory signals may also be useful in the creation of auditory prosthetic devices.