NEURAL ENCODING OF DYNAMIC FEATURES OF COMPLEX SOUNDS

提案研究的长期目标是使 在理解中枢听觉系统如何编码 复杂的声音特征。 为了实现这一目标， 神经生理学和神经解剖学技术 用于表征优先编码 复杂声音的重要动态特征。 的快速变化 声音的振幅和频率将被研究，因为它们是 许多人类和动物交流的基本组成部分 声音，并在某些情况下调解音高感知和声音 本地化 本提案的具体目标是 严格研究腹侧单个细胞的反应， 耳蜗核对安静和背景中的AM和FM信号 噪声 在单细胞定位实验中，HRP将被 从记录电极喷射到细胞外以标记 记录网站的位置，并跟踪他们的连接， 中心. 单个细胞将被分成不同的群体 基于对简单声音的反应，解剖位置， 兴奋性和抑制性反应区的范围。 这些 将定性分析人群反应， 为了更好地了解耳蜗 核细胞处理它们从听觉神经接收的输入， 不同耳蜗核群的反应将是 与在实验室中获得的神经纤维的反应相比， 在相同记录、刺激和麻醉下的相同种属 条件 最后，为了最大限度地影响哺乳动物， 听觉系统，特别是人类听觉系统 在单细胞研究无法完成的情况下， 在一种有感知能力的动物身上进行 来辨别复杂的交流声音， 并且具有与人类相似的可听度曲线。 这项研究对临床科学家来说是必不可少的 开发和测试人工耳蜗和新的人工耳蜗 设计用于恢复听力的核刺激装置， 感音神经性耳聋患者。 这些发现也将 帮助语音科学家和工程师设计真实的- 时间语音解码器 因为这个项目的主要目标之一 建议是增加对职能组织的了解 的听觉系统，特别强调的途径， 处理复杂声音的特征， 特别适用于神经科医生和神经外科医生诊断 病变的功能意义、脑血管意外 以及头部外伤导致听觉功能受损

The long-term goal of the proposal research is to make significant strides in understanding how the central auditory system encodes complex sound features. To achieve this goal, state-of-the-art neurophysiological and neuroanatomic techniques will be employed to characterize pathways that preferentially encode important dynamic features of complex sounds. Rapid changes in sound amplitude and frequency will be studied since they are essential components of many human and animal communication sounds, and in some cases mediate pitch perception and sound localization. The specific aims of the present proposal are to rigorously investigate the responses of single cells in the ventral cochlear nuclear to AM and FM signals in quiet and background noise. During single-cell mapping experiments, HRP will be ejected from the recording electrode extracellularly to mark recording site locations and trace their connections with higher centers. Single cells will be grouped into different populations based on responses to simple sounds, anatomical location, and extent of excitatory and inhibitory response areas. These population responses will be analyzed qualitatively and quantitatively, and to gain a better understanding of how cochlear nucleus cells process inputs they receive from the auditory nerve, responses of different cochlear nucleus populations will be compared to responses of auditory-nerve fibers obtained in the same species under identical recording, stimulation and anesthetic conditions. Lastly, to maximize implications for the mammalian auditory system, and in particular for the human auditory system in which single-cell studies cannot be done, experiments will be performed on an animal species that has the perceptual capability of discriminating complex communication sounds such as speech, and has an audibility curve similar to that of man. The results of the proposed research will be essential for clinician scientists developing and testing cochlear implants and the newer cochlear nucleus stimulation devices that are designed to restore hearing in patients with sensorineural deafness. These findings will also be of assistance to speech scientists and engineers designing real- time speech decoders. Since one of the major goals of this proposal is to increase knowledge of the functional organization of the auditory system, with particular emphasis on pathways that process features of complex sounds, the results will be particularly useful to neurologists and neurosurgeons in diagnosing the functional significance of lesions, cerebrovascular accidents and head trauma involving compromise of auditory function.