NEURAL PROCESSING OF BINAURAL INFORMATION

这项研究计划将评估双耳的程度 信息是分层处理和表示的 沿着听神经轴的位置。脑功能的神经加工 双耳信息从上级汇聚开始 两只耳朵突起的橄榄复合体(SOC)， 人们普遍认为，在这个层面上的双耳互动 建立一个代码，该代码基本上原封不动地沿着 通向大脑皮层的上行听觉通路。然而，分歧 单声道和双声道在SOC和 从而为潜在的后处理提供结构衬底 双耳信息。这项研究计划将确定 双耳这些更高层次的相互作用的贡献 通过比较SOC的响应进行信息处理，次等 丘脑(IC)和初级听觉皮质(AI)对操作的影响 平均双耳水平和耳间强度差异和 时间到了。单个神经元在这三个水平上的反应 长爪沙鼠的初级听觉通路 将通过细胞外记录和二分法进行评估 显示已校准的音调和噪音。初步数据 指出双耳反应中的几个重要差异 SoC和IC-本计划将决定 这些差异代表了新出现的层级过程。这 对双耳处理的详细评估不仅将说明 在上行路径中出现新的编码方案， 但也将允许更详细地检查 双耳反应的地形组织。例如，这一点 程序将确定人工智能中的总双耳频段 根据对以下各项的敏感度掩蔽更具体的组织 两耳间的强度差异和平均双耳水平。 最终，这种双耳处理的检查在多个 听觉系统的水平将产生突触的模型 塑造双耳反应的机制。在……的最后阶段 在这个五年计划中，这些机制将被探索 直接通过细胞内记录。从以下方面获得的知识 这项研究将扩大我们对规则的理解 双耳信息处理，因此，我们对 单侧和双侧听力损害的后果。

This research program will evaluate the extent to which binaural information is processed hierarchically and represented topographically along the auditory neuraxis. Neural processing of binaural information begins with convergence at the superior olivary complex (SOC) of projections arising from the two ears, and it is commonly held that binaural interactions at this level establish a code that is relayed essentially unaltered along the ascending auditory pathway to the cortex. However, divergent monaural and binaural pathways converge at sites beyond SOC and thus provide structural substrates for the potential reprocessing of binaural information. This research program will ascertain the contribution of these higher level interactions of binaural information processing by comparing responses at SOC, inferior colliculus (IC) and primary auditory cortex (AI) to manipulation of average binaural level and interaural disparities in intensity and time. The responses of single neurons at these three levels of the primary auditory pathway in the gerbil (Meriones unguiculatus) will be assessed by extracellular recording and dichotic presentation of calibrated tones and noise. Preliminary data indicate several important differences in binaural responses at SOC and IC --- this program will determine the extent to which these differences represent emergent hierarchical processes. This detailed assessment of binaural processing will not only illuminate the emergence of new coding schemes in the ascending pathway, but will also permit examination in greater detail of the topographic organization of binaural responses. For example, this program will determine whether the gross binaural bands in AI mask a more specific organization based on sensitivities to interaural intensity differences and average binaural level. Ultimately, this examination of binaural processing at multiple levels of the auditory system will generate models of the synaptic mechanisms that shape binaural responses. In the final phase of this five year program, these mechanisms will be explored directly by intracellular recording. The knowledge gained from this research will extend our understanding of the principles of binaural information processing and, hence, our appreciation of the consequences of unilateral and bilateral hearing impairment.