Visual and Auditory Processing Streams in the Cerebral Cortex

描述（由申请人提供）：长期以来，视觉一直是健康和疾病的模型系统，用于分析大脑皮层水平的感知和认知系统。近年来，对涉及听觉认知的高级皮质区域的理解也取得了很大进展。然而，关于听觉处理流的知识仍然远远落后于视觉。我们建议使用单单元和多单元电生理学来研究非人类灵长类动物恒河猴沿颞上回（STG）和颞下回沟（STS）的皮层区域，恒河猴的皮层组织与人类相似。我们的分析是基于这样一个假设，即在视觉和听觉系统中至少存在两种专门的处理流，一种是用于识别物体的前腹流，一种是用于分析空间的后背流。因此，我们预测，无论空间位置如何，前颞上区（AST）吻侧和初级听觉皮层（A1）外侧对听觉物体的选择性都增强（特异性目标1），而A1尾部的后颞上区（PST）对空间位置的选择性无论听觉物体类型如何都增强（特异性目标2）。我们将专注于物种特定通信呼叫的处理，并将测试颞上皮层（ST）中的神经元是否可以形成音调和呼叫者身份的不变性。在第三个特定目标中，我们将使用解剖示踪剂，注射到生理特征区域，以揭示从听觉，视觉和多感觉区域到AST和PST的输入连接。我们的研究，使用警觉的猴子进行行为任务训练，将有助于理解感知和认知在感觉系统中的统一原则。它们将进一步加深我们对中风或阿尔茨海默病导致的人类认知缺陷的理解，这些缺陷会导致视觉和听觉失认以及空间定向的丧失。这些研究也与阅读障碍和自闭症等疾病有关，这些疾病包括阅读理解或个人社交能力的问题。听觉处理缺陷是这两种疾病的共同症状，而弄清听觉皮层交流的神经机制是找到治疗方法的重要前提。最后，了解颞叶皮层与额叶皮层之间的巨大联系，将为研究高级精神疾病提供重要线索，比如精神分裂症，这种疾病通常以幻听为特征。

DESCRIPTION (provided by applicant): Vision has long served as a model system in health and disease for the analysis of perceptual and cognitive systems at the level of the cerebral cortex. Great progress has also been made in recent years regarding an understanding of higher cortical areas involved in auditory cognition. However, knowledge about auditory processing streams still lags far behind that in vision. We propose to use single-and multi-unit electrophysiology to study cortical areas along the superior temporal gyrus (STG) and sulcus (STS) in a nonhuman primate, the rhesus macaque, whose cortical organization is similar to that of humans. Our analysis is based on the hypothesis that at least 2 specialized processing streams exist both in the visual and auditory system, an antero-ventral stream for the identification of objects, and a postero-dorsal stream for the analysis of space. Thus we predict that anterior superior temporal areas (AST) rostral and lateral to primary auditory cortex (A1) show enhanced selectivity for auditory objects regardless of spatial location (Specific Aim 1), whereas posterior superior temporal areas (PST) caudal to A1 show enhanced selectivity for location in space regardless of auditory object type (Specific Aim 2). We will focus on the processing of species-specific communication calls and will test whether neurons in the superior temporal (ST) cortex can form invariances for pitch and caller identity. In a third Specific Aim, we will use anatomical tracers, injected into physiologically characterized regions, to uncover the input connections to AST and PST from auditory, visual, and multisensory areas. Our studies, using alert monkeys trained in a behavioral task, will contribute to the understanding of unified principles of perception and cognition across sensory systems. They will further our understanding of deficits in human cognition from stroke or Alzheimer's disease, which result in visual and auditory agnosia as well as loss of spatial orientation. The studies are also relevant for disorders such as dyslexia and autism, which include problems in reading comprehension or a person's ability for social communication. Auditory processing deficits are a common symptom in both, and clarification of the neural mechanisms for auditory cortical communication is a major prerequisite for finding a cure. Finally, understanding temporal cortex with its massive connections to frontal cortex will yield important clues about higher mental disorders, such as schizophrenia, which are often characterized by auditory hallucinations.