Visual and Auditory Processing Streams in the Cerebral Cortex

长期以来，视觉一直被用作健康和疾病的模型系统，用于分析感知和认知 大脑皮层水平的系统。近年来也取得了很大的进展， 对听觉认知所涉及的高级皮质区域的理解。然而，关于听觉的知识 处理流在视觉上仍然远远落后于这一点。我们建议使用单个和多个单元的电子设备 生理学研究非人类颞叶上回(STG)和脑沟(STS)皮质区域 灵长类，猕猴，其皮质组织与人类相似。我们的分析是基于 关于视觉和听觉中都存在至少两种特殊加工流的假设 系统，用于识别对象的前腹侧流，和用于识别对象的后背侧流 对空间的分析。因此，我们预测，前上颞区(AST)的吻侧和外侧至初级 听觉皮质(A1)对听觉对象表现出增强的选择性，而不受空间位置的影响(特定 目标1)，而A1尾侧的后上颞区(PST)显示出更强的位置选择性 在空间中，不考虑听觉对象类型(具体目标2)。我们将专注于物种的加工- 特定的通讯呼叫并将测试上颞叶(ST)皮质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，将其注射到 生理特征区域，以揭示听觉到AST和PST的输入连接， 视觉和多感官区域。我们的研究，使用经过行为任务训练的警觉猴子，将有助于 到理解跨感觉系统的感知和认知的统一原则。他们会 进一步了解中风或阿尔茨海默病导致的人类认知缺陷，这些缺陷会导致 视觉和听觉失认以及空间定向力丧失。这些研究也与精神障碍有关 如阅读困难和自闭症，包括阅读理解或一个人的能力 社交沟通。听觉处理缺陷是这两种疾病的共同症状，澄清 听觉皮质沟通的神经机制是找到治疗方法的主要前提。最后， 理解颞叶皮质及其与额叶皮质的大量联系将产生关于 高级精神障碍，如精神分裂症，通常以幻听为特征。

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 electro- physiology 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 two 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 anatomicaltracers, 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.