Visual and Auditory Processing Streams in the Cerebral Cortex

描述（由申请人提供）：视觉长期以来一直作为健康和疾病中的模型系统，用于分析大脑皮层水平的感知和认知系统。近年来，关于听觉认知的高级皮层区域的理解也取得了很大进展。然而，有关听觉处理流的知识仍然远远落后于视觉。我们建议使用单和多单位的电生理学研究皮层区域沿着的上级颞回（STG）和沟（STS）在非人灵长类动物，恒河猴，其皮质组织是类似的人类。我们的分析是基于这样的假设，即至少有2个专门的处理流存在于视觉和听觉系统，一个前腹流的对象识别，和一个后背流的空间分析。因此，我们预测，前上级颞区（AST）吻侧和外侧的初级听觉皮层（A1）表现出增强的选择性听觉对象，无论空间位置（具体目标1），而后上级颞区（PST）尾部的A1表现出增强的选择性空间位置，无论听觉对象的类型（具体目标2）。我们将专注于特定物种的通信呼叫的处理，并将测试是否在上级颞（ST）皮层的神经元可以形成音高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，注入生理特征区域，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，使用在行为任务中训练的警觉猴子，将有助于理解跨感觉系统的感知和认知的统一原则。他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，这些缺陷导致视觉和听觉失认症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一个人的社交能力问题。听觉处理缺陷是两者的共同症状，并且澄清听觉皮层通信的神经机制是找到治疗方法的主要先决条件。最后，了解颞叶皮层及其与额叶皮层的大量联系将为更高级的精神障碍提供重要线索，例如精神分裂症，其特征通常是幻听。

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.