Processing Streams in the Cerebral Cortex

描述（由申请人提供）：近年来，在理解听觉感知和认知的皮层区域方面取得了很大进展。我们的实验室以及许多其他实验室的工作已经证明，在人类和非人类动物中都存在功能专门的处理流（见Rauschecker， 2012，回顾）。腹侧的“什么”流被证明与复杂声音的识别有关；背侧的“where”流被定义为专门处理空间和运动。上一个资助期的工作集中在了解腹侧流的处理原理，并产生了许多结果（见进展报告）。下一个筹资周期的工作将集中在背流。特别是，我们建议研究醒着的恒河猴后上颞叶皮层（pST）的听觉区域以及顶叶和运动前皮层的听觉相关区域。基于先前的结果，我们预测pST和顶叶皮层的背流区域对空间位置具有特别的选择性。此外，还提出了背流功能在音频-电机控制和集成中的新扩展作用（Rauschecker, 2011）。我们将通过训练猴子在一个特殊的行为装置（“猴子钢琴”）上产生声音序列来验证这一假设。这些序列以及未经训练的控制序列将被用作功能性磁共振成像（fMRI）研究和来自同一只猴子的单/多单元记录的听觉刺激。该研究分为三个具体目标：目标1将使用功能磁共振成像和单/多单元记录研究尾状带和副带（CB/CPB）区域的时空特性调谐。空间运动的专业化将通过呈现模拟若隐若现的物体的刺激来测试。目的2和3将研究背侧流在音频-运动控制和整合中的新作用：目的2将利用功能磁共振成像与行为训练相结合；目标3将使用多个地点的并行录音

DESCRIPTION (provided by applicant): In recent years, great progress has been made in understanding cortical areas involved in auditory perception and cognition. Work from our laboratory as well as many others has demonstrated the existence of functionally specialized processing streams in both humans and nonhuman animals (see Rauschecker, 2012, for review). A ventral "what"-stream was shown to be involved in the identification of complex sounds; a dorsal "where"- stream was defined as specialized in processing space and motion. Work in the previous funding period has concentrated on understanding processing principles in the ventral stream and has produced numerous results (see Progress Report). Work in the upcoming funding cycle will focus on the dorsal stream. In particular, we propose to study auditory areas within posterior superior temporal cortex (pST) and auditory-related areas in parietal and premotor cortex of awake rhesus monkeys. Building on prior results, we predict that areas of the dorsal stream in pST and parietal cortex are particularly selective for spatial location. In addition, a new, expanded role for dorsal-stream function in audio-motor control and integration has been proposed (Rauschecker, 2011). We will test this hypothesis by training monkeys to produce sound sequences on a special-built behavioral apparatus ("monkey piano"). These sequences as well as untrained control sequences will then be used as auditory stimuli in functional magnetic resonance imaging (fMRI) studies and single-/multi- unit recordings from the same monkeys. The study is divided into three specific aims: Aim 1 will investigate tuning for spatial and temporal properties in areas of the caudal belt and parabelt (CB/CPB) using fMRI and single-/multi-unit recording. Specialization for motion-in-space will be tested by presenting stimuli mimicking looming objects. Aims 2 and 3 will study the newly proposed role of the dorsal stream in audio-motor control and integration: Aim 2 will utilize fMRI in combination with behavioral training; Aim 3 will use parallel recording from multiple sites with multi-electrode arrays (MEAs). By testing how features relevant to spatial and audio- motor functions are represented relative to each other in dorsal-stream areas, we will determine whether these functions are accomplished relatively independently in two branches of the stream, or whether they are combined into one integrated audio-spatio-motor processing pathway. Our studies, using alert monkeys trained in a behavioral task, will contribute to the understanding of unified principles of cortical function across sensory systems. They will further our understanding of deficits in human perception and 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 language comprehension or ability for social communication. Finally, understanding temporal and parietal networks with their massive connections to frontal cortex will yield important clues about higher neurological and mental dysfunctions, such as attention-deficit disorder and schizophrenia.