FMRI OF AUDITORY ATTENTION TO COMPLEX ENVIRONMENTAL SOUNDS

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。这项研究的总体目标是更好地了解人类皮层系统的组织和机制，这些系统参与引导我们注意每天复杂的环境声音的不同方面。为了实现这一目标，功能性磁共振成像（fMRI）将用于区分，映射和功能性表征参与将注意力引导到三维（3D）可定位的自然声音的大脑区域（在视力正常的人和盲人中），当参与者躺在MRI扫描仪中时，通过高保真耳机系统呈现。重点将放在（1）映射皮层路径优先处理的空间位置（“在哪里”）与识别复杂的自然声音的内容（“什么”）。我们期望在对声音的空间注意过程中激活一个特定的“额顶叶”网络，并在对同一声音刺激的内容注意过程中激活几个高级别的神经关联区域。由于我们最近发现，大脑皮层中处理动物发声（相对于手操作工具发出的声音）的部分独立通路（两种不同的声音概念类别），我们还将确定（2）沿着这些不同通路的活动沿着是否可以通过注意来调节。这将通过同时呈现声源进行评估，要求参与者忽略分散注意力的声音。我们还将能够确定额顶叶皮层网络的部分（如上所述）是否也参与“听觉流”，其中注意力被引导到处理一个声源，必须过滤掉其他声源。 志愿参与者将执行听觉行为任务，同时使用3 T GE LX研究扫描仪采集功能图像，使用回波平面和/或螺旋成像序列进行T2* 加权功能图像。我们将使用？沉默？群集采集fMRI范例（事件相关），其设计用于在扫描过程的静默期期间将高保真度声音直接传递到耳朵（耳罩下），从而最小化或消除与扫描仪噪声相关的干扰。总之，该项目中的实验旨在确定负责听觉注意的皮层系统，提供负责我们感知复杂自然声音中包含的不同类型信息的不同和重叠皮层通路的详细地图。这些结果将大大推进与人类听觉处理有关的知识体系。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overall goal of this study is to provide a better understanding of the organization and mechanism of human cortical systems involved in directing our attention to different aspects of every day, complex environmental sounds. To achieve this goal, functional magnetic resonance imaging (fMRI) will be used to differentiate, map and functionally characterize brain regions (in both sighted and blind people) involved in directing attention to three-dimensionally (3D) localizable natural sounds, presented over a high fidelity headphone system while participants are lying in the MRI scanner. Emphasis will be placed on (1) mapping cortical pathways preferential for processing the spatial location ("where") versus recognizing the content of the complex natural sounds ("what"). We expect to activate a specific "fronto-parietal" network during spatial attention to sound, and several high-level, auditory-association regions during attention to the content of that same sound stimulus. Due to our recent discovery of partially separate pathways in cortex for processing animal vocalizations relative to hand-manipulated tool sounds (two distinct conceptual categories of sound), we will also determine (2) if activity along these distinct pathways can be modulated by attention. This will be assessed by presenting simultaneous sound-sources, requiring the participant to ignore the distracting sound(s). We will additionally be able to determine if portions of the fronto-parietal cortical network (mentioned above), are also involved in "auditory streaming", wherein attention is directed to processing one sound-source, having to filter out the other(s). Volunteer participants will perform auditory behavioral tasks while functional images are acquired with a 3T GE LX research scanner, using echo-planar and/or spiral imaging sequences for T2* weighted functional images. We will use a ?silent? clustered acquisition fMRI paradigm (event-related), which is designed to allow high fidelity sound to be delivered directly to the ears (under ear muffs) during silent periods of the scanning process, thereby minimizing or eliminating interference associated with scanner noise. Together, the experiments in this project seek to identify cortical systems responsible for auditory attention, providing detailed maps of both distinct and overlapping cortical pathways responsible for our perception of different types of information contained in complex natural sounds. The results will significantly advance the body of knowledge pertaining to human auditory processing.