Realistic Simulations and Empirical Data: MEG Reconstructions of Time

描述（由申请人提供）：神经成像技术提供的病理综合描述需要精确的时间和空间重建。虽然血液动力学技术（功能磁共振成像和PET）通过揭示特定脑位置的病理存在与否，对健康相关研究做出了重大贡献，但病理通常首先表现为脑区域内部和脑区域之间的时间问题（例如，脑区域之间的通信减慢或功能障碍）。脑磁图（MEG）方法可以提供精确的时间信息，但该技术的物理性质复杂，该领域的进展缓慢。在美国，大约有三家主要的25 MEG系统制造商，每家都有不同的硬件（拾取线圈，传感器阵列，噪声消除方法）和软件，这使得MEG研究人员很难：1)直接比较模拟结果，测试他们不同的分析算法；2)跨地点汇集数据，以获得更多的患者数量。这个项目的目标如下。具体目标1要求生成大量模拟的视觉、体感和听觉MEG数据，使用从我们的基础/临床研究中获得的真实源配置，嵌入到真实的背景活动中，并为3种不同的商业MEG系统格式化。四种一般类型的分析技术（多偶极子、时空建模、L2最小范数、L1最小范数和波束形成方法）将应用于模拟数据。具体目标2将在已经从三个不同的MEG系统和5个受试者获得的经验数据（基本的视觉、听觉和体感协议）上测试同一套算法。这5名受试者的背景脑磁图活动将用于上述模拟。具体目标3建议完成对自由软件的修改，该软件可以读取、显示和分析来自三个MEG系统的数据，并将模拟和经验数据写入Curry（一个商业软件包）和netCDF格式，以便全国和世界各地的其他研究者可以访问这些数据和工具，直接与他们的结果进行比较。为此目的，将在MIND研究所建立和维护一个安全的协作门户。用于检查脑功能的MEG方法提供了关于大脑区域内和跨区域活动时间的无与伦比的信息。许多脑部疾病扰乱了这个时间，因此活动要么延迟，要么大脑区域不能协调一致地很好地协同工作。本项目提供了利用这一优势的各种MEG工具的综合评估。

DESCRIPTION (provided by applicant): Comprehensive descriptions of pathology afforded by neuroimaging techniques require accurate reconstructions of both time and space. While hemodynamic techniques (fMRI and PET) have made significant contributions to health-related research by revealing the presence or absence of pathology in specific brain locations, pathology often exhibits itself first as a timing problem within and between brain regions (e.g., slowing or dysfunctional communication between brain areas). Magnetoencephalographic (MEG) methods can provide precise temporal information but the physics of this technique is complex and progress in this area has been slow. There are three primary manufacturers of the ~25 MEG systems in the United States, each of which has different hardware (pickup coils, sensor arrays, noise cancellation methods) and software, making it difficult for MEG researchers to: 1) directly compare simulation results testing their different analysis algorithms and 2) pool data across sites in order to acquire larger patient numbers. The goals of this project are as follows. Specific Aim 1 requires the generation of a large set of simulated visual, somatosensory and auditory MEG data using realistic source configurations garnered from our basic/clinical studies, embedded within real background activity and formatted for the 3 different commercial MEG systems. Four general types of analysis techniques (multidipole, spatio-temporal modeling, L2 minimum- norm, L1 minimum-norm, and beamformer methods) will be applied to the simulated data. Specific Aim 2 will test the same set of algorithms on empirical data (basic visual, auditory and somatosensory protocols) already acquired from three different MEG systems and from 5 subjects. The background MEG activity from the 5 subjects will be used in the simulations noted above. Specific Aim 3 proposes to finalize modifications to free software that can read, display and analyze data from the three MEG systems and to write the simulated and empirical data into Curry (a commercial package) and netCDF formats so other investigator across the country and world may access these data and tools for direct comparison with their results. A secure collaborative portal will be set up and maintained at The MIND Institute for this purpose. MEG methods for examining brain function provide unparalleled information concerning the timing of activity within and across brain regions. Many brain pathologies disturb this timing, so that activity is either delayed or brain regions do not work well together in a concerted fashion. This project provides a comprehensive evaluation of varied MEG tools that capitalize on this strength.