Analysis of Multi-Voxel Patterns of Activity in fMRI data

描述（由申请人提供）：fMRI实验产生大量的、数值丰富的但有噪声的数据集，这对提取信号方差和建立该信号与认知变量之间的对应关系构成了挑战。 传统的分析已经通过搜索对实验操作显示出相似响应的体素簇并对这些簇内的信号进行平均来降低fMRI数据的维数。 我们引入了一种新的fMRI数据分析方法，“多体素模式分析”，该方法检查活动的更高空间频率模式-区域内反应的逐体素变化-并表明该方法大大提高了fMRI的灵敏度（Haxby等人2001; Hanson等人2004; OToole等人2004; Polyn等人2004）。 在拟议的调查中，我们将开发新的方法来分析的空间分布模式的神经活动有关的功能磁共振成像数据分析中的两个具体问题：1。 解释功能性神经解剖学中的个体间差异，以及2. 空间分布的神经群体反应与认知表征之间的关系。 这项工作将涉及由认知神经科学家、应用数学家和信号处理工程师组成的多学科团队的努力。 我们提出的分析方法的发展，调整功能神经解剖学的个人大脑的基础上，引起广泛的认知活动的神经活动的模式。 我们预测，这些方法将提高灵敏度组统计测试的功能磁共振成像数据，将允许调查的个体间的一致性较高的空间频率地形表示，并将提供明确的措施，个体间的变化的位置，组织和空间范围的功能地图，与潜在的应用研究的临床条件。 我们建议，进一步开发的方法，用于检测和分析分布式模式的神经活动，利用先验知识的结构的认知表示，与这些神经活动。 我们预测，这些方法将增加多体素模式分析的灵敏度，并将允许调查认知信息是如何在地形组织，空间分布的神经活动模式。

DESCRIPTION (provided by applicant): fMRI experiments produce large, numerically rich, but noisy data sets that pose a challenge for extracting the signal variance and establishing the correspondence between that signal and cognitive variables. Conventional analysis has reduced the dimensionality of fMRI data by searching for clusters of voxels that show similar responses to experimental manipulations and averaging the signal within those clusters. We have introduced a new approach to fMRI data analysis, "multi-voxel pattern analysis", that examines higher spatial frequency patterns of activity - the voxel-by-voxel variation of response within a region - and have shown that this method greatly increases the sensitivity of fMRI (Haxby et al. 2001; Hanson et al. 2004; OToole et al. 2004; Polyn et al. 2004). In the proposed investigations, we will develop new methods for analysis of spatially-distributed patterns of neural activity in relation to two specific problems in fMRI data analysis: 1. accounting for inter-individual variation in functional neuroanatomy, and 2. the relation between spatially-distributed neural population responses and cognitive representations. This work will involve the efforts of a multidisciplinary team consisting of cognitive neuroscientists, applied mathematicians, and signal- processing engineers. We propose the development of analytic methods for aligning the functional neuroanatomy of individual brains based on the patterns of neural activity that are elicited by a broad spectrum of cognitive activities. We predict that these methods will enhance the sensitivity of group statistical tests of fMRI data, will allow the investigation of the inter-individual consistency of higher spatial frequency topographic representations, and will provide explicit measures of inter-individual variation in the location, organization, and spatial extent of functional maps, with potential applications for studies of clinical conditions. We propose, further, to develop methods for detecting and analyzing distributed patterns of neural activity that make use of prior knowledge about the structure of the cognitive representations that are associated with those neural activities. We predict that these methods will increase the sensitivity of multi-voxel pattern analysis and will allow the investigation of how cognitive information is represented in topographically-organized, spatially-distributed patterns of neural activity.