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arXiv 1102.1101cs.CVq-bio.NC
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fMRI-based行为预测的全变差正则化

Total variation regularization for fMRI-based prediction of behaviour

INRIA(法国国家信息与自动化研究所);CEA(法国原子能和替代能源委员会);INSERM(法国国家健康与医学研究院)

Vincent Michel, Alexandre Gramfort, Gaël Varoquaux, Evelyn Eger, Bertrand Thirion

摘要:

虽然医学成像通常提供大量数据,但提取用于预测诊断的相关信息仍然是一个困难的挑战。功能磁共振成像(fMRI)数据,提供了一个间接的测量任务相关的或自发的神经元活动,经典的分析质量单变量程序产生的统计参数图。这种分析框架忽视了大脑组织的一些重要原则:群体编码,分布和重叠表示。多变量模式分析,即,从大脑激活模式预测行为变量更好地捕捉了这种结构。为了处理高维数据,学习方法必须正则化。然而,在标准的正则化方法中没有考虑图像的空间结构,因此提取的特征通常难以解释。利用图像梯度的l_1范数,也称为l_1范数,可以获得更多信息和可解释的结果。它的总变差(TV),作为正则化。我们首次将这种方法应用于功能磁共振成像数据,并表明TV正则化非常适合大脑映射的目的,同时也是大脑解码的强大工具。此外,本文提出了第一次使用TV正则化分类。

英文摘要:

While medical imaging typically provides massive amounts of data, the extraction of relevant information for predictive diagnosis remains a difficult challenge. Functional MRI (fMRI) data, that provide an indirect measure of task-related or spontaneous neuronal activity, are classically analyzed in a mass-univariate procedure yielding statistical parametric maps. This analysis framework disregards some important principles of brain organization: population coding, distributed and overlapping representations. Multivariate pattern analysis, i.e., the prediction of behavioural variables from brain activation patterns better captures this structure. To cope with the high dimensionality of the data, the learning method has to be regularized. However, the spatial structure of the image is not taken into account in standard regularization methods, so that the extracted features are often hard to interpret. More informative and interpretable results can be obtained with the l_1 norm of the image gradient, a.k.a. its Total Variation (TV), as regularization. We apply for the first time this method to fMRI data, and show that TV regularization is well suited to the purpose of brain mapping while being a powerful tool for brain decoding. Moreover, this article presents the first use of TV regularization for classification.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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