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arXiv 2103.06347stat.MEstat.APstat.CO
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因子化二分搜索:多元高维时间序列网络结构中的变点检测

Factorized Binary Search: change point detection in the network structure of multivariate high-dimensional time series

Martin Ondrus, Emily Olds, Ivor Cribben

AI总结:

提出 FaBiSearch 方法,结合非负矩阵分解与新型二分搜索检测高维时间序列网络变点,并在静息态和阅读任务 fMRI 数据中验证其动态脑网络分析能力。

摘要:

功能磁共振成像(fMRI)时间序列数据为理解脑连接的时间行为提供了独特机会,而能够揭示该器官复杂动态运作机制的模型在神经科学中备受关注。我们的动机是为高维全脑 fMRI 数据开发准确的变点检测和网络估计技术。为此,我们提出因子化二分搜索(factorized binary search,FaBiSearch),这是一种用于多元高维时间序列网络结构的新型变点检测方法,旨在理解大脑的大规模特征与动态。FaBiSearch 采用非负矩阵分解这一无监督降维技术,并使用一种新的二分搜索算法来识别多个变点。此外,我们还提出了一种用于估计变点之间数据网络的新方法。我们试图理解大脑的动态机制,尤其是针对两个 fMRI 数据集。第一个是静息态 fMRI 实验,受试者在三次访视中接受扫描。第二个是基于任务的 fMRI 实验,受试者阅读《哈利·波特与魔法石》第9章。对于静息态数据集,我们考察动态功能连接的重测行为;而对于基于任务的数据集,我们探索阅读过程中的网络动态,以及不同受试者之间的变点是否与故事中的关键情节转折相吻合。此外,我们识别脑网络中的枢纽节点并考察其动态行为。最后,我们将讨论的所有方法在 CRAN 上的 R 包 fabisearch 中提供。

英文摘要:

Functional magnetic resonance imaging (fMRI) time series data presents a unique opportunity to understand the behavior of temporal brain connectivity, and models that uncover the complex dynamic workings of this organ are of keen interest in neuroscience. We are motivated to develop accurate change point detection and network estimation techniques for high-dimensional whole-brain fMRI data. To this end, we introduce factorized binary search (FaBiSearch), a novel change point detection method in the network structure of multivariate high-dimensional time series in order to understand the large-scale characterizations and dynamics of the brain. FaBiSearch employs non-negative matrix factorization, an unsupervised dimension reduction technique, and a new binary search algorithm to identify multiple change points. In addition, we propose a new method for network estimation for data between change points. We seek to understand the dynamic mechanism of the brain, particularly for two fMRI data sets. The first is a resting-state fMRI experiment, where subjects are scanned over three visits. The second is a task-based fMRI experiment, where subjects read Chapter 9 of Harry Potter and the Sorcerer's Stone. For the resting-state data set, we examine the test-retest behavior of dynamic functional connectivity, while for the task-based data set, we explore network dynamics during the reading and whether change points across subjects coincide with key plot twists in the story. Further, we identify hub nodes in the brain network and examine their dynamic behavior. Finally, we make all the methods discussed available in the R package fabisearch on CRAN.

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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