Spatiotemporal localization of significant activation in MEG using permutation tests.
Spatiotemporal localization of significant activation in MEG using permutation tests.
复制标题
使用排列测试对 MEG 中显着激活的时空定位。
DOI：
10.1007/978-3-540-45087-0_43
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Leahy,RichardM
中科院分区：
文献类型：
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作者：
Pantazis,Dimitrios;Nichols,ThomasE;Baillet,Sylvain;Leahy,RichardM
我们描述了使用非参数排列测试来检测激活皮质限制地图的电流密度从脑磁图数据计算。该方法适用于将事件相关MEG映射到共配准的皮质表面的任何逆成像方法。为了确定应用于从这些地图计算的统计数据的适当阈值，重要的是控制与测试成千上万个假设（每个表面元素一个）相关联的多个测试问题。通过随机排列前和后刺激数据从收集的个别时期的事件相关的研究，我们开发的阈值，控制familywise（1型）的错误率。这些阈值是基于最大强度的分布，这隐含地说明了皮层地图中的空间和时间相关性。我们证明了该方法在应用程序中的模拟数据和实验数据的体感诱发反应的研究。
We describe the use of non-parametric permutation tests to detect activation in cortically-constrained maps of current density computed from MEG data. The methods are applicable to any inverse imaging method that maps event-related MEG to a coregistered cortical surface. To determine an appropriate threshold to apply to statistics computed from these maps, it is important to control for the multiple testing problem associated with testing 10’s of thousands of hypotheses (one per surface element). By randomly permuting pre- and post-stimulus data from the collection of individual epochs in an event related study, we develop thresholds that control the familywise (type 1) error rate. These thresholds are based on the distribution of the maximum intensity, which implicitly accounts for spatial and temporal correlation in the cortical maps. We demonstrate the method in application to simulated data and experimental data from a somatosensory evoked response study.