Title
Improving permutation test power for group analysis of spatially filtered MEG data.
Abstract
Non-parametric statistical methods, such as permutation, are flexible tools to analyze data when the population distribution is not known. With minimal assumptions and better statistical power compared to the parametric tests, permutation tests have recently been applied to the spatially filtered magnetoencephalography (MEG) data for group analysis. To perform permutation tests on neuroimaging data, an empirical maximal null distribution has to be found, which is free from any activated voxels, to determine the threshold to classify the voxels as active at a given probability level. An iterative procedure is used to determine the distribution by computing the null distribution, which is recomputed when a possible activated voxel is found within the current distributions. Besides the high computational costs associated with this approach, there is no guarantee that all activated voxels are excluded when constructing the maximal null distribution, which may reduce the statistical power. In this study, we propose a novel way to construct the maximal null distribution from the data of the resting period. The approach is tested on the MEG data from a somatosensory experiment, and demonstrated that the approach could improve the power of the permutation test while reducing the computational cost at the same time.
Year
DOI
Venue
2004
10.1016/j.neuroimage.2004.07.007
NeuroImage
Keywords
DocType
Volume
Magnetoencephalography,Permutation test
Journal
23
Issue
ISSN
Citations 
3
1053-8119
9
PageRank 
References 
Authors
1.77
7
5
Name
Order
Citations
PageRank
Wilkin Chau110017.41
Anthony R McIntosh241758.37
Stephen E Robinson391.77
Matthias Schulz4177.18
Christo Pantev59013.71