Dealing with the shortcomings of spatial normalization: Multi-subject parcellation of fMRl datasets
Dealing with the shortcomings of spatial normalization: Multi-subject parcellation of fMRl datasets
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DOI:
10.1002/hbm.20210
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发表时间:
2006-08-01
影响因子:
4.8
通讯作者:
Poline, Jean-Baptiste
中科院分区:
文献类型:
--
作者:
Thirion, Bertrand;Flandin, Guillaume;Poline, Jean-Baptiste
The analysis of functional magnetic resonance imaging (fMRI) data recorded on several subjects resorts to the so-called spatial normalization in a common reference space. This normalization is usually carried out on a voxel-by-voxel basis, assuming that after coregistration of the functional images with an anatomical template image in the Talairach reference system, a correct voxel-based inference can be carried out across subjects. Shortcomings of such approaches are often dealt with by spatially smoothing the data to increase the overlap between subject-specific activated regions. This procedure, however, cannot adapt to each anatorno-functional subject configuration. We introduce a novel technique for intra-subject parcellation based on spectral clustering that delineates homogeneous and connected regions. We also propose a hierarchical method to derive group parcels that are spatially coherent across subjects and functionally homogeneous. We show that we can obtain groups (or cliques) of parcels that well summarize inter-subject activations. We also show that the spatial relaxation embedded in our procedure improves the sensitivity of random-effect analysis.