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example:create_single-subject_grids_in_individual_head_space_that_are_all_aligned_in_brain_atlas_based_mni_space [2017/04/20 13:06]
robert cleaned up the matlab code, copied it over to a test script
example:create_single-subject_grids_in_individual_head_space_that_are_all_aligned_in_brain_atlas_based_mni_space [2017/08/17 11:21] (current)
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 ===== Create brain atlas based MNI-aligned grids in individual head-space ===== ===== Create brain atlas based MNI-aligned grids in individual head-space =====
  
-When combining the source-level data of multiple subjects this data is typically first interpolated (e.g. using **[[reference:​ft_sourceinterpolate]]**) and then spatially normalized to a template brain (e.g. using **[[reference:​ft_volumenormalise]]**). However it is also possible to define the source-reconstruction grid for each individual subject in such a way that all these grids are already aligned in MNI-space. The combination or statistic of source-level data across subjects can then directly be computed within the source-structure without the need to interpolate and normalize each volume. In addition, the position of the grid points can be chosen in a way that only locations corresponding to particular brain areas (parcels) are included. The procedure is as follows. First, a template grid is computed on the basis of the standard head model located in the FieldTrip template directory. Subsequently,​ a brain atlas is loaded using  **[[reference:​ft_read_atlas]]**. On the basis on the brain atlas and the template grid it is possible to create a binary mask of all locations in the template grid that match atlas locations using **[[reference:​ft_volumelookup]]**. Finally the mask is used to determine which location shall be defined as '​inside'​ the head model. ​+When combining the source-level data of multiple subjects this data is typically first interpolated (e.g. using **[[reference:​ft_sourceinterpolate]]**) and then spatially normalized to a template brain (e.g. using **[[reference:​ft_volumenormalise]]**). However it is also possible to define the source-reconstruction grid for each individual subject in such a way that all these grids are already aligned in MNI-space. The combination or statistic of source-level data across subjects can then directly be computed within the source-structure without the need to interpolate and normalize each volume. In addition, the position of the grid points can be chosen in a way that only locations corresponding to particular brain areas (parcels) are included. ​ 
 + 
 +The procedure is as follows. First, a template grid is computed on the basis of the standard head model located in the FieldTrip template directory. Subsequently,​ a brain atlas is loaded using  **[[reference:​ft_read_atlas]]**. On the basis on the brain atlas and the template grid it is possible to create a binary mask of all locations in the template grid that match atlas locations using **[[reference:​ft_volumelookup]]**. Finally the mask is used to determine which location shall be defined as '​inside'​ the head model. ​
  
 <code matlab> <code matlab>