[FieldTrip] Quality of beamforming on MNI template vs single-subject MRI

[Andrea Brovelli]

  Dear all,

I used DICS and compared the quality of the beamforming using two 
different source spaces (3D grids):

1) MNI template space as described in 
http://fieldtrip.fcdonders.nl/example/create_single-subject_grids_in_individual_head_space_that_are_all_aligned_in_mni_space

2) Single subject 3D grid using anatomical MRI

The number of sources in the two models is similar (approx. 3500 
sources). However, the results using the MNI template are less 
significant. That is, the statistical analysis testing a significant 
increase in power post-stimulus with respect to baseline give higher 
p-values (in some region of interest).

Questions:

Does anyone know why ?

Is the use of the MNI template the only (and best) way to allow 
statistical analysis across subjects in the source space ?

thanks a lot

Andrea



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