[FieldTrip] Source reconstruction on BEM mesh of EEG data

[Arnaud Delorme]

Dear all,

I am trying to perform source reconstruction on a BEM mesh of EEG data
The page below describes how to localize source on a BEM mesh for MEG data using minimal norm estimate on the BEM mesh itself. This is what I would like to do but for EEG data.

http://www.fieldtriptoolbox.org/tutorial/minimumnormestimate/

This page describes how to compute a leadfield matrix for EEG

http://www.fieldtriptoolbox.org/workshop/baci2017/forwardproblem/

However, the leadfield matrix created for EEG is for a 3-D grid, that can then be projected on a 3-D MRI volume - so not the projection on BEM mesh I would like. I have not been able so far to generate a leadfield matrix for a BEM surface. Now the tutorial page below in theory describes how to create one for MEG from a BEM mesh (section "Realistic single-shell model, using brain surface from segmented mri").

http://www.fieldtriptoolbox.org/example/make_leadfields_using_different_headmodels/

However, again I obtained a 3-D source model on a grid. I figured that the sourcemodel needs to look like this (the content below is for tutorial MEG file named Subject01_sourcemodel_15684.mat). However, I do not know how this file was generated and how it could be transposed for EEG (which needs 3 layers instead of 1 etc…).

sourcemodel =

  struct with fields:

                    pos: [15684×3 double]
                    tri: [31360×3 double]
                   sulc: [15684×1 double]
                   curv: [15684×1 double]
              thickness: [15684×1 double]
         brainstructure: [15684×1 double]
    brainstructurelabel: {2×1 cell}
                 inside: [15684×1 logical]

Any hint would be appreciated.
Cheers,

Arno
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20190515/c0f26588/attachment-0001.html>
-------------- next part --------------
_______________________________________________
fieldtrip mailing list
https://mailman.science.ru.nl/mailman/listinfo/fieldtrip
https://doi.org/10.1371/journal.pcbi.1002202