Volume conduction model for EEG DICS beamforming

Jared Van Snellenberg jaredvs at GMAIL.COM
Fri Jun 29 03:31:32 CEST 2007


Hi all,

I'm currently working on a few DICS beamforming analyses for an EEG dataset 
I have, and I have a couple of questions regarding obtaining a good volume 
conduction model to include in the cfg.vol input to sourceanalysis.

I do not have MRIs or headshape information for my subjects, but of course 
I have electrode position information in spherical coordinates (stored in 
an elec structure imported from a BESA .elp file).

It's not clear to me how to generate a volume conduction model with this 
information, so any guidance here would be greatly appreciated. Ideally, I 
would like to use a 4-shell model. The FIELDTRIP documentation indicates 
that this model is implemented, but I can not seem to find the relevant 
function (and prepare_singleshell requires headshape information or an nx3 
sensor array--I presume in grid coordinates--that I do not have). Finally, 
all of the relevant prepare_XXX functions seem to indicate that they are 
specifically for MEG data, so I wanted to make sure that whatever approach 
I use is appropriate for EEG electrodes rather than MEG sensors.

Thank you very much,

Jared Van Snellenberg
Social Cognitive Affective Neuroscience Unit
http://scan.psych.columbia.edu
(212) 854-7858 p
(212) 854-3609 f
Department of Psychology, Columbia University 
406 Schermerhorn Hall
1190 Amsterdam Avenue, Mail Code 5501
New York, NY 10027

----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/fcdonders/fieldtrip.



More information about the fieldtrip mailing list