Minimum norm analysis for timelock-data

[Nathan Weisz]

Dear Christine,

> I still have this problem with performing source analysis (minimum norm estimate) on timelockdata. As already mentioned, the main problem occurs in sourcegrandaverage, probably because the output data from source analysis (using cfg.method = 'mne' on timelock data) contain an avg.pow field with the dimensions 4560x211 for each subject, where 211 is the number of time samples.

i still have not fully understood your problem ... anyway ... if i recall correctly when using lcmv you get a vector of length(number_of_gridpoints) in the avg.pow field. the sample points are in avg.mom. why don't you try this:
1) add a avg.mom field with avg.mom = avg.pow
2) remove the avg.pow field (using rmfield ... or now ft_rmfield? :-))
3) then call sourcedescriptives with cfg.projectmom='yes'

otherwise run an lcmv beamformer and try sourcegrandaverage / sourcestatistics. if that works then compare your mne and lcmv source structures.

best,
nathan

> 
> I have tried several things to avoid the problem with sourcegrandaverage, but there are always new problems; for example, when I put the source data directly into sourcestatistics, without using sourcegrandaverage, there is a problem with checkdata, saying that the function requires source or volume data as input. Computing the timelockdata only for a single latency results in a problem in source analysis ('error in minimumnormestimate at 143, mom = w*dat).
> 
> Does anyone have a script for computing MNE on timelockdata that works?! I would be very glad if someone could help me out with this problem!
> 
> Thanks and Best
> Christine
> 
> 
> -- 
> Christine Grützner, geb.Tillmann
> Max-Planck-Institut für Hirnforschung
> Abt. Neurophysiologie
> Deutschordenstr. 46
> 60528 Frankfurt am Main
> Germany
> 
> Phone: +49 (0)69/6301-83225
> E-Mail: tillmann at mpih-frankfurt.mpg.de
> http://www.mpih-frankfurt.mpg.de/global/Np/Staff/tillmann.htm
> 
> 
> ----------------------------------
> 
> 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.
> 
> http://listserv.surfnet.nl/archives/fieldtrip.html
> 
> http://www.ru.nl/fcdonders/fieldtrip/
> 


----------------------------------
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/neuroimaging/fieldtrip.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20100111/3b6eef59/attachment-0002.html>