single trial source signal

[Jan-Mathijs Schoffelen]

Vasan,

I feel that FieldTrip has the capability of extracting the single  
trial source signals. I think that MNE and LORETA do not fully support  
it yet, but in order to get there, you may have to hack the code a  
bit. With LCMV it is certainly possible. The only thing you have to do  
is specify cfg.keepfilter = 'yes' prior to sourceanalysis. The output  
to sourceanalysis will contain a field source.avg.filter, which  
contain per voxel the beamformer weights.
You can get the single trial source data per voxel by doing something  
like this on the command line:

singletrialvoxeldataofvoxelXintrialY = source.avg.filter{X} *  
data.trial{Y}. Et voilà.

MNE and LORETA provide the projection matrix in one big shot, and as  
far as I know do not yet output the filt-matrix directly, but it  
should be possible to extract these from the functions and apply the  
same logic.

Good luck,

Jan-Mathijs

On 30 Nov 2009, at 21:02, Sreenivasan Rajamoni Nadar wrote:

> Dear FieldTrip users,
>
> I personally feel that the FieldTrip (latest version) does not seems  
> to having the capability to extract single trial source signals  
> using any of the the time domain beamformers: LCMV, MNE, SAM,  
> LORETA, RV  or using the frequency domain beamformer methods like  
> DICS and PCC !!
>
> Please let me know if any of you made plugin codes to Fieldtrip to  
> get single trial source data? Robert, Could you let me know if there  
> is any other version which does the above?
>
> Thank you,
> Vasan
>
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> ----------------------------------
>
> 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/
>

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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.