Using ICBM Probabilistic Atlases

[Vladimir Litvak]

Dear Will,

I haven't use these particular atlases but I've recently worked on a
similar problem. Basically you can interpolate your source data on any
MRI.  To do that you should set the source.transform field (where
'source' is beamformer output) to the transformation matrix from the
coordinate system in which you did the beamformer to the coordinate
system of the target MRI. Then you call sourceinterpolate() with that
modified source struct and the target MRI as inputs.

To get that transformation matrix you will need some fiducials and
with that I can't help you. If that atlas has a corresponding
structural image you can load that image with some software (I use
SPM) and click on some landmarks to find their coordinates. You can
then find the coordinates of the same landmarks in your beamformer
coordinate system. Of course the precision of your coregistration will
depend directly on how precisely you can define the fiducials in the
two systems. Given at least 3 matching landmarks the transformation
matrix can be computed. How it's done exactly depends on some details
that I wouldn't like to get into here.

If you don't get better help, write me and I can try to share what I know.

Best,

Vladimir




On Fri, Jun 13, 2008 at 5:20 PM, Will Findley <findley at gmail.com> wrote:
> I would like to localize activity onto the ICBM probabilistic atlases from
> LONI.  It is unclear to me how and where I should modify the DICS
> localization procedure to utilize them (particularly the tissue atlas).  I
> also do not know how to obtain fiducial positions for them.  Does anyone
> have experience localizing onto these atlases that would help?
>
> Thanks,
> Will
>
> ----------------------------------
> 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.
>
>

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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/fcdonders/fieldtrip.