One thing I forgot, you need to make sure your points are expressed in
mm. I don't think it's the case in Neuromag by default.
Vladimir
On Wed, Nov 30, 2011 at 2:44 PM, Vladimir Litvak
<[log in to unmask]> wrote:
> Dear Doug,
>
> Try creating and coregistering a head model in SPM and then press 'Save' and do:
>
> D = spm_eeg_load %select your dataset
> mnipoints = spm_eeg_inv_transform_points(D.inv{1}.datareg.toMNI, headpoints)
>
> where 'headpoints' is a Nx3 matrix of your points in head coordinates.
> You can then open the MNI template image and check whether the results
> make sense.
>
> Best,
>
> Vladimir
>
> On Wed, Nov 30, 2011 at 2:25 PM, Doug Davidson <[log in to unmask]> wrote:
>> Dear Vladimir and the SPM list,
>>
>> I am trying to work out how to transform a set of source locations from our
>> Elekta software 'xfit' to the MNI coordinates in DCM for MEG/EEG.
>>
>> We have fit dipoles in a set of subjects using xfit. For each subject I have
>> the x,y, and z coordinates for each dipole in the Elekta system head
>> coordinates.
>>
>> We have also read in each subject's MEG data into SPM, created meshes from
>> the subjects' structural MRI, and co-registered the MEG data with the
>> meshes.
>>
>> I would like to fit a DCM model for the source locations corresponding to
>> each of the dipoles from xfit, in each subject. Is there a way to transform
>> the Elekta coordinates to the MNI coordinates?
>>
>> Thanks a lot for your help.
>>
>> regards,
>>
>> -Doug
>>
>> Doug Davidson
>> Basque Center for Cognition, Brain, and Language
>> Donostia, Basque Country, Spain
>>
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