[FieldTrip] combining magnetometers and planad gradiometers for analysis

[Alexandre Gramfort]

Hi everyone,

> I don't know enough about the elekta-software/mne-software to know what is
> happening to the data when the ssp vectors are computed, but once we know
> enough details it should be straightforward to build it into fieldtrip.

SSP vectors are stored in fif files and applied to data only if requested.

In a typical MNE workflow, the SSP vectors are no directly applied to the raw
file (avoid data duplication on disk) but rather to the noise covariance matrix
and consequently in the whitening matrix. When computing an inverse solution,
the whitening matrix is used on the data and the lead field, hence taking
into account the SSP vectors.

Hope this helps.

-- 
Alexandre Gramfort, PhD
gramfort at nmr.mgh.harvard.edu
Dept. of Radiology MGH Martinos Center / Harvard Medical School
http://www-sop.inria.fr/members/Alexandre.Gramfort/