source analysis attempt using DICS method

Brian Roach Brian.Roach at YALE.EDU
Fri Mar 30 18:44:38 CEST 2007

Thanks for these replies.  I have now specified

cfg.mriunits = 'mm'
cfg.sourceunits = 'mm'

Then, I should re-run sourceinterpolate.m?  That seems to produce the new
results, but the same new results whether I specify both units as 'cm' or
'mm'.  If my MRI is in 'mm' and sourceanalysis.m uses cm, which are you
supposed to use?

At 09:24 AM 3/29/2007, Robert Oostenveld wrote:
>On 29 Mar 2007, at 8:29, Jan Mathijs Schoffelen wrote:
>>a very likely cause is the incorrect specification of cfg.mriunits,
>>and cfg.sourceunits prior to calling sourceinterpolate (I did not
>>find back in the code you sent in your mail that you actually
>>called it, but I assume you did). If not specified, fieldtrip puts
>>cfg.mriunits to 'mm', and cfg.sourceunits to 'cm'. There might be a
>>discrepancy in your data there. Perhaps you even explicitly have to
>>check, whether your headmodel (in hdmfile) is defined in cm. At
>>least the dipole-grid on which sourceanalysis performs the
>>beamformer-scanning is defined in cm, and I guess the units should
>>be identical here as well.
>The standard BEM EEG volume conduction model that you might have
>copied from EEGLAB is one that is based on the MNI template brain. It
>is in MNI coordinates (linked to the AC and PC) and the units are in
>mm (corresponding with SPM standards).

More information about the fieldtrip mailing list