source analysis attempt using DICS method

Robert Oostenveld r.oostenveld at FCDONDERS.RU.NL
Thu Mar 29 15:24:57 CEST 2007


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).

Robert


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