source analysis attempt using DICS method

Brian Roach Brian.Roach at YALE.EDU
Mon Apr 2 20:06:47 CEST 2007


After re-running the sourceanalysis and sourceinterpolate, I seem to get a
better looking plot using cfg.funparameter = 'pow', but when I use
cfg.funparameter = 'nai', I get this error message:

 >> sliceinterp(cfg, sourceInterp)
??? Error using ==> sliceinterp at 175
no functional data supplied

I did not get this before, and the only thing that I have changed is the
specification of the units, as listed below in the previous e-mail.  Has
anyone else seen this error or have ideas about a fix?

thanks,
Brian

At 12:44 PM 3/30/2007, you wrote:
>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?
>
>
>thanks,
>Brian
>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).
>>
>>Robert
>



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