problem using read_fcdc_event function

P.vandenHurk P.vandenHurk at CS.RU.NL
Thu Mar 8 09:51:36 CET 2007


Hello,

Is it possible to work with .bdf files in the fieldtrip environment? I
am asking because I have this problem with the read_fcdc_event function
(by the way I don't have any problems when I use the read_fcdc_header
function)?

Thanks for your comment,

Kind regards,
Paul

Nathan Weisz schreef:
> hi robert,
>
> thanks for your quick help.
>
>> Given that you do not report explicit errors, I suspect problems with
>> different coordinates
>
> indeed i overlooked to explicitely state the source and mri-units in
> sourceinterpolate.
>
> the nai-image looks better now, although perhaps a little deep (also
> sme yellow in the middle; perhaps as a result of correlated bilateral
> activity?). but it's not the mri of the individual and i still have
> find out more about the usage and the options of sourceanalysis.
>
>> I don't know whether the small number of electrodes would be a
>> problem for beaming  the data.
>
> don't know too ... but van Veen et al. used even less in their 1997
> paper.
>
>> Are the dipoles (grid.pos) in mm? It should be in mm, just as your
>> head model. Note that beamforming is much more sensitive to head
>> model misspecification than plain dipolefitting, so you may want to
>> use a (standard) BEM model instead of a spherical model.
>
> i found a standard bem in the dipfit plugin folder of eeglab
> (standard_vol.mat).
>
> >> vol
>
> vol =
>
>      bnd: [1x3 struct]
>     cond: [0.3300 0.0041 0.3300]
>      mat: [3000x3000 double]
>     type: 'dipoli'
>
> i guess that i can simply exchange my standard spherical model (same
> as in eeglab) and use this bem volume for calculating the leadfield.
> one aspect are the electrode locations: the positions are given on a
> sphere ... so probably there'll has to be some transformation of the
> positions.
>
>> please use sourceplot with cfg.method='slice' instead (sliceinterp is
>> deprecated).
>
> still used sliceinterp this time ... found it a little more easy to use.
>
> all the best,
> nathan
>
>
>
> ------------------------------------------------------------------------
>

--

-----------------------------------------------------------
Paul van den Hurk

Joint Principal Investigator

Mindfulness Project

Inserm U280, Lyon, France,

Radboud University Nijmegen:
Department of computer sciences and
Department of Medical Physics and Biophysics/126
Geert Grooteplein 21 6525 EZ Nijmegen

Email: P.vandenHurk at cs.ru.nl

Tel: 024-3613326



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