Dear Jeremy,

On Thu, Apr 15, 2010 at 8:51 PM, Jeremy Nelson <[log in to unmask]> wrote:
> Hi Vladimir,
>
> I have several SPM DCM for EEG questions I was hoping you could help me with:
>
> First, I am trying to run the DCM_ERP_example.m script using the MMN
> data via the website (mafdeMspm8_subject1.dat/mat).  However, I keep
> getting this error:
>
>>> DCM_ERP_example
> determining skin compartment (1)
> determining source compartment (3)
> projecting electrodes on skin surface
> combining electrode transfer and system matrix
> determining skin compartment (1)
> determining source compartment (3)
> projecting electrodes on skin surface
> combining electrode transfer and system matrix
> ??? Error using ==> prepare_vol_sens at 261
> unsupported volume conductor model for EEG
>
> Error in ==> forwinv_prepare_vol_sens at 11
> [varargout{1:nargout}] = funhandle(varargin{:});
>
> Error in ==> spm_dcm_erp_dipfit at 136
>    [DCM.M.dipfit.vol, DCM.M.dipfit.sens] =
>    forwinv_prepare_vol_sens(D.inv{D.val}.forward.vol, ...
>
> Error in ==> spm_dcm_erp at 53
> DCM    = spm_dcm_erp_dipfit(DCM);
>
> Error in ==> DCM_ERP_example at 93
> DCM      = spm_dcm_erp(DCM);
>
> I am running MATLAB 7.7.0 (R2008b) on Windows XP with SPM8b and the
> r3684 update.
>

I'm not familiar with this error, but it might have something to do
with version clashes. Could you just download SPM8 again from the
website (the version you get is already up-to-date you don't need the
updates), make sure you have the default path with just the main SPM
folder added to it and if you still get the problem, let me know?

> On a related note, I have not had success getting SPM to read my
> Neuroscan .AVG files - but that's not a huge deal, as I needed to
> stack and transpose my matrices into a single file, so I converted
> them all to .DAT.  However, when I did this I had to strip the header
> data from the .DAT files so MATLAB would read them.  Now I currently
> have a single .DAT file for each subject that is 64 (electrode sites)
> X 6001 (timepoints) X 3 (experiment conditions).  My questions are: is
> this the appropriate matrix type I need for DCM? And, what metadata do
> I need for each file to load it directly into DCM (by-passing all the
> SPM preprocessing)?  I was hoping to get this from the DCM_ERP_example
> (using mafdeMspm8_subject1.dat/mat as guides), but since those files
> do not seem to be working, I am hesitant to do so.

This is a little complicated way to do things and I'm afraid you'll
have to do a little programming to make it work. You can use the
attached example script and replace the random data there with your
data. If you can't make it work we'll help you when you come to the
course.

>
> And, lastly, are there known issues with SPM and MATLAB 7.10.0
> (R2010a)?  I am running that on my laptop and have some strange
> errors/processing halting messages that I do not have when I run
> SPM/MATLAB 7.7.0 on my desktop.
>

I don't know as I use an older version but my colleague Guillaume
Flandin ([log in to unmask]) is responsible for compatibility
among other things and I'm sure he'll be interested to get the details
from you and will provide you some advice.

>
> PS - What level are the SPM workshops taught at?  As a newcomer to
> MATLAB (and programming in general), would they be approachable for
> someone like me?

We hope to be able to accommodate people with different backgrounds.
The theoretical talks do not rely on any programming knowledge and the
demos show how to do things with the GUI. During the practical day the
students will work individually so you can choose to do things that
match your level of expertise.

With that, the more you can read and try things out before you come to
the course, the more you'll benefit from it because usually it takes
many iterations for everything to sink in and it'd be better if when
you come to the course things are not completely unfamiliar.

Best,

Vladimir