Dear all
Rik remember correctly, I have been writing about effects of interest
a few times. I think one of the better ones was:
http://www.jiscmail.ac.uk/cgi-bin/wa.exe?A2=ind05&L=SPM&P=R101943&m=19070
but also have a look at:
http://www.jiscmail.ac.uk/cgi-bin/wa.exe?A2=ind05&L=SPM&P=R104595&m=19070
The relevant place in spm_spm is around line 466::
%-If xVi.V is not defined compute Hsqr and F-threshold under i.i.d.
%--------------------------------------------------------------------------
if ~isfield(xVi,'V')
Fcname = 'effects of interest';
iX0 = [SPM.xX.iB SPM.xX.iG];
xCon = spm_FcUtil('Set',Fcname,'F','iX0',iX0,xX.xKXs);
X1o = spm_FcUtil('X1o', xCon(1),xX.xKXs);
Hsqr = spm_FcUtil('Hsqr',xCon(1),xX.xKXs);
trRV = spm_SpUtil('trRV',xX.xKXs);
trMV = spm_SpUtil('trMV',X1o);
% Threshold for voxels entering non-sphericity esimtates
%----------------------------------------------------------------------
try
UFp = eval(['defaults.stats.' lower(defaults.modality)
'.ufp']);
catch
UFp = 0.001;
end
UF = spm_invFcdf(1 - UFp,[trMV,trRV]);
end
Hope this helps
Torben
Torben Ellegaard Lund
Assistant Professor, PhD
The Danish National Research Foundation's Center of Functionally
Integrative Neuroscience (CFIN)
Aarhus University
Aarhus University Hospital
Building 30
Noerrebrogade
8000 Aarhus C
Denmark
Phone: +4589494380
Fax: +4589494400
http://www.cfin.au.dk
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Den 02/10/2008 kl. 13.21 skrev Rik Henson:
> It removes the user-specified "nuisance" regressors (eg movement
> parameters) from estimation of the temporal autocorrelation
> (nonsphericity). I think this was discussed in the emaillist by
> Torben Lund a while ago (but which I admit I cannot find now, so am
> probably misremembering). I haven't explored whether it actually
> makes much difference in practice.
>
> Rik
>
>> Dear Dr. Henson, Dear SPM experts
>>
>> as I wrote yesterday, Volkmar Glauches answer on the mailing list
>> resolved my problem that I had with your script.
>>
>> Nevertheless I have a last question regarding one section in your
>> script that is not clear to me:
>> What does the script in the "Update real/nuisance in design matrix
>> (for nonsphericity corection)" section.
>> Is this a usual step that is automatically included in SPM5
>> analyses when you do them without batching. Or is this a special
>> feature that you added for yor purposes.
>> In other words In a 'simple' first level event-related analyses
>> with 6 movement parameters/session, is this step necessary?
>>
>> Thank you very much for your help!
>>
>> Best regards
>>
>> Bernhard Haslinger
>>
>
>
> --
>
> -------------------------------------------------------
>
> DR RICHARD HENSON
> MRC Cognition & Brain Sciences Unit
> 15 Chaucer Road
> Cambridge, CB2 7EF
> England
> EMAIL: [log in to unmask]
> URL: http://www.mrc-cbu.cam.ac.uk/people/rik.henson/personal
>
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