Dear Elias,
you get this error because SPM expects the same number of regressors for
each session/subject and, while you have a single condition throughout,
you have a varying number of movement/outlier regressors.
One solution could be to move your regressors of no interest in the
confound variable as we discussed earlier:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=spm;edcce0c1.1504
but it's not going to work here as the function that creates the large
fixed effect model will ignore the modification (spm_cfg_mfx).
That said, maybe that the check SPM performs is too strict as what
really matters is to check X1 and not X0:
y = X1*B1 + X0*B0 + e1
So, unless I'm mistaken, we could try to modify your FFX SPM.mat file in
order to explicitly partition your design matrix in X1 and X0. I presume
this file is quite large so could you save a subset of it:
>> load SPM.mat
>> xX = SPM.xX;
>> save xX.mat xX
and send it to me.
Best regards,
Guillaume.
On 07/05/15 13:19, Mouchlianitis, Elias wrote:
> Dear SPM experts,
>
> I want to run a mixed effects analysis for a phMRI experiment. Following
> instructions from the SPM12 manual, I have loaded all SPM.mat files for
> the FFX specification. See figure 1 how the first level design matrix
> looks. After FFX estimation I get the design matrix in figure 2. When
> taking the SPM.mat file for MFX specification I get this message:
>
> Failed 'MFX Specification'
> Error using spm_mfx (line 113)
> This is not a repeated measures design.
> In file "/cns_zfs/system/system_s9_sparc/spm/spm-12-20141016/spm_mfx.m"
> (v5859), function "spm_mfx" at line 113.
> In file
> "/cns_zfs/system/system_s9_sparc/spm/spm-12-20141016/config/spm_cfg_mfx.m"
> (v6028), function "spm_local_mfx" at line 222.
>
>
> However as you can see from the first level design, it is a repeated
> measures… not sure where I am going wrong any help would be much
> appreciated, hope I am not missing something obvious.
>
> Many thanks,
>
> Elias
>
>
--
Guillaume Flandin, PhD
Wellcome Trust Centre for Neuroimaging
University College London
12 Queen Square
London WC1N 3BG
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