Dear Jason,
> I am getting the following error when I try a design with one
> covariate, two nuisance variables and eleven subjects:
>
> Any insight is greatly appreciated
> >>
> SPM99: spm_spm_ui (v2.33) 16:44:33 - 17/07/2000
>
> ========================================================================
>
> Mapping files : ...done
>
> Calculating globals : ...done
>
> Design configuration : ...done
>
> Saving SPMstats configuration : ...SPMcfg.mat saved
>
> Design reporting : ...done
>
> Completed : 16:47:12 - 17/07/2000
>
> SPM99: spm_spm (v2.37) 16:47:20 - 17/07/2000
>
> ========================================================================
>
> Initialising design space : ...done
>
> Output images : ...initialised
>
> Plane 68/68 , plank 1/1 : ...done
>
> Warning: No inmask voxels - empty analysis!
There might be several reasons for this. SPM99 applies some
masks/thresholding to each voxel time-series prior to the analysis. (For
details about these, please take a look at
http://www.mailbase.ac.uk/lists/spm/2000-06/0196.html)
One possible explanation for an empty analysis is that one or more of
your images consist only of zero voxels. To check this, go to your
analysis directory and type in matlab:
load SPM
a = cat(2, VY.pinfo);
any(isnan(a(1,:)))
If this returns 1, this means that there is at least one scan, which has
got only zero voxels. (spm_global would return NaN in such a case). To
get then the corresponding image names:
VY(isnan(a(1,:))).fname
The next thing to check is to look at the stereotactic normalization of
each subject, whether every brain volume is (roughly) at the same
position.
Furthermore, you could check, whether the single subject analyses would
run through fine.
If all this is not the case of your trouble, please specify your chosen
global options and of which modality the data is (I assume PET?).
Hope this helps, Stefan
--
Stefan Kiebel
Functional Imaging Laboratory
Wellcome Dept. of Cognitive Neurology
12 Queen Square
WC1N 3BG London, UK
Tel.: +44-(0)20-7833-7478
FAX : -7813-1420
email: [log in to unmask]
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