Dorian
Are you sure your explicit mask lines up with your images? Are the
values in your mask >0?
I've checked the code and there doesn't seem to be an interaction
between the various masks, e.g., an explicit mask shouldn't raise the
threshold for implicit masking and vice versa. All the masks are
intersected to give a final mask. Still, if you have other types of
masking enabled you might try turning them off but leaving on the
explicit mask and re-running the analysis.
If you want to try to debug this, if no one else has other ideas, then
you would look at line 680 in spm_spm and check if Cm is ever
non-empty (these are the values loaded from your explicit mask). Then
line 702 in spm_spm sets Y to the in-mask data (before any stats are
done, but after all masking and thresholding).
Darren
On Mon, Oct 19, 2009 at 8:14 PM, Dorian P. <[log in to unmask]> wrote:
> Dear all,
>
> I am running a flexible factorial with an explicit mask. The
> estimations stops with error:
>
> -------------------------------
> Error running job: Error using ==> spm_spm at 861
> Please check your data: There are no significant voxels.
> ------------------------------
>
> Nevertheless, when I remove the explicit mask, the estimation runs and
> there are significant results (p < 0.001) in the areas that the mask
> covers.
>
> Why does this happen? I thought using a mask the analysis would be
> more sensible, not less.
>
> (using the last revision SPM5 r.3381)
>
> Thank you.
> Dorian
>
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