Hi Jesper,
Thanks for your suggestion. Adding a non-zero offset solved the
problem. SPM can estimate the model now.
Wuming
On 6/4/06, Jesper Andersson <[log in to unmask]> wrote:
> Dear Wuming,
>
> > Though there is no problem in specifying the model, however, the model
> > estimation seems no working. (The sample auditary dataset works
> > perfectly). A warning poped up and said "no inmask voxels - empty
> > analysis". I googled this message and only found several pages
> > linking to SPM source codes. Then I checked the original source code
> > (cuixuprocess.m) but cannot figure out the problem.
>
> I suspect that all you need to do is to specify a non-zero offset for
> part of your volume. SPM uses a rather Q&D masking scheme to determine
> what is brain and what is not, and if you only have a temporally
> variable signal + noise SPM will think there is no brain anywhere and
> will not complete the analysis.
>
> I suggest you set a 26x26x32 centre square to 100, add you signal to two
> voxels within that square and then add your white noise.
>
> Good luck Jesper
>
>
>
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