Dear Kris,
as i understand your question, you have 5 slices per subjects. Can it be,
that their is
no overlap of these slices, when you do the gruop analysis?
Are the images correctly normalized ? One way to prove this, is to make
an mean-image across all subjetcs and look, how good the normalisation and
overlap of the subjects are.
Karsten
Kris Boksman wrote:
> Hello,
>
> We are still having problems with the "NO inmask voxels - empty analysis"
> message when we do any group analysis with two particular subjects (A and
> B). The individual analysis (i.e. for A and for B) look fine, and we can
> do analyses with A or B and other subjects (i.e. {A, C, D, E} or {B, C,
> D}, etc) but when we do any analyses with A and B together (with or
> without any additional subjects) we get the above error message.
>
> We are using fMRI, and the error occurs when estimating a specified model.
> There are at most 5 subjects (as few as 2) with 63 scans each, 5 volumes
> per scan (not a lot).
>
> We are not using grey matter thresholding (to my knowledge, anyway), and
> when looking at the mask.img for the individual subjects, the correct
> voxels appear to be included. For the group analyses when we get the
> error message, no results files are output, so I can't examine the
> mask.img files to see what voxels survive the filtering.
>
> I'm afraid I have little intuition as to what may be happening - I'm
> confused as to why this would happen only when subjects A and B are
> included in a group.
>
> THanks for any help or suggestions you can offer,
>
> Kristine
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Kristine Boksman, B.Math The University of Western Ontario
> M.A.2 Clinical Psychology Department of Psychology
> [log in to unmask] Office: Rm 7250a
>
> There are two ways to live your life.
> One is as though nothing is a miracle.
> The other is as though everything is a miracle.
> Albert Einstein (1879-1955)
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
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Dipl. phys. Karsten Specht
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