| 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).
Do you mean 5 volumes per scan, or 5 planes per scan? When you have a
limited field of view, then it may be the case that the spatially
normalised images from A do not share any common voxels with normalised
images from B. You can check this with the <Check Reg> button. If
this is the case, then it should explain the error.
|
| 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.
I think the grey matter masking is hidden within some forms of analysis,
in which the thresholds are assigned some sensible default value.
| 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.
Although no SPM.mat file is written, I think the analysis should have
written the various images, including the mask.img.
Best of luck,
-John
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