Dear experts,

I am running an analysis using quite a few ROIs, and when I run the analysis, I get error messages saying

"warning: no valid data in ROI ..."

I was wondering how 'bad' that is, and what happens with the data:

- Does it mean there are no valid voxels for the whole mask (or could it be just a couple of voxels missing)
- is it a sign of bad normalisation (both the subjects and the masks are in MNI space)
- does the program then use 'emptiness' for analysis, or does it ignore the data from the subjects it has no data for?
- if the program ignores some of the data, is that only the data from the "problematic masks" or the whole subject?

Many questions, I know, but I would be grateful for any information/advice on this.

Thank you very much in advance!
Elise