I have exactly the same problem as described below. I have been using SPM5 for almost one year now and never had that problem. I just occured recently and we didn't change any of the settings.
Could it be something with the update?
Thanks a lot for your help!
"If the human brain were so simple
That we could understand it,
We would be so simple
That we couldn't."
(Emerson M. Pugh)
Dept of Neurology, Palmer 127,
Beth Israel Deaconess Medical Center / Harvard Medical School,
330 Brookline Ave, Boston, MA - 02215
Phone: (617) 632 8923
Cell: (617) 642 1191
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]On
Behalf Of John Ashburner
Sent: Tuesday, February 05, 2008 7:27 AM
To: [log in to unmask]
Subject: Re: [SPM] Change in Voxel Size
> I am doing some fMRI analysis and have noticed that after normalization and
> smoothing I have a voxel size 2x2x2 but after estimation I notice when
> viewing my spmT image that the voxel size of some of my images have changed
> to -2x2x2. Has anyone else experienced this problem? Will it cause
> problems in my data or can I combine both image types together (ie treat
> 2x2x2 and -2x2x2 as the same)? Thanks
This sounds worrying as it is the sort of thing that shouldn't happen with
correct use of SPM. How did you determine the voxel sizes? Did the flip
settings change at any point? Which version of SPM?
If you do a search through the archives for keywords "neurological and
radiological" or maybe "flip", then you should find some of the related
answers. I would suggest narrowing the search to those more recent answers
(to avoid most of the old SPM99 stuff).