Hi,
This probably means that you have extreme outliers in the data - possibly
because of the field-of-view issue. The best thing to check is the 4D cope
file input to high-level - load in the .gfeat/cope1 image into fslview and
look through the timepoints - hopefully this should show up where the
problem is.
Cheers.
On Sat, 8 Oct 2005, Chihiro Kuroki wrote:
> Hi all
>
> I'm running a group Feat using the latest version FSL(FSL3.2) and FSL3.1.
>
> 1. FSL3.2
> -Four sessions per one subject.
> -Single slice.
> I know FAQ #47, but it has to require the following setting.
> -add '-2D' to the flirt commands in featreqapply and feat.tcl. (Registration works fine.)
> -standard image is my own single slice high resolution image.
>
> In my higher-level analysis(Single-Group Average, One-Sample
> T-Test) on FSL3.2, I got many flame's WARNINGs.
>
> ###
> WARNING: FLAME stage 2 has given an abnormally large difference to stage 1
> x=73,y=96,z=0
> vox=319
> zts[0](vox)=5.64006
> zemlowerts[0](vox)=2.54789
> beta_mean[0](vox)=0.50859
> beta_b[0](vox)/beta_c[0](vox)=1.00022e-10
>
> WARNING: FLAME stage 2 has given an abnormally large difference to stage 1
> x=73,y=97,z=0
> vox=320
> zts[0](vox)=5.55874
> zemlowerts[0](vox)=2.5332
> beta_mean[0](vox)=0.50859
> beta_b[0](vox)/beta_c[0](vox)=1.00022e-10
>
> WARNING: FLAME stage 2 has given an abnormally large difference to stage 1
> ...
> ###
> In gsmanager.cc: line 713
> abs(zts[0](vox)-zemlowerts[0](vox))>3
> Q: These warnings is from this line... what does this line mean?
>
>
> 2. FSL3.1
> -The same data as 1 was used.
> -As written in FAQ #47, it does not require any special settings.
>
> I didn't get any flame's WARNINGs.
>
>
> I checked both zstat1.img. The distribution forms of z-score
> of the above 2 data are different from each other. (Using
> FSL3.2, it seems that the high z-score area is underestimated??)
>
> Q: Am I doing something wrong on FSL3.2?
>
> thanks,
>
--
Stephen M. Smith DPhil
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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