Hi,
The mean displacement should go to zero at the reference point. Are you running this via the FEAT GUI or separately? Does the mean displacement go to zero at some other timepoint?
The issue of zero z-translations is totally separate to this. Are the z-translations *exactly* zero, or just very small?
If you can supply us with this info then we should be able to help more.
All the best,
Mark
On 12 May 2014, at 20:46, Giang Chau <[log in to unmask]> wrote:
> Dear all,
>
> I am pretty new with FSL and I have some issues to understand the outputs from MCFLIRT. I am using MCFLIRT to process my time series for a fMRI experiment.
> First, MCFLIRT seems to find no translation in the z direction, which is possible looking at my data.
> I am also using the default reference volume. However, the estimated mean displacement don't go to zero at the middle of the time series and I am quite confused about that. Would it be because no translations have been found in the z-direction?
> I have only 10 slices and my voxels are pretty big (3.75x3.75x2m) and it doesn't seem like I have a lot of rigid body motion. Would that be the reason why I have these outputs?
>
> Thank you very much for your time and help!
>
> Best,
>
> Giang-Chau
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