If by XYZ you mean column, row, slice, then yes. The values are with respect to the middle time point (or whatever you used as the template), it is not the relative difference. doug

On 09/12/2012 05:37 PM, New Fei Ho wrote:

Hi,

I would like to compare the mean head motion between two groups.

Just to clarify the values found in the mcprextreg file:

1. Do the six columns represent translationX, translationY, translationZ

and rotationX, rotationY, rotationZ?

2. Are the values found in each time-point (i) absolute, i.e. the absolute

difference in displacement between this time-point and the middle time-point, or (ii) relative i.e. difference between consecutive time-points?

Thanks, Newfei _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer