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Yes, I reorientated the EPIs by 4 cm, if some of the EPIs would not have been changed, the plot scale would be completely different. Differently, for one of the three parameters, the shape of the curve is the same but the amplitude is bigger. The other two parameters changed both in shape and amplitude. As a wrote below, only the translation parameters change. I know, but should I use the 6 from the original realignment or from the one after the reorientation. Best, Stefan On 13.06.2013 18:58, Chris Watson wrote: > Are you sure you applied the reorient changes to all images? > How much did the movement parameters change? > If you are going to add as regressors, add all 6. > > On 06/13/2013 11:54 AM, Stefan Greulich wrote: >> Deer all, >> >> I have run into a strange behaviour of SPM and might need some help. >> I am a master student and run a fMRI study, and on one subject I had >> to us the reorientate procedure to reset the point of origin into the >> AC. This was necessary, to get usable results from the segmentation >> process. But when I applied the reorientation to all the EPIs of the >> subject, the movement parameters, which are estimated by the >> realigment module changes. As it is my understanding, that the >> realignment procedure only gives you relative movements (in my case >> to the first EPI), how is this possible? >> The reorientation happens in the y and z axis and the change affects >> all translation parameters, but not the rotation parameters. >> I also would like to now, which one of the movement parameters should >> I use for ascertaining the subject movement and as regressors in the >> analysis? >> >> Many Thanks in advance, >> Stefan Greulich >> >