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Helmut, I agree with your suggestion, it would be good to have a function that updated the rp-file by replacing the realignment parameters for the volumes that were repaired. The function would help support users who run only art_global, and then add realignment parameters to the GLM. If you wrote such a function, it could be added to the toolbox. The six realignment regressors commonly used in the GLM are a "motion adjustment" approximation valid for small motions. ArtRepair includes a special built-in function for motion adjustment because some pediatric and clinical subjects have slow large amplitude motions (>2 mm). The corrections for large motion uses voxel-wixe regressors that are periodic in raw voxel size (see theory in Grootoonk, 2000). ArtRepair calculates these regressors after first discarding the spike volumes in order to improve the accuracy of the realignment calculations. Thus, all volumes will either be repaired or accurately realigned including the small adjustments that compensate for interpolation errors. Then there is no need to add motion regressors to the GLM design. Best regards, Paul ----- Original Message ----- From: "H. Nebl" <[log in to unmask]> To: [log in to unmask], "Paul Mazaika" <[log in to unmask]> Sent: Tuesday, July 28, 2015 4:18:08 AM Subject: Re: ArtRepair Toolbox installation/Use Dear Paul, As this might be interesting for future versions: In case of fast head motion the overall shape of the brain would be "distorted" as well due to spatially "shifted" slices within the volume, accomplishing the rigid-body registration in SPM during realignment, and affecting the rp estimates and the mean image. It might be worth a try to go with realigned data, determine the bad volumes, discard them, rerun realign on the raw data minus the bad volumes (if one wants to realign on the mean image this should be a little more precise, as the mean image is based on "good" data) and add interpolated volumes plus corresponding values into the rp file where necessary. This way one would avoid abrupt jerks stored in the rp file although the corresponding volumes have been removed from the data by adding interpolated volumes (thus basically trying to predict something that has already been removed from the data series). I'm aware of additional options in Artrepair, e.g. the slice-wise correction, which might already compensate well for displacement of slices within volumes. But the approach as described above *could* also be useful. Best Helmut