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-----Original Message----- From: Achterberg, M. Sent: woensdag 4 november 2015 10:02 To: 'H. Nebl' Subject: RE: Artrepair and Motion Regressors Dear Helmut, Thank you for your advice! What we've now done is the second option, so replacing bad volumes by interpolated good ones. Would you then recommend including one regressor with all repaired volumes in it, or a separate regressor for each repaired volume? Thanks in advance! Best, Michelle -----Original Message----- From: H. Nebl [mailto:[log in to unmask]] Sent: dinsdag 3 november 2015 14:27 To: [log in to unmask]; Achterberg, M. Subject: Re: Artrepair and Motion Regressors Dear Michelle, I'd say you have to provide some more details on the Artrepair features you want to use for your preprocessing, as it provides several options: A very simple strategy (which I personally prefer due to its simplicity) would be to just calculate the scan-to-scan motion, then go on with the default preprocessing and add dummy regressors to the design matrices for each of the bad volumes (possibly also for the preceding and the successive volumes) when setting up the models, in addition to the rp file. This way you would model each of the bad volumes separately. As normalisation and smoothing might reduce global signal artefacts it might be better to rely on the realigned files in that case. However, you can also replace bad volumes by interpolated good ones. You would usually still want to deweight them from analysis though, as it's artificial data, and you would still add the rp files (as you "controlled" for the volumes with fast head motion but not for the slow changes over time). This might be somewhat problematic though, as the rp files might still include jerks that are no longer present in the data (because the volumes were replaced by other data, resulting in a smoother transition). Then, there's also the "Motion Adjustment" feature (see http://cibsr.stanford.edu/content/dam/sm/cibsr/documents/tools/methods/artrepair-software/MotionandDespike.pdf ), which is meant as a replacement for adding rp files. The proposed preprocessing pipeline is described in the manual. Best Helmut