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Hello David, what the script generates is more commonly known as "Volterra expanded" motion parameters and goes back to the classical 1996 Friston et al paper. If you search e.g. google scholar for this term, you will find some more studies using this or a similar approach, from Torben Lund, Louis Lemieux and many others. For a discussion re: pros and cons, and some simulations on the effect of using more or less covariates, you could also look at https://www.ncbi.nlm.nih.gov/pubmed/22036679 Cheers Marko David Stolz wrote: > Dear all, > > I have found a bash script by John Ashburner on the University of Warwick's website (https://www2.warwick.ac.uk/fac/sci/statistics/staff/academic-research/nichols/scripts/spm/), called mp_diffpow24, which can be used to create additional regressors for first level fMRI analysis from the usual six motion regressors. Specifically, it gives out the squares, temporal derivatives and squares of the temporal derivatives of the six motion regressors. > > I am curious whether > a) anyone has made any experience with using this (or a comparable) script, in terms of enhancing first level fMRI analysis (or if there are any systematic studies on the benefits/drawbacks of including such regressors in the first level analysis), > > b) whether there are any specific applications (MRI sequences, designs, etc) in which such a script might be recommendable to use, > > and c) whether there are any circumstances under which it is best not to use such additional regressors. > > I am not aware of any fMRI studies in which this script has been used, and I'd be happy if anyone know of some good example. > > Thanks in advance, > David > -- ____________________________________________________ Prof. Dr. med. Marko Wilke Facharzt für Kinder- und Jugendmedizin Leiter, Experimentelle Pädiatrische Neurobildgebung Universitäts-Kinderklinik Abt. III (Neuropädiatrie) Marko Wilke, MD, PhD Pediatrician Head, Experimental Pediatric Neuroimaging University Children's Hospital Dept. III (Pediatric Neurology) Hoppe-Seyler-Str. 1 D - 72076 Tübingen, Germany Tel. +49 7071 29-83416 Fax +49 7071 29-5473 [log in to unmask] http://www.medizin.uni-tuebingen.de/kinder/epn/ ____________________________________________________