I am afraid that you cannot do this through the GUI, but I have
attached a script which should be able to do the trick. Select one or
more rp files with the movement parameters you want to expand, and the
script will return files vxrp*txt containing the Volterra expanded
motion parameters. This file can then be selected via the GUI under
Torben Ellegaard Lund
Assistant Professor, PhD
The Danish National Research Foundation's Center for Functionally
Integrative Neuroscience (CFIN)
Aarhus University Hospital
8000 Aarhus C
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On 13/12/2007, at 20.28, Simon Glynn wrote:
> Dear SPM list
> I'd be grateful for your help. I've not found this on the list; I
> apologise if I've missed this, or if this is trivial.
> Several papers describe that intra-session and inter-session
> variability may be improved by using a Volterra expansion of the
> movement parameters as covariates of no interest in the GLM. For
> example -
> Lemieux L, Salek-Haddadi A, Lund TE, Laufs H, Carmichael D,
> Modelling large motion events in fMRI studies of patients with
> epilepsy, Magn Reson Imaging. 2007 Jul;25(6):894-901.
> Lund TE, Nørgaard MD, Rostrup E, Rowe JB, Paulson OB., Motion or
> activity: their role in intra- and inter-subject variation in fMRI.
> Neuroimage. 2005 Jul 1;26(3):960-4.
> Can this expansion be done in the design specification (using the
> GUI for spm5) for covariates of no interest?
> If no, can the spm_Volterra.m script be used with the rp_*.txt file
> to create the file of expanded movement parameters?
> Many thanks for this;
> Simon Glynn
> Fellow, Epilepsy
> University of Pennsylvania