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
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