Ines,
the idea behind not doing both was supported some time ago by Jesper,
based on the assumption that, if you already modeled motion effects
during unwarping, you should not have to model them again in the
statistical part. It is not very likely to hurt much, given that motion
may explain 50-80% of the observable effects in your data, but it may be
too strict. For an alternative towards modeling motion in fMRI, you
could look into PMID 22036679 (which, I should add as a disclaimer, is
my own idea).
Cheers,
Marko
Mürner-Lavanchy, Ines wrote:
> Hello,
> I’d like to know if it is nessecary or useful to integrate motion as a
> covariate in my analysis, if I previously unwarped my data.
> I heard that this would be redundant but I don’t exactly understand why.
> Thank you very much in advance
> Ines
--
____________________________________________________
PD 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
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