Dear Shilpi Modi,
> This might sound to be a very basic question but I would like to know what
> is the difference between 'normalization to EPI template' and 'normalization
> with the parameter file generated after segmentation step (as given in
> example data set of SPM8 manual)' ?
>
> Which option should be used?
>
> If I use the later option doesn't it mean that, I am actually not
> normalizing all the subjects to a common template?
In both cases you are normalizing subjects to a common space (MNI
space). The difference is whether you use the functional (EPI) images
to do so, or the structural image (via segmentation).
I would guess that most people use the parameter files generated
during segmentation. However, in some cases—particularly if your EPI
images are fairly distorted—directly normalizing to the EPI template
may work better. I'm not aware of any systematic comparison between
the two, so it's hard to say which is "best" (and that probably
depends on the situation).
Hope this helps!
Best regards,
Jonathan
--
Dr. Jonathan Peelle
Department of Neurology
University of Pennsylvania
3 West Gates
3400 Spruce Street
Philadelphia, PA 19104
USA
http://jonathanpeelle.net/
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