Hi Shaquanda,
> Thank you. Your response was lucid and extremely helpful. A couple more questions if you don't mind.
There is always "one more question" :)
> Yes, this is the great part about SPM, i.e. the flexibility. However, just doing the basics is often quite difficult to figure out from the documentation and the GUI.
I think part of the lack of clear-cut "do this first, then this, then
this" explanations is that a lot of this simply is not clear-cut. You
would have to write "do this (or this), then this (or that, in case you
have done this as the first step), then, depending on step 2, do ..."
which tends not to turn out to be lucid at all.
> Ok, since we are just beginning to learn VBM - can you clarify broadly which pre-processing steps we should be doing? My sense is that this can be a bit different for VBM versus fMRI, but that as you say it has become a lot easier in SPM5 (which is indeed what we are using).
It certainly is different, but for VBM, quite simple: you segment your
images (T1 hi-res, preferrably) and set the options to write out
normalized or modulated normalized segmented images to your liking
(which you are interested in depends on your question, I am not going to
go there :) You then smooth the images, typically with about 12 mm
(except if you are interested in smaller structures when, according to
the matched filter theorem, you would use a smaller filter) and then
feed them to statistics. It really is that simple :)
> publish
>
> That is the part where you used to be able to just pull the lever on the "SPM 99 machine" and the paper will pop out right?
Yes, I think that as part of the upgrade process, this lever was removed
from spm2/5. Shame :)
> Absolutely - fortunately there is a lot of information regarding the theoretical underpinnings of all of these techniques which I agree are essential to understand.
It certainly helps (I heard :)
> Your directions for describing how to implement analysis are extremely helpful, especially when entering into a new area with which one is unfamiliar.
In imaging neuroscience, we really all are beginners in some way. As for
practical hints, I found the list archives to be extremely helpful.
Best,
Marko
--
=====================================================================
Marko Wilke (Dr.med./M.D.)
[log in to unmask]
Universitäts-Kinderklinik University Children's Hospital
Abt. III (Neuropädiatrie) Dept. III (Pediatric neurology)
Hoppe-Seyler-Str. 1, D - 72076 Tübingen
Tel.: (+49) 07071 29-83416 Fax: (+49) 07071 29-5473
=====================================================================
|