Hi Shaquanda,
> As is often the case, I can find all sorts of theoretical information about how to do VBM (e.g. formulas, etc.) but I cannot find any examples or workshop data sets of how actually do to VBM statistics on using SPM?
Sometimes finding out exactly ho to actually do things is hardest
(partly because there are many different ways to do it :) Generally,
what you do after you processed your images (which has become one hell
of a lot easier in spm5, so I really recommend you use that version) you
do a statistical comparison by entering your data into a second-level
statistical model. For example, if you want to compare two groups
(patients vs. controls) you could
click on segment, select all subject
Output files: unmodulated normalized GM
run segment
click on smooth, select all wc1*.img
smoothing width, say, 12 x 12 x 12 mm
run smooth
click on second level statistical model
select 2-sample-t-test
select patients as one group, controls as the other
run stats
click on results, define your contrast (e.g., 1 -1 or so)
correct for multiple comparisons (recommended unless you have VERY
convincing arguments to the contrary)
see group differences
publish
I admit that this is not the whole story and there may be some more
bumps in the road but perhaps it gets you started. Also try the spm
manual, it is very helpful to understand, for example, what options to
choose during segmentation, or smoothing, or stats.
Good luck :)
Marko
--
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Marko Wilke (Dr.med./M.D.)
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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
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