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Thanks a lot for your explanations Marko! This is really helpful :) I'll start rigth now installing TOM... Best wishes, Álvaro On Thu, 26 Nov 2009 11:50:41 +0100, Marko Wilke <[log in to unmask]> wrote: >Hi Alvaro, > >> -I downloaded TOM from your site some days ago, but I didn't try it yet >> because I wanted to use SPM8. Then is it possible to generate the priors >> with TOM and SPM5 and then use them in SPM8 (replacing the apriori folder >> files), or should I process all the analysis with SPM5? > >There is no need to do that, you can use the templates generated in spm5 >in spm8. We are working on a dedicated TOM for spm8 but are not quite >there yet. You should not replace any files coming with spm; instead, >the segmenttion routines allow you to specify your own tissue >probability maps. This is where you should select the custom priors. > >> I have read that it's possible to generate your own template using your own >> T1 images, I'll try to do that. > >... if you have a large-enough sample. To anticipate the next question, >nobody knows what "large enough" is, but I would go for triple-digit >numbers if at all possible. > >> -Can I ask a couple of basic questions more? >> Do researchers use "uncorrected" option when showing activation maps, or is >> it more trustworthy to use FWE or FDR? > >You do several thousands of comparisons, so correcting for those massive >numbers is required, in one way or another (search the list for "small >volume correction", FDR, cluster extent...). As I said, you need to be >able to justify what you do. > >> The voxel extent threshold sets the minimum size of the clusters that will >> be shown. Does it work only after the statistical map is calculated, merely >> not showing the clusters smaller than the value? > >Basically, it suppresses small clusters, but there are also approaches >that combine cluster extent and voxel values, so there is no easy answer. > >> Have a nice day :) > >You too (all of you :) >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 >=====================================================================