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thank you, Christian. I think I understand - for my purposes, to test for spatial (not tempopral) differences, I will continue with my past approach... regards, vitaly On Thu, 16 Aug 2007, Christian Beckmann wrote: > Hi > > On 15 Aug 2007, at 17:20, Vitaly Napadow wrote: > >> hi all >> >> firstly, thanks for finally pushing this out. i think we were all chomping >> at the bit looking forward to the new release and it feels great to finally >> play with the new tools. >> >> i had completed an analysis of resting state data but want to go back and >> try the new tools now. i have 15 subjects and two separate rest runs that i >> am comparing from each subject. i assume i want to use Multi-session >> temporal concatenation to contrast the two rest runs. > > Yes, temporal concatenation is probably what you want, though you still will > need to decide on what exactly you want to compare between runs, e.g. the > amount of variance in the associated time course (as a measure of volatility) > or any other quantity you could come up with such as mean level > >> so as not to compare >> apples to oranges, i want to contrast specific resting state networks. my >> question is, if i specify and 2nd level design.mat and design.con file with >> a 1 -1 contrast how will i know which resting state networks (evident on >> group maps) are associated with or correspond to which 2nd level output >> components? > > Don't quite understand the question. In the new release version you have the > option of testing (in the GLM sense) each associated time course and each > associated session/subject mode using design and contrast matrices. The GLm > fit will be performed separately for each time course and/or subject session > mode vector. > >> >> alternatievly, if i already did single-subject analyses and have mixing >> matrices etc with components corresponding to known resting networks and >> which can be pulled out to input into a 2nd level group analysis, are my >> options to contrast on a 2nd level the same as before? > > fundamentally yes, the main difference being that in the case of separate > analyses you're bound to have differences in e.g. the default-mode network > between subjects. In the case of temporal concatenation or full TICA you > effectively fix the spatial maps to be identical and only allow the time > courses to be different. > hope this helps > Christian > >> thanks >> >> vitaly >> > > ____ > Christian F. Beckmann > University Research Lecturer > Oxford University Centre for Functional MRI of the Brain (FMRIB) > John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK. > [log in to unmask] http://www.fmrib.ox.ac.uk/~beckmann > tel: +44 1865 222551 fax: +44 1865 222717 > > > -- |`~~~~~~~~~~~~~~~~~\|/~~~~~~~~~~~~~~~~~'| Vitaly Napadow, Ph.D., Lic.Ac. Assistant Professor Martinos Center for Biomedical Imaging Massachusetts General Hospital CNY 149-2301, 13th St. Charlestown, MA 02129 phone: (617) 724-3402 fax: (617) 726-7422 www.nmr.mgh.harvard.edu/~vitaly |`~~~~~~~~~~~~~~~~~/|\~~~~~~~~~~~~~~~~~'|