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Hi Andreas, Probably it's simpler than that - if your original models in FEAT had the same initial heights, and the contrasts were equivalent, then you should be able to compare these across runs in general (though of course caveats when comparing across different stimuation periods, e.g. block vs brief events is problematic...) Cheers. On 8 Jul 2009, at 08:16, Andreas Bartsch wrote: > Thanks, Steve! > So you mean we should check in the design.mat? > > Cheers! > > Andreas > ________________________________________ > Von: FSL - FMRIB's Software Library [[log in to unmask]] im Auftrag > von Steve Smith [[log in to unmask]] > Gesendet: Dienstag, 7. Juli 2009 21:10 > An: [log in to unmask] > Betreff: Re: [FSL] FE across sessions with slightly different > paradigms > > Hi, > > Yes, this sounds fine to me - as long as the 'height' of the first- > level model*COPE can be considered comparable across sessions. > > Cheers. > > > > On 5 Jul 2009, at 12:46, Andreas Bartsch wrote: > >> Hi, >> >> I have a rather general question about second level FE analyses: >> Is it legitimate to run a within-subject FE analysis across sessions >> with slightly different paradigms and tasks? >> Background: We have 3 session per subject (n~30) and each session >> was recorded under a slightly different paradigm / task. However, >> the sessions share certain main EVs and we were thinking to run a FE >> for these to get more robust and somewhat context-independent >> results. >> I can see that this will all depend on whether the assumption of a >> context-independent component to each run holds true but other than >> that does a FE in such case sound ok? Or would people strongly favor >> a 'conjunction'-type of analysis here? >> Thanks + cheers- >> Andreas >> > > > --------------------------------------------------------------------------- > Stephen M. Smith, Professor of Biomedical Engineering > Associate Director, Oxford University FMRIB Centre > > FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK > +44 (0) 1865 222726 (fax 222717) > [log in to unmask] http://www.fmrib.ox.ac.uk/~steve > --------------------------------------------------------------------------- > --------------------------------------------------------------------------- Stephen M. Smith, Professor of Biomedical Engineering Associate Director, Oxford University FMRIB Centre FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK +44 (0) 1865 222726 (fax 222717) [log in to unmask] http://www.fmrib.ox.ac.uk/~steve ---------------------------------------------------------------------------