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Dear Drew, For each subject you could first collapse DCMs from multiple sessions to a single session using BPA. You can then run the procedure described below. All the best, Will. > -----Original Message----- > From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] > On Behalf Of Sevel,Landrew S > Sent: 19 September 2013 17:37 > To: [log in to unmask] > Subject: Re: [SPM] BPA, BMA v/s FFX, RFX > > Professor Penny and others, > > For a procedure like the one mentioned below, are there any guidelines > for incorporating subjects with multiple sessions? > > For example, BMS results favored one model across this group, how then > would I average to acquire parameter strengths and probabilities across > this group with multiple sessions? > > Best, > > Drew > > On 9/18/13 5:05 AM, "Penny, William" <[log in to unmask]> wrote: > > >Dear Kushal Kapse, > > > >Here I would advise using Bayesian Model Averaging to first average > >over model space. > > > >This will produce a single vector of model parameters for each > subject: > > > >w=BMS.DCM.rfx.bma.mEp > > > >You can then do t-tests, F-tests or multivariate tests to look for > >consistency of effects over a group of patients or eg. two-sample > >t-tests to look for differences between patients and controls. > > > >Best wishes, > > > >Will. > > > >> -----Original Message----- > >> From: SPM (Statistical Parametric Mapping) > >> [mailto:[log in to unmask]] On Behalf Of Kushal Kapse > >> Sent: 05 September 2013 17:16 > >> To: [log in to unmask] > >> Subject: [SPM] BPA, BMA v/s FFX, RFX > >> > >> Hi Peter and SPM users, > >> > >> Two months ago we had email conversation about my doubts on DCM. I > >> finished the analysis and now working on interpretation. I went > >> through the DCM tutorial and BMA paper to get understanding on what > >> way to interpret my datasets. I read the book section > >> http://www.fil.ion.ucl.ac.uk/~wpenny/publications/spm- > >> book/selection.pdf to understand BMA and BPA. But i have following > >> question: > >> > >> 1- We are specifically looking to understand connectivity in brain > >> across treatment. This makes us incline to use parameter estimates > >> over model estimates (BPA over BMA). BUt seems we can only do BPA if > >> we select FFX and BMA if we select RFX. Why is this? Can I do RFX > and > >> then perform BPA? The reason to use RFX is that we are expecting > >> different cognitive network for each patient. But we want to do > >> Bayesian Parameter Averaging to interpret how patients connectivity > >> changes as a measure of treatment across two scans. > >> > >> SO my question is , can i do BPA using RFX. > >> > >> Your advice will be really helpful again. > >> > >> THanks > >> > >> > >