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According to Gareth, EBB also has a tendency to at least bias the locations to be the same across conditions so it's not unreasonable. Vladimir On Wed, Aug 26, 2015 at 6:27 PM, Jane Kouptsova <[log in to unmask]> wrote: > Vladimir, thank you for your quick response. I am using EBB - is this > assumption also true here, or would my results be unusual for this > algorithm? > > Thanks, > Jane > > On Wed, Aug 26, 2015 at 12:29 PM, Vladimir Litvak < > [log in to unmask]> wrote: > >> Dear Jane, >> >> If you are using the MSP method (GS or ARD options) running it on the >> three conditions combined this makes a lot of sense as this method assumes >> that the same sources are active in all the conditions, just their level of >> activation differs. So the algorithm will try to find sources that can fit >> all the three conditions. If you select e.g. the 'IID' option, this should >> not be the case. >> >> Best, >> >> Vladimir >> >> On Wed, Aug 26, 2015 at 3:47 PM, Jane Kouptsova <[log in to unmask]> >> wrote: >> >>> Dear all, >>> I am running an MEG analysis using SPM12, where I look at differences >>> between three conditions, say 1, 2 and 3. When I run contrasts, I expect >>> 3vs1 and 3vs2 to give similar results, and this is what I'm getting, >>> however, more than being similar, many of the cluster peak coordinates are >>> identical. Is this a cause for concern? >>> >>> The Z, D-uncorr and other values from the contrast are slightly >>> different even when peaks are identical, and running a 1vs2 contrast also >>> gives some results. So I know I didn't accidentally assign the same set of >>> trials to both conditions. Is there anything else I should check to be sure >>> of the output? >>> >>> Many thanks, >>> Jane >>> >> >> >