I'm not entirely sure what you are doing. It sounds like you have 3 different conditions and want to find out where the activation for all conditions overlaps. But what you have done is to combine all conditions into a single condition, so you are seeing where the average activation is, which is different than the overlap (and why it looks to have to much of an extent). To do what you want to do, you should model each condition as a separate condition in mkanalysis (ie, -nconditions 3 and change your paradigm file), set up 3 contrasts (one for each condition, ie, -a 1, -a 2, -a 3), then you will need to do a conjunction analysis (mri_concat con1/sig.nii.gz con2/sig.nii.gz con3/sig.nii.gz --conjunct --o conjunction.nii.gz). You can then view the conjunction with freeview (or tksurfer/tkmedit)
On 03/20/2018 06:30 PM, nm644 wrote: > > Hello Freesurfer experts, > > My question may have already been solved in a previous thread. I have > three runs of block-design bold scans. All three are quite similar. > They all have only 2 blocks, one for rest and one for task. I’m trying > to create a functional map that displays where the functional > activation of these three runs overlap. I used the code below with no > errors: > > preproc-sess -s subj01 -fsd bold -stc up -surface fsaverage lhrh > -mni305 -fwhm 5 -per-run > > mkanalysis-sess \ > > -fsd bold -stc up -surface fsaverage lh -fwhm 5 \ > > -event-related -paradigm para.tsv -nconditions 1 \ > > -spmhrf 0 -TR 0.984 -refeventdur 24 -nskip 2 -polyfit 2 \ > > -analysis TaskOverlap.lh -per-run -force > > mkcontrast-sess -analysis TaskOverlap.lh -contrast con1 -a 1 > > selxavg3-sess -s subj01 -analysis TaskOverlap.lh > > And to display: > > tksurfer-sess -s subj01 \ > > -analysis TaskOverlap.lh \ > > -c con1 > > Or > > tksurfer-sess -s subj01 \ > > -analysis TaskOverlap.lh \ > > -c con1 -map fsig > > The problem is that when I view the output it seems that there’s far > more activation than there should be when trying to find mutual > overlap between the three tasks. If anyone has any suggestions it > would be much appreciated. > > Have a great day! > > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
