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!