Hello,

I am using a seed region in the PCC. I would like to isolate myself to looking only at correlations (or Z-score values as I did a Fischers Z transformation) within the DMN based on a standard DMN template that I have.

I am assuming that the first thing that I do is use 3dcalc and multiply the whole brain correlational map with the DMN mask? Although that won't retain the values and will turn everything into 0s and 1s right?

I used the following script: 3dcalc -a thresh_zstat_3.5+tlrc -b Corr_${subject}_dist_PCC_Z+tlrc -expr 'ispositive(a)*b' -prefix Corr_${subject}_dist_PCC_Z_DMN+tlrc

However I got an error message: dataset Corr_10112_dist_PCC_Z+tlrc differs in size [108790 voxels] from others [101200].

After I am able to obtain the DMN for each subject. I would like to calculate a mean Z score for each subject as an index of general overall connectivity in the DMN. Would I use potentially 3dTstat or 3dmean to obtain this? I saw this type of analysis in an ICA paper and thought this could be useful and could be applied to more of a seed based analysis.

I would appreciate any guidance you can give me.

Thanks,

Emily