Hi,
I would like to investigate whether the differences between structural connectivity matrices across subjects imply a different response to tDCS.
From literature I can’t find a ‘good practice’ to properly compare the SC in output from tck2connectome, or whether there is the necessity to normalize SC.
So far, I normalize the wm fod with mtnormalise, then I filter the whole brain tractogram with tcksift2 and in the end I obtain the SC with tck2connectome. Shall I do something else in order to compare SC matrices across subjects?
It all comes down to the exact analysis you want to do, but assuming you want to perform edge-wise comparison (NBS or something similar), you need to have a couple of “extra steps” in to account:
First of all, you need to use the same response function with all your subjects.
Second, you need yo multiply each connectome by their mu coefficient, obtained from tcksift2.
If you do this, you can compare the connectomes edge-wise, but also for example global network metrics. I hope this helps.
Thanks for the reply!
I have another doubt for what concerns the response function. I have normalized the RF for each subject with mtnormalize, is it okay or should I use the same RF for every subject?
Thanks in advance,
Giulia