Hi,
It is well-known that depending where we choose seed region of the DMN (e.g.., PCC or mPFC) we can get major difference between the networks. Why is that? If region A was correlated with region B, then it does not matter which of them was seed. Is it because the network we get is a statistical map? So, for example, the most strong correlation of A is with B. But B, has stronger connection with C. So, the when A is a seed I will see the B. But When B is the seed I will not see the A.
Also, if someone can send me a a good paper whcih compared DMN obtained with different seeds I will really appreciate.
Thanks a lot,
Vadim
Hi Vadim,
Hi Vadim,
If you extracted time courses of Region A and Region B, then the correlation doesn't depend on which is seed.
However, if you use voxel-wise functional connectivity maps, it's slightly different because of the averaging within the ROI.
For studies compare DMN subnetworks, you can refer to
Damoiseaux, J.S., Rombouts, S.A., Barkhof, F., Scheltens, P., Stam, C.J., Smith, S.M., Beckmann, C.F., 2006. Consistent resting-state networks across healthy subjects. Proc Natl Acad Sci U S A 103, 13848-13853.
Andrews-Hanna, J.R., Reidler, J.S., Sepulcre, J., Poulin, R., Buckner, R.L., 2010. Functional-anatomic fractionation of the brain's default network. Neuron 65, 550-562.
Best,
Chao-Gan
Thanks for your answer!
Actually, this is not what I meant, but I think I now better understand what I misssed. Below is the example. I have seed ROI in left PHC (first row). It is strongly connected with regions in its proximity, but also with some more distant regions like mPFC (right row). Now, I use the ROI in mPFC (bottom raw). Obviously, because this is ROI and not a single voxel it is not 100% exact, but I mean the principle. The mPFC is also strongly connected with regions in its proximity. Critically, we can see that it is connected with left PHC. So, if A is used as seed and it is connected with B, then when B is used as a seed it must be connected with A. However, if A is connected with B, and A is connected with C (some other region), this does not imply that B will be also connected with C. The fact that left-right PHC are strongly connected, does not guarantee that mPFC would be connected with both of them.