Dear FSL experts,
I am interested in figuring out functional connectivity between sub-components of independent components (IC) by MELODIC.
For instance, I am interested in functional connectivity between pcc and IPL/IPS within DMN.
The first method I tried was to simply increase the number of IC to be identified in MELODIC (from 25 to 60/70), in hopes of replicating the Smith PNAS 2009 paper. However, DMN did not seem to break down - It still emerged as a single IC.
The second method I am thinking of is 'manually' breaking down the ICs. I would break down DMN into several sub-regions manually using masks and re-integrate them as 'separate components' into the dataset to be fed into dual regression. This was suggested a while ago in this forum.
Following this, I have two questions.
1. In the first method, is simply increasing the number of ICs not the correct answer to get the sub-regions?
2. Perhaps more important, is the second method valid? I am worried that manually breaking down the components will violate the spatial independence between components, which is the very premise of ICA/MELODIC.
Thank you very much,
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