It's been mentioned before that melodic_oIC contains the "raw" IC maps, that melodic_IC contains the Z-scaled IC maps, and that Noise_stddev_inv is used to convert the former to the latter. I'm curious as to precisely how this conversion is achieved. That is, given melodic_oIC, how do I get melodic_IC? The IEEE TMI paper seems to suggest it is a simple matter of doing voxel-wise division of each raw IC map by the standard deviation of the noise (technically the square root of the estimate of the noise variance), so: http://www.fmrib.ox.ac.uk/analysis/techrep/tr02cb1/tr02cb1/node8.html
fslmaths melodic_oIC -mul Noise_stddev_inv my_melodic_IC
But this doesn't seem to work. Indeed, lines 519-548 of meldata.cc would suggest something more is happening. Can anyone explain how to get melodic_IC from melodic_oIC using fslmaths?
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