Dear melodic experts,
we are currently confronted with a reviewer's opinion that states, IC maps are
per se not "normally distributed" and cannot undergo any voxelwise statistics.
This we had done on Z-maps gained from individual ICAs (using the
melodic_IC.img/hdr) after an automated component selection step, as e. g. in
the work of Greicius et al. Resting-State Functional Connectivity in Major
Depression: Abnormally Increased Contributions from Subgenual Cingulate
Cortex and Thalamus, Biol Psychiatry, 2007; or in other work on clinical
samples (e. g. Alzheimers disease, Sorg et al.)
We understood from the description of FSL that the raw IC values are divided
by the residual noise from the dissection into ICs, that results then in the Z
Can these Z maps can be subjected to voxelwise comparisons, typically using
ANCOVAs (across subjects, e. g. 20 of a group A against 20 of a group B)?
We are grateful to any comments on this issue -
thank you very much in advance!