Dear Christian (Beckmann),
a very quick question: does the current version of melodic (3.10) perform voxel-wise temporal demeaning? I was reading a recent paper you co-authored (Remes et al, Neuroimage, in press), that said that melodic did not demean the time series up to version 3.09. I browsed the FSL list and found two somewhat conflicting statements about this (posted on the same day, 18 June 2010):
1) Re: ICA global signal question
"melodic does not remove the mean time course - though you can request this to happen using the --remove_meantc command line option"
2) Re: Melodic ICA question
"time courses are demeaned and then subjected to variance normalisation, i.e. scaled by a robust estimate of the voxel-wise residual noise std deviation"
thanks for any clarification (and congratulations for the paper!)
giuseppe
|