Hello Ursula, if I follow your reasoning I doubt option B makes sense given that you seem to be removing specific components from each run. However, realize that the components you are removing were estimated across all runs. Therefore removing some components from some runs, but not others would be inappropriate. Optimal in option B would be to run fsl_regfilt across your concatenated runs. hth Maarten On Thu, Nov 5, 2015 at 9:19 PM, Úrsula Pérez <[log in to unmask]> wrote: > Hi all, > > I am participating in a resting-state fMRI study. Before group ICA, I > would like to remove some non-interest independent components for each > subject (5 runs with 90 volumes each one), applying Melodic and > fsl_regfilt. Each run has been preprocessed separately. > > I am considering two options, for each subject: > > A) Melodic for each run, obtain ICs and fsl_regfilt for each run > (5 times because there are 5 runs) > > B) Melodic with a list of the 5 runs as input and obtain ICs. > Then, apply fsl_regfilt to each run. For that, it is necessary to > split melodic_mix in matrices of 90 rows (because each run has 90 volumes), > i.e. > fsl_regfilt -i run1 -o run1_denoised -d melodic_mix_rows1to90 -f "1,2" > fsl_regfilt -i run2 -o run2_denoised -d melodic_mix_rows91to180 -f "1,5" > fsl_regfilt -i run3 -o run3_denoised -d melodic_mix_rows181to270 -f "8,2" > fsl_regfilt -i run4 -o run4_denoised -d melodic_mix_rows271to360 -f "7,2" > fsl_regfilt -i run5 -o run5_denoised -d melodic_mix_rows361to450 -f "9,2" > > I prefer option B because it requires less workload to identify good or > bad components, and also because maybe one run is not enough for ICA. > > Please, could you tell me if option B is correct? > > Thank you very much, > All the best, > > Úrsula > -- Maarten Mennes, Ph.D. Senior Researcher Donders Institute for Brain, Cognition and Behaviour Radboud University Nijmegen Nijmegen The Netherlands Google Scholar Author Link <http://scholar.google.com/citations?user=pLlSTVgAAAAJ&hl=en>