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Hi All, I am trying to replicate the methods from the Damoiseax 2008 Cerebral Cortex paper, and thanks to Christian Beckmann and the other members of the list, I am getting closer. I have converted smoothed, normalized fMRI data of a resting state run (TR2.5/300s/120vols) into power spectral information using fslpspec. This results in 60 volumes representing different frequency bins written in a nii.gz file (Christian posted how to calculate the bins - many thanks). I am having difficulty running the TICA - the gica log said it wasn't converging at the PCA step - so I backed up and tried to run single-session ica on one subject. If I enter this data into melodic in FSL 4.0, the program seems to be overwriting the nii.gz file, so that the power spectral data is lost. An error is then thrown that either says that the PCA failed to converge or that the data set is empty. If I enter the data into melodic in FSL 3.2, it will run, but it usually results in between 1-4 components that are not apparently biologically meaningful. We also tried omitting the first volume of the spectral data, as it is very low frequency and seems to have a lot of noise, but this did not change the results. I am wondering if I am entering the correct information into the GUI. I have tried entering the actual TR and a TR of 0.0, running melodic with and without functions like BET and MCFLIRT, and using various hpf or turning it off altogether. We are planning on Monday to try creating the power spectral data in another way to see if there is a problem with the pspec files themselves, for some reason, but I was wondering if anyone had had similar problems, or can see an obvious mistake(s) that I am making. Thank you so much for any advice you can offer! I am very interested to see the results of this analysis. Thanks, Christina