Hi all,
I want to apply ICA denoising for 4d data during the preprocessing using FSL. The question I have is about high-pass filtering for design matrix.
For ICA denoising, it is recommended to apply HPF first, then do denoising. When I run the first level GLM in SPM with this already-HPF-filtered image, then, it is simply okay to turn off the HPF in SPM with 'inf' option? (https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0908&L=SPM&F=&S=&P=173905)
My concern is about design matrix without HPF. I did do some research for previous posts, found some inconsistencies for this idea.
Given the different approach of HPF between FSL and SPM, there was a slight difference in therms of time-series when I applied the same cut-off highpass filter through SPM for fsl's prefiltered data.
Is there a way to apply HPF only for design matrix (FSL can do this), or what do you think using the same cut-off HPF during the first level GLM in SPM instead of 'inf' (although there is slight time-series change; please see attached: green indicates re-applied HPF in SPM, and red indicates ICA denoised and HPF applied time-series by FSL).
I would appreciate any comments!
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