Hello FSL experts,
I have a question about how the high-pass filtering algorithm works. In my pre-stats report it says:
"highpass temporal filtering (Gaussian-weighted least-squares straight line fitting, with sigma=64.0s)"
My understanding is that the procedure first convolves each voxel's time-series with a Gaussian filter, and then subtracts this low-frequency component, leaving only the higher-frequency signal. Is this correct?
Is the sigma mentioned in the report the sigma for the filter in the time domain (in units of seconds), or in the frequency domain (in units of seconds/cycle)?
Thank you in advance,
Connor
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