Hi, all

I have question
about removing liner trend. In your functional data preprocessing pipeline, you
don’t remove liner trend. But in many papers, they often regard it as noise and
remove it. Do we need to remove it by ourselves?

Another question
is that when we use fast Fourier transform (FFT) to the time series which from
AAL templates, we find that there are relatively high power spectrum below
0.01Hz, but the data were band-pass filtered (0.01-0.08Hz). Why?

thank you very much for your help!!