Hi Jonas! I am trying to do the same thing, but I have a problem fitting the peaks of the PSD with both periodic and aperiodic components and calculating their center frequency and amplitude. It seems that there is no similar function in brainstorm. How did you solve this problem? Look forward to your reply.
I also hope that @Luc can provide some suggestions on fit peaks of original PSD. I tried to use the code in Brainstorm to do it, but it failed. (Questions about fooof).