Hi Philipp,

Actually, the point of -regress_compute_fitts is simply to save RAM, it has nothing to do with the analysis type. The fitts dataset is computed in general, and that option means to compute it *after* running the regression, not during.


Thanks for the update on the number of baseline terms. I did expect them to be close. But the sinusoids should be better behaved for these long runs.


Using polort 2 with that high-pass filter is intending to do the same thing as with the high-degree polort: to model slow fluctuations in the time series, due to things like coil temperature.

There is no intended theoretical difference between the 2 methods. It is just that at such a high degree, polynomials are not so well behaved. But notably, polynomials can drift into the higher frequency spectrum, sinusoids cannot. On the flip side, all such artifacts aren't necessarily in the lower spectrum. Such is life.

- rick