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May 09, 2022 11:55AM
Hi Philipp,

To be sure, are you really acquiring a single run that is more than an hour long, without any breaks in the scanning?

In such a case, it might be better not to use polor detrending, but rather sinusoid. It might include a similar number of regressors, but be better behaved.

That would be doing bandpassing, but only as a high-pass filter. But since BP does not really account for quadratic trends, also include polort 2. For example, consider something like:

-regress_polort 2         \
-regress_bandpass 0.01 1

Here the upper frequency of 1 could be anything at least as large as your Nyquist frequency of 0.25 Hz.


You would have to verify how many regressors this would end up corresponding to, it might still be similar.


On a separate note, if you want to decrease the RAM needs for this, consider adding -regress_compute_fitts .

- rick
Subject Author Posted

AFNI proc -regress_polort option for very long runs

Philipp May 07, 2022 08:47AM

Re: AFNI proc -regress_polort option for very long runs

rick reynolds May 09, 2022 11:55AM

Re: AFNI proc -regress_polort option for very long runs

Philipp May 09, 2022 12:32PM

Re: AFNI proc -regress_polort option for very long runs

rick reynolds May 09, 2022 02:08PM

Re: AFNI proc -regress_polort option for very long runs

Philipp May 09, 2022 02:17PM

Re: AFNI proc -regress_polort option for very long runs

rick reynolds May 09, 2022 02:39PM

Re: AFNI proc -regress_polort option for very long runs

Philipp May 09, 2022 02:44PM

Re: AFNI proc -regress_polort option for very long runs

rick reynolds May 09, 2022 02:51PM

Re: AFNI proc -regress_polort option for very long runs

Philipp May 09, 2022 02:58PM

Re: AFNI proc -regress_polort option for very long runs

rick reynolds May 09, 2022 03:31PM

Re: AFNI proc -regress_polort option for very long runs

Philipp May 09, 2022 03:35PM

Re: AFNI proc -regress_polort option for very long runs

rick reynolds May 09, 2022 04:10PM



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