Hi CONN experts,

I normally do a regression in my fMRI data to mitigate the effect of nuisance variables/regressors (e.g. movement, physiological artifacts, white matter, csf, etc.). Sometimes I am also interested to do a band pass filter.
I have read that the correct way to do a "Nuisance regression" with a band pass filter is including the band pass in the regression model. So, all the operations can be done in a single step.

The real problem appears when I try to band pass the data at "0.002 - 0.01"  and "0.012 - 0.028".
It seems that band passing at those frequency ranges use at least more than 90% of the degrees of freedom of the data set. Then, if I have more regressors (movement parameters, physiological recordings, etc.) it is not possible or does not make sense to do the regression because the number of regressors exceeds the number of time points.

How could I deal with this problem if I am interested in keeping bandpass in the regression model?

Best regards,
Karel