Hi Rick,

Thank you for the reply. The basis functions used will be those specified in these papers:

Chang, C., Cunningham, J. P., & Glover, G. H. (2009). Influence of heart rate on the BOLD signal: the cardiac response function. Neuroimage, 44(3), 857-869.

Birn, R. M., Smith, M. A., Jones, T. B., & Bandettini, P. A. (2008). The respiration response function: the temporal dynamics of fMRI signal fluctuations related to changes in respiration. Neuroimage, 40(2), 644-654.

Basically, I will generate the slice-based HR and RVT time-series, convolve that time series with the respective basis function (as above), and then regress out these as nuisance regressors from the data.

Do you have a suggestion as to how I should include this additional set of regressors into my afni_proc.py script? I have them as slice-based regressor 1D files, similar to the retroicor regressor 1D files.

Thanks.