afni.nimh.nih.gov

The fico calculation includes baseline regressors, which you aren't including in the THD_fitter() analysis. You didn't say what your application is. You need to understand that the GLM analysis includes regressors of no interest (AKA 'baseline' or 'null hypothesis' regressors), in addition to the hemodynamic model response to stimulus.

For more background on this subject, see

[afni.nimh.nih.gov]
[afni.nimh.nih.gov]

and the '05', '06', and '07' presentations in the same directory.