Here I expalin how to do FIR analysis with SPM. The sample data is a fMRI experimnt with 42 trials The TR=2.2 and Interstimulus is about 14 to 17 sec which is a slow event-related design
The data are preprocessed with realignment and normalization and smoothing with 8mm. The data can be downloaded from the link: https://www.dropbox.com/s/mi97qstsfyqxne2/swrf.nii?dl=0
I put the statistical analysis of one conditions to replicate the results you need spm12.
The FIR windows is 10 sec and the number of the boxcar functions are 5