afni.nimh.nih.gov

That program does not get much use, certainly including by
me. And while the help suggests your usage might be okay,
after a little playing, I do not see how.

Consider David's example from two years ago. That seems
to work.

3dConvolve -input zero_template+orig       \
      -polort -1                           \
      -num_stimts 1                        \
      -stim_file 1 stim_doughnuts.1D       \
      -stim_maxlag 1 14                    \
      -iresp 1 iresp_doughnuts+orig        \
      -output convolved_result

- rick