Hello,
Note the AM1 with dmUBLOCK will indeed result in both varying heights and shapes for individual events, if that is what you are asking about. The BLOCK basis function gets convolved with boxcars of the varying durations, which will result in both of those differences. The BLOCK basis function does not have an undershoot though, as you show in the images.
The -polort default is 1 + floor(run_length/150 (time in seconds)), also applied by afni_proc.py (unless otherwise specified by the user).
What is the range of stimulus duration applied? Consider:
timing_tool.py -multi_timing Ant*.1D -multi_show_duration_stats
- rick
