Hi Laura,

I will try to rewrite your timing with the modern usage,
just for demo. However, I do not see in your example
where the NULL events are.

Each run is 690s, of which 480 are for task, 140 for
NULL trials, and 10 for post stim time. That accounts
for 630s, leaving only 60s for ISI. Attaching the ISI
to the 40 non-NULL events per run makes the average ISI
1.5s.

So consider such things in this MRT.py command:

set seed = 1234567
set iter = 001

make_random_timing.py -num_runs 4 -run_time 690 \
        -tr 2                                   \
        -pre_stim_rest 0 -post_stim_rest 10     \
        -rand_post_stim_rest no                 \
        -add_timing_class stim 12               \
        -add_timing_class tnull 10              \
        -add_timing_class rest 0.5 1.5 4 dist=decay_fixed \
        -add_stim_class NMA 10 stim rest        \
        -add_stim_class NMS 10 stim rest        \
        -add_stim_class HMA 10 stim rest        \
        -add_stim_class HMS 10 stim rest        \
        -add_stim_class NULL 14 tnull INSTANT   \
        -write_event_list events.$iter.txt      \
        -show_timing_stats                      \
        -seed $seed                             \
        -prefix threat_app.$iter                \
        -save_3dd_cmd cmd.3dd.$iter.txt

Note that the NULL events might have ISI time before
them, but not after, as the attached ISI is INSTANT
(meaning zero time).

View the text file events.001.txt for the list of events
across all runs.

I will put this in @stim_analyze_modern at the same
location, just as an example. I will probably updated
it to be more complicated later. Maybe.

- rick