Hi Rick,

Thanks for your thoughtful response and for making me aware of the newer advanced options, which have been a wonderful improvement over the older version that I was trying to implement. I'm just having one issue, which is related to TR-locking. Unfortunately this is necessary at this time. I am collecting concurrent eye movement data and my stimulus display program must initiate trials based on a TTL pulse from the scanner. Currently, our scanner only sends TTL pulses at each TR (we are working on changing this but it's been a process and I need to collect pilot data ASAP).

However, I've made some changes in line with your suggestions. For now, I've reduced my TR to 1s so that my stimuli can easily be in multiples of the TR. With the new options, I've been able to assign unique stimulus timing to my trial types (R1, N1 = 3s, R2,N2 = 4s) and my catch trials (CatchR1,N1 = 1s, CatchR2,N2 = 2s). It seems as though I should easily be able to then set my rest periods to be TR_locked, with the major caveat that this is not ideal timing. However, I've been unsuccessful in getting my rest periods to actually reflect this - they're always set to non-TR-locked values when I view the output.

I currently have my run time set to 2.5*total task time to allow for a significant amount of rest and am allowing for any extra post-stimulus time to be allocated to rest, but otherwise I have no justification for this specific length. My minimum rest is set at 1 with mean and max not specified (previously I had been getting warnings that these were set too low when I tried to give pre-specified values). I've also tried setting rest using t_gran instead of TR although my understanding is that t_gran is obsolete when TR is specified as this value is used to determine t_gran.

Do you have any suggestions for what I may be doing wrong? I did read that many of the older options are incompatible with the advanced options, but from the help document it seemed as though this should be possible.


make_random_timing.py -num_runs 4 -run_time 390 \
-pre_stim_rest 10 -post_stim_rest 10 \
-rand_post_stim_rest yes \
-add_timing_class stima 3 \
-add_timing_class stimb 4 \
-add_timing_class stimc 1 \
-add_timing_class stimd 2 \
-add_timing_class rest 1 -1 -1 -tr 1 -tr_locked \
-add_stim_class R_1 8 stima rest \
-add_stim_class N_1 8 stima rest \
-add_stim_class R_2 8 stimb rest \
-add_stim_class N_2 8 stimb rest \
-add_stim_class Catch_R_1 4 stimc rest \
-add_stim_class Catch_N_1 4 stimc rest \
-add_stim_class Catch_R_2 4 stimd rest \
-add_stim_class Catch_N_2 4 stimd rest \
-write_event_list events.RANTI \
-show_timing_stats \
-save_3dd_cmd cmd.3dd.RANTI.txt \
-make_3dd_contrasts \
-seed 31415 -prefix stimes.RANTI