Hi, I am having a related problem: I don't want 0-events that last longer than a normal trial (2 sec) and lead to the fact that the number of a TR (2sec) in the run is not equal to the number of trials. Setting --tnullmax 2 produces an error:

ERROR: could not enforce tNullMax (ntries=100000) ERROR: syntheszing schedule

Does it make sense to use optseq with this many restrictions at all?

My command: --ntp 200 --tr 2 --psdwin 0 20 2 --ev singles 2 30 --ev pairs 2 30 --ev unquads 2 30 --ev orquads 2 30 --ev news 2 30 -- tnullmax 2 --nkeep 4 --o exp --nsearch 10000 Thanks, Kathrin

On Oct 20, 2009, at 12:09 PM, 杨宏宇 wrote:

Hi list,

I am using optseq2 to design my fMRI study. These are my scripts:

optseq2 --ntp 500 --tr 2 --psdwin 0 40 1 --ev star 12 9 --ev star 13 8 --ev star 14 8 --ev diamond 12 9 --ev diamond 13 8 --ev diamond 14 8 --tnullmin 5 --tnullmax 7 --nkeep 3 --o ex.event12.13.14s -- nsearch 5000

I have 2 events, which last for 12,13, and 14s. I found that the schedule documents I got had many null events more than 7s, however, I have set the maximam as 7s. In the sum logfile, I found that my script was recorded correctly, so could you please tell me the reason, and how to solve the problem?

Many thanks, Hongyu Division on Addiction, Psychiatry Department, UT Southwestern Medical Center

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I think this is partially a bug in optseq and partially a problem with your design. You have a total amount of stimulation time = 12*9+13*8+14*8+12*9+13*8+14*8 = 648 sec. Your run lasts 500*2 = 1000 sec, so the total amount of fixation time is 1000-648 = 352 sec. You have 8*4+9*2 = 50 stimuli, so the average time between stimuli (ie, average null) will be 352/50 = 7.04s. Yet you have constrained optseq to give you nulls between 5 and 7 sec. You need to relax this constraint or reduce the total number of time points.

doug

杨宏宇 wrote:

Hi list,

I am using optseq2 to design my fMRI study. These are my scripts:

optseq2 --ntp 500 --tr 2 --psdwin 0 40 1 --ev star 12 9 --ev star 13 8 --ev star 14 8 --ev diamond 12 9 --ev diamond 13 8 --ev diamond 14 8 --tnullmin 5 --tnullmax 7 --nkeep 3 --o ex.event12.13.14s --nsearch 5000

I have 2 events, which last for 12,13, and 14s. I found that the schedule documents I got had many null events more than 7s, however, I have set the maximam as 7s. In the sum logfile, I found that my script was recorded correctly, so could you please tell me the reason, and how to solve the problem?

Many thanks, Hongyu Division on Addiction, Psychiatry Department, UT Southwestern Medical Center

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