hi all (especially Rick)

I am helping out someone here at Sussex with using make_random_timing.py to generate a jittered rapid event-related design for data that will then be fed into an MVPA analysis. there are 30 stimuli, which currently are to be presented 6 times each in about 16 minutes total. 3dDeconvolve -nodata does not complain about matrix problems.

here is the output of make_random_timing for the winning iteration:


++ total time = 980.0, (stim = 522.0, rest = 458.0)
init rest = 4.0, end rest = 12.0, min rest = 1.4
total ISI = 442.0, rand ISI = 147.7
rand ISI rest time = 1476 intervals of 0.100 seconds

ISI statistics :
data min mean max stdev
----------- ------- ------- ------- -------
pre-rest 5.100 5.100 5.100 0.000
post-rest 17.500 17.500 17.500 0.000
run #0 ISI 1.450 2.155 6.450 0.909
all runs ISI 1.450 2.155 6.450 0.909

This looks ok to me, but I noticed about half of the ITIs are around 2, and the max is 6ish. I am wondering if this is enough jitter, or if it would be worth adding a few minutes to the length of the task to get more ITI time. I know there is no absolute answer to this question, I just want to be as helpful as I can for my colleagues.

More generally, I guess I was just hoping to get some feedback as to whether this design is ok to run (e.g., balance of stimulus time to ISI time).

thanks in advance

James



Edited 1 time(s). Last edit at 02/02/2016 11:06AM by jkeidel.