Hi all,

I figured I would have some luck tapping expertise on using optseq2 in this mailing list. There are 8 trials times 8 conditions in an event-related design. We are using a 1-back task just to keep participants paying attention. Thus, we are not attempting to match the number of 1-back-yes and 1-back-no trials. In fact, ideally we would have exactly 1 1-back-yes trial for each of the 8 conditions. The plan would be to arrive at a paradigm schedule where, for each of the 8 conditions, there is at least 1 set of consecutive trials for that condition. In this way, if we use only 7 stimuli, then the consecutive trials can use the same item, and that would constitute the 1-back-yes event for that condition as in:

1 a1.bmp 2 b1.bmp 0 NULL 3 c1.bmp 2 b2.bmp <-- 0 NULL 2 b2.bmp <--first instance of consecutive events from same condition assigned same item to create a 1-back-yes event

The problem is that I have not discovered any means within optseq to enforce the criterion that at two consecutive events are from the same condition for all 8 conditions. The best I can do is create a large enough pool of paradigm files, and sort through them in the hopes of finding several that meet this requirement. Can optseq2 be forced to meet this requirement, either as a normal command line switch, or else through some clever condition labeling trickery?

Thanks, Chris