Could you please give me some specific details about what exactly you need your two-back task to do in DirectRT? That is, what should a typical trial of this task look like and what do you need your participants to do.
What specifically are you having trouble programming DirectRT to do?
Please also tell me the full version number (i.e., 20xx.x.xxx) of your copy of DirectRT. You can find it by opening DirectRT and selecting Help>About DirectRT from the main menu bar.
Jason Reed
Empirisoft Software Support Specialist