Hi Giuseppe,

> Is 1dsvar scriptable, even if at the individual subject level only? It is quite a bit
> of work to re-enter the same specifications over and over interactively for
> every subject, if you have a large group.

I haven't thought about scripting with 3dSVAR. You could save all the command lines for one subject into a text file, then make multiple copies of the content, and replace those lines that are subject specific. Then run the big file in a batch mode.

I have also encountered the numerical issue you mentioned. My guess is that it has something to do the infamous problem with SEM/SVAR when a nonrecursive network (a few paths forming a loop) is hypothesized. In your case,

R.IFG R.TPJ R.Hipp vPMC
R.IFG 0 NA 0 0
R.TPJ NA 0 0 NA
R.Hipp 0 0 0 NA
vPMC 0 NA 0 0

there are two feedback paths that are nonrecursive:

R.TPJ --> R.IFG --> R.TPJ
vPMC --> R.TPJ --> vPMC

I have tried so far one workaround solution, but the result was not that great.

> Would it be possible to compare the fit for different instantaneous effects matrices?

Yes, that's definitely a can-do. I just need to implement it at some point. Do you need it soon?

Gang