Dear Alfonso and all,

I am trying to find the dynamic functional connectivity of 22 subjects. Each subject has 2 sessions of 'rest', hence I have given the two sessions as two conditions rest1 and rest2. I am interested in finding the dynamic functional connectivity of the subjects in both conditions separately. But when I run the dynamic functional connectivity analysis, the dynamic decomposition step first gives me warnings that the matrix is singular to working precision or badly scaled and RCOND is NaN, and then ends in an error that NaN or Inf cannot be used.

The dynamic FC worked perfectly with another dataset which had 11 subjects and a single rest session. Hence I am guessing that the problem is with the design which specifies two different conditions. I read on one of the previous posts that the PPI code in CONN doesn't have an option to find the connectivity independently in each condition, and the code needs to be tweaked a little bit. I am trying to understand the code to be able to achieve this, and I would be grateful if you could offer any help on this. I would also like to know if it is possible to manually compute the dynamic decomposition and give it as a second level covariate for the rest of the computation by CONN, or if there is any other work around to achieve this.

Thanks a lot
Shukti