Hello Dr. Donald McLaren,

I am having some trouble with an error I received while computing gPPI for two amygdala VOIs. 

The right amygdala VOI worked well, using a mask from pickatlas. 

However, when I try to compute gPPI for the left amygdala I get the following errors for 2 participants. 

1)
Index exceeds matrix dimensions.

Error in timeseries_extract (line 369)
Error in PPPI (line 461)

2)
Error using svd
Input to SVD must not contain NaN or Inf.

Error in timeseries_extract (line 378)
Error in PPPI (line 461)

I checked the mask.mat files created by the first level analysis, and they look the same as those created by other participants in which gPPI was successful. 

I also opened the omnibus F -test con-images created by gPPI, and set p=1. There appears to be no missing information that would result from a faulty mask.mat file created in the first level.

When I did an ROI analysis for the amygdala VOI using the omnibus F test, I got a cluster size of 221 with Z=2.71 for the participant I got an error for (another participant I got an error for had a similar cluster size but with a Z=4.21). Then for other participants, which ran properly, the cluster size was 220 with Zs of around 3.71

Any ideas would be much appreciated! Thank you for your time!