Hello,

I am using Qdec to analyze thickness (etc) using various IVs (e.g., Verbal IQ) while controlling for cortical grey matter volume (or ICV) as a nuisance factor. With the exception of the IV Sex, every time I run the analysis it goes into an endless loop, sporadically stating that the "Matrix is Ill-conditioned". It doesn't work with discrete or continuous variables. It also happens for the other DVs, like Sulc.

Has anyone ran into this problem before? I couldn't find it on the listserv archives.

Thank you for your help,

Adam