Hi, I am a DCM&SPM starter in Asia. I try to reproduce C.C Chen's (2008) experiment. ps.Chen(2008) :[ Dynamic causal modelling of induced responses ] page 1307 ~ 1308 nonlinear model(p.1307) & linear model(p.1308) The data download from SPM website was prepared. (data:faces_run1.bdf & faces_run2.bdf from website, and I fixed the data already from "convert" to "averaging" ) Now I try to set DCM UI . I have a question. 1.Why F value is not negative ? Here is my setting (nonlinear model) [image: Chen 2008 DCM setting.jpg] Are there something wrong with my setting? I opened DCM <1x1 struct> from matlab , then I saw F value below. F = 4.695e+03. Thank you for your help !!!