Hi everyone,
I am having some problems with Bayesian model
selection for DCM in SPM8. I have been using the random and fixed
effects analysis, but the results have been unusual. Each model
selected for the random effects analysis appears to have a very low log
evidence in the fixed effects results, so much so that the model is not
even reflected in the graphical representation. A possible problem is
that some models may have been estimated in SPM5
and some in SPM8, though all models have been specified in SPM8. Could
this
affect the BMS result? Is there a way to check to see which models
were estimated in SPM8 versus 5? I have tested the results out using
different groups of models to see if the same pattern arises,
particularly by grouping those that were definitely estimated in one
version of SPM, and because it does, it seems as if there may be an
additional technical issue. Does anyone have any suggestions on how I
could approach this problem?
Thanks for your help.
Sunali