Dear Daniel
Assuming it's DCM for fMRI, the self-connections are the level of self-inhibition, where more positive = more self-inhibition, more negative = less self-inhibition (i.e., disinhibition). PEB is simply a GLM or ANOVA on those parameters, so in your example, positive parameters for the covariate indicates more self-inhibition for the drug than placebo, and negative parameters indicate more self-inhibition for the placebo than the drug.
Best
Peter
On 30/09/2020, 23:06, "SPM (Statistical Parametric Mapping) on behalf of Daniel Martins" <[log in to unmask] on behalf of [log in to unmask]> wrote:
Dear DCM community
I am having difficulties in interpreting changes in DCM intrinsic self connection parameters in terms of self-inhibition. Let's assume that in my PEB i used a covariate to look for treatment effects, coded -1 for placebo and 1 for drug. Finding a negative parameter in this case, implies an increase or a decrease in self inhibitory tone? In the extrinsic connections, this is straightforward but for self-connections I am struggling to make an interpretation with certainty.
Thanks in advance
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