Does the central value influence on the result of the constrained parameter on CosmoMC?

[Simony S. da Costa]

Dear all,

I am running CosmoMC for a given model incresing Neff.
Considering that I have 3 new parameters changing Neff, my prior ranges (for the new parameters) will change accordingly.
The point is that the central value I am using seems to be exactly the mean value of the posterior, no matter how I change the ranges.
Do you think this could be related with a small step?

Thank you for your help,
Simony