Why would you assume that matter produces pterbation to the R-S vacuum metric? Remember assumptions make an ASS out of U and ME.
I also have a problem with your idea of gravitational forces between point particles on the brains in a Randall-Sundrum two brain model. I think in this type of medium you need to use proper and precise terminology and spelling, we are all scientists here so lets call a spade a spade and point particles on the brain "axons". "Brain bending"? more like "Crazy"!
Also I think we can be relatively sure that any gravitation between brain particles will be small. Real small. Have you ever heard of "G = (M1 * M2)/d^2? It is called highschool open a book you retard.
I believe you mean "$S^1/Y_2$ symmetry"