Variations of Mixed Hodge Structure attached to the deformation theory of a Complex Variation of Hodge Structures

We construct a Mixed Hodge Structure on the local complete ring of the representation scheme at the holonomy of a VHS on a compact K\"ahler manifold and prove that the corresponding tautological representation is the holonomy of a VMHS. In order to carry out this construction we revisit the well-known work of Goldman and Millson on the deformation theory of representations of K\"ahler groups.