The advisory boards of the several state developmental centers are advisory to the State Department of Developmental Services and the Legislature with power of visitation and advice with respect to the conduct of the developmental centers and coordination with community mental health programs or regional programs for persons with developmental disabilities. The members of the boards shall serve without compensation other than necessary expenses incurred in the performance of duty. They shall organize and elect a chairperson. They shall meet at least once every three months and at any other times they are called by the chairperson, by the medical director, by the head of the department, or by a majority of the board. No expenses shall be allowed except in connection with meetings so held. The advisory board or boards of each developmental center or state hospital and developmental center may make a written report on its activities.