The advisory boards of the several state hospitals are advisory to the State Department of State Hospitals and the Legislature with power of visitation and advice with respect to the conduct of the hospitals and coordination with community mental health programs. 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 chairman. They shall meet at least once every three months and at such other times as they are called by the chairman, by the medical director, by the head of the department or a majority of the board. No expenses shall be allowed except in connection with meetings so held.