SEAT DEVICE FOR VEHICLE AND CONTROL METHOD FOR SEAT DEVICE FOR VEHICLE

Provided is a vehicle seat device that includes a headrest to support a head of an occupant seated on a vehicle seat. The vehicle seat device includes a rest operation adjustment mechanism provided on the headrest and to restrict or allow movement of the head of the occupant seated on the vehicle seat and a controller that controls the rest operation adjustment mechanism to allow the movement of the head of the occupant when a frequency of a vibration in a width direction of a vehicle is equal to or larger than a predetermined value.