A seat assembly includes a seat having a seat base and a seat back, an electronic control unit (ECU), a sensor assembly, and/or a response assembly. The ECU may be configured to determine via the sensor assembly whether an occupant disposed in the seat is in a first state, a second state, or a third state. The ECU may be configured to control the response assembly to change the state of said occupant from the first state to the second state and from the third state to the second state. The ECU may be configured to determine at least one of a breathing rate, a heart rate, and a heart rate variability of said occupant via the sensor assembly.
