A model is made of psychological processes as a homeostatic adaptive control system describable by momentary states with transformations occurring between states. According to the model a major determinant of psychophysiological state and state of consciousness is the nature of the information transmitted between subsystems. Control of state is therefore achieved through control of the information transmitted between subsystems.
Gaarder K, Chase C. Control of States of ConsciousnessI. Attainment Through Control of Psychophysiological Variables. Arch Gen Psychiatry. 1971;25(5):429-435. doi:10.1001/archpsyc.1971.01750170045008