Claude Bernard (mid-19C) Studied homeostatic sub-systems in the physiology of living organisms. Homeostatis is the tendency of biological systems to maintain a state of equilibrium - as in hormone and pH levels, O_2/CO_2 and nutrients/waste concentration, ion concentration in body fluids, volume and pressure of extracellular fluids, body temperature, etc.. (Discovered as systems of internal balance in individual organisms, later also seen in ecological patterns of balance in a community of organisms.) Mechanisms of homeostatis are structural, functional (bio) and behavioural (in psychology, goal-directed behaviour - ``drive'' or ``motivation'').
See 1940s Heinz von Foerster and Kenneth Craik.
Norbert Weiner in 1948 who wrote Cybernetics: or Control and Communication in the Animal and the Machine coined the term Cybernetics for the concept of natural and artificial organisms steering themselve using feedback; he designed self-steering anti-aircraft firing system using radar feedback.
In 1945 with von Neumann and an interdisciplinary group aimed to integrate study of the brain with engineering work on artificaial systems.
Quote from Norbert Wiener (1961): ``Information is information, not matter or energy. No materialism which does not admit this can survive at the present day.''