He was awarded the Nobel Prize for Medicine in 1914 for his work on the physiology and pathology of the vestibular apparatus of the inner ear, which helps to provide balance. Bárány theorized that the fluid in the inner ear was sinking when it was cool and rising when it was warm, and thus the direction of flow of the fluid was providing the signal to the vestibular organ. He followed up on this observation with a series of experiments on what he called the caloric reaction. The research resulting from his observations made surgical treatment of vestibular organ diseases possible. Bárány also investigated other aspects of equilibrium control, including the function of the cerebellum (region of the brain important for the integration of sensory perception).