The lost physiology of consciousness: Ernst Gellhorn and the origins of homeostatic neuroscience.

Contemporary neuroscience often presents modern theories of consciousness as products of the cognitive revolution and computational neuroscience. Yet several neurophysiologists before and during the early cybernetic period had already developed sophisticated physiological models of conscious states grounded in bodily regulation, autonomic integration, hypothalamic function and global neural activation. Among these figures, Ernest Gellhorn (1935-2005) occupies a remarkable place. In Physiological Foundations of Neurology and Psychiatry (1953), Gellhorn proposed an integrative neurophysiological theory linking consciousness, arousal, emotion, endocrine regulation, autonomic balance, sleep, and bodily homeostasis. This article argues that Gellhorn prefigured several dimensions of contemporary consciousness research, especially embodied, affective, and homeostatic approaches. It also situates him within the broader neurophysiological framework represented at the 1953 Laurentian Symposium, where Giuseppe Moruzzi (1910-1986), Horace Winchell Magoun (1907-1991), and Denise-Albe Fessard (1916-2003) emphasized reticular activation and large-scale nervous integration. The comparison has clear limits: Gellhorn did not anticipate the anatomically defined functional networks revealed by modern neuroimaging, the information-broadcast architecture of global neuronal workspace theory, or the philosophical "hard problem" of why physiological processes are accompanied by subjective experience. Rather than claiming direct historical continuity, the study identifies structural conceptual convergences between mid-twentieth-century neurophysiology and selected current theories of consciousness.