Then, wishing to approach the more strictly experimental aspects of life sciences, and in particular the new neurosciences, he joined, as an epistemologist, the Department of Experimental Medicine of the Faculty of Medicine of Lyon headed by Michel Jouvet, to study the development of research on REM sleep and dreams, mainly from the philosophical angle of ""psychophysiological parallelism"", which involved all disciplines of neuroscience, and from that of functional hypotheses, making REM sleep play a functional role in the individuation of the brain.