"It had already occurred earlier to Hess that in the experiments on diencephalic stimulation modes of behaviour were occasionally evident in the experimental animal, which suggested a manifestation of psychic powers. Thus was the theme of The Biological Aspect of Psychology (1962) established; this was taken up, after the fundamental findings on stimulation or extirpation at defined sites in the diencephalon had previously been described in an atlas (1956).
Out of this work on the integration of the experimental material in question concerning psychologically motivated expressions of the functional organization of the brain, among other things a contribution has been brought about towards bridging the gap which, until then, had yawned between physiology and psychiatry. At the same time in the monograph where his findings were summarized, the physiological foundations of the clinically important study of psychosomatic phenomena were dealt with, and the understanding of the mode of action of the so-called psychotropic drugs was advanced. Also, certain guiding principles for a closer contact between the investigation of behaviour and the type-specific organization of the central nervous system were included."
https://www.nobelprize.org/prizes/medicine/1949/hess/biographical/