Originally published in 1977, the objective of this book was to examine the mechanisms by which the multiple factors or determinants - homeostatic deficits, hormonal influences, circadian rhythms, experiential and cognitive factors - become translated by the central nervous system into thermoregulatory, feeding, sexual, aggressive, and other behaviours. A conceptual framework has been used that reflects relevant contributions from biology, regulatory physiology, physiological psychology, and other neuroscience disciplines. The final chapter deals with difficulties in brain-behaviour research in relation to experimental strategies and with crucial problems for future investigation.