ABSTRACT
An important belief shared by the contributors to this volume is that our understanding of learning can profit by studying its ontogeny in altricial animals such as mice, rats, cats, and dogs. As noted by many writers (Campbell & Spear, 1972; Campbell & Coulter, 1976; Kenny & Blass, 1977; Rosenblatt, 1971; 1972), altricial animals are attractive subjects for this purpose because at birth they are quite helpless; their nervous systems are markedly underdeveloped, and their sensory systems and behavioral repertoire are correspondingly primitive. Such animals, however, also mature in a relatively short time period. For example, by about 4 weeks of age the central nervous system of the rat in many ways approximates that of the adult. its sensory systems are functioning, and its behavioral repertoire is quite rich. Consequently by studying such animals at various ages, one might hope to discover important changes in their learning capabilities and possibly even identify neurological and neurochemical changes that are of functional significance to the learning processes.
