I count it an honour to be able to represent my Czechoslovak colleagues at this very stimulating conference on the development of cognitive processes and to inform you of some results of our research, carried out in the Institute for Care of Mother and Child in Prague. Since this is the first opportunity for such a wide exchange of experiences, allow me to start with several preliminary comments. In our country, there is a long tradition of particular interest in child development-it is probably not necessary to mention the famous seventeenth-century pedagogue Jan Amos Comenius-yet we still feel that little has been done to place research on child development on an exact scientific basis, particularly as far as very early development is concerned, in spite of its generally acknowledged importance. It is well known that in early infancy marked developmental changes occur in various physiological or psychical functions and that optimal conditions should be established to prevent deviations unfavourable for the whole further development. This is especially true in regard to brain functions, but there is a question of whether we have sufficient criteria to estimate precisely enough the development of brain functions or the factors that influence this development. Since brain functions gradually become extremely complicated with increasing age, we have another reason to learn more about them at the very beginning of their postnatal development. In our Institute, there is close collaboration between obstetricians, pediatricians, psychologists, and ontogenetic physiologists, fully engaged in research activity. A child can be followed from birth through the whole of infancy; particularly suitable conditions have been created for studying child development from various aspects, such as, the development of homeostasis, metabolism, respiration, thermoregulation, and immunological reactivity. The development of brain functions is studied in the laboratories of higher nervous activity led by 0. Janos. From the very beginning we have been interested in both physiologic and psychologic aspects of brain func-