It is said that there is a mutual relation among the functions of the cerebral cortex, the central nervous system and physical activity. And it is true that the functions of hands and fingers of mentally retarded children has the tendency of lowering generally.
We have observed some kinds of physical activity of preschool children of various ages to investigate concrete aspects of such a mutual relation.
One of the results indicates that controling movements of the five fingers independently and hopping on one foot are difficult for children under CA 3:5. But they are possible for all children of CA 4:5 and upward.
We haye discussed that there is necessity to consider the relation between the development of the brain and physical activity in curricula for preschool children.