ABSTRACT
This chapter is concerned with the developmental changes which occur in the child's interactions with his environment; changes which denote an increasing ability to comprehend events and to function effectively within the environment. The sensory organs of the body consist of highly specialised cells which, when stimulated by a specific external event, transmit electrical impulses to the brain. When light falls upon the retina of the eye it will cause a pattern of cells to be activated. It has already been noted that information received by the sense organs needs to be processed and classified in terms of previous experiences if it is to be recognised. Yet it is very probable that the phenomenon being perceived may never have been experienced in quite the same way before. Active engagement in dealing with the environment is thought to be fundamental to an optimal development of perceptual and cognitive processes.
