The development of language constitutes a major achievement and landmark in the general development of the young child.1 Since language depends upon the structural, psychomotor as well as the intellectual and emotional integrity of the organism, the study of language development can serve as an additional differential diagnostic and prognostic tool in determining areas of dysfunction which may not otherwise be discernible at an early age.
Investigation into the causes of delayed or inadequate communication in the young child facilitates diagnosis since compensatory mechanisms and emotional overlays have often not yet developed. It also ensures habilitative measures at a time when they are most effective, that is, between 3 and 4 years of age. During this time, when language development is most directly dependent on sense perception, absent or defective functions of perception—body image, spatial orientation, and figure ground discrimination leading to symbol behavior-may be developed by training. This