Mental transitional spheres

The human being may be considered to have mental transitional spheres in which the sifting, transforming, intensifying, and inhibiting of stimuli are initiated. Stimuli essential to the development of the psychic apparatus are converted in the mental transitional spheres into a form that will enable them to exert the appropriate influence on the ego. Optimal ego development cannot take place without the proper functioning of these spheres. Thus, the mental transitional spheres are essential for the development of psychic functions and defenses.