Examined the human infant literature on supplemental stimulation to delineate a course of intervention based on the ontogeny of the nervous system and the impact that systematic stimulation may have on behavioral organization in the premature infant. Effects of vestibular, tactile/kinesthetic, auditory, and oral stimulation are discussed with respect to their similarity to the intra- or extra-uterine environment. Long-standing theoretical and methodological problems are discussed, and a "sequential multimodal treatment model" is introduced.