Looking beyond the overall effectiveness of sensory stimulation, this study aimed to identify specific aspects of infant behavior most responsive to early stimulation. Subjects were 65 premature infants with a birth weight of less than 5 pounds, 8 ounces and a gestational age under 37 weeks. Experimental group members had completed a multimodal sensory stimulation program during their hospitalization; control subjects had not. Mental and Motor Scales of the Bayley Scales of Infant Development were employed in each infant's assessment. Discriminant analysis identified 22 items from these scales as predictors of membership in either the stimulated or unstimulated group; 18 items were from the Mental Scale, and four were from the Motor Scale. In general, the stimulated group had scores on both scales higher than those of the unstimulated group. Results also indicated that for some items there may be an inverse relationship between pass-fail scores and the child's chronological age, thus suggesting that the standard scoring procedure may be inappropriate. (RH)