Early language processing efficiency predicts later receptive vocabulary outcomes in children born preterm

As rates of prematurity continue to rise, identifying which preterm children are at increased risk for learning disabilities is a public health imperative. Identifying continuities between early and later skills in this vulnerable population can also illuminate fundamental neuropsychological processes that support learning in all children. At 18 months adjusted age, we used socioeconomic status (SES), medical variables, parent-reported vocabulary, scores on the Bayley Scales of Infant and Toddler Development (third edition) language composite, and children's lexical processing speed in the looking-while-listening (LWL) task as predictor variables in a sample of 30 preterm children. Receptive vocabulary as measured by the Peabody Picture Vocabulary Test (fourth edition) at 36 months was the outcome. Receptive vocabulary was correlated with SES, but uncorrelated with degree of prematurity or a composite of medical risk. Importantly, lexical processing speed was the strongest predictor of receptive vocabulary (r = -.81), accounting for 30% unique variance. Individual differences in lexical processing efficiency may be able to serve as a marker for information processing skills that are critical for language learning.