Maternal object naming is less adapted to preterm infants' than to term infants' word mapping

Term infants learn word-object relations in their first year during multisensory interactions with caregivers. Although preterm infants often experience language delays, little is known about how caregivers contribute to their early word-object learning. The present longitudinal study compared maternal naming and word learning in these infant groups.

Forty moderately preterm and 40 term infants participated at 6-9 and 12 months with their mothers. At each visit, mothers named two novel objects during play, and infants' learning was assessed using dynamic displays of the familiar and novel (mismatched) word-object relations. Infants' general cognitive, language, and motoric abilities were evaluated. Maternal multisensory naming was coded for synchrony between the target words and object motions and other naming styles.

During play, although overall maternal naming-style was similar across infant groups within visits, naming frequency increased to term but not preterm infants, from visit 1 to 2. On the test at visit 1, although the term infants' looked equally to novel and familiar word-object relations, their looking to the novel relations correlated positively with maternal synchrony use but inversely with naming frequency. At visit 2, term infants looked longer to the novel relations. In contrast, preterm infants showed no looking preference at either visit. Neither was their word-object learning correlated with maternal naming. Their cognition, language, and motor scores were attenuated when compared to term infants on the Bayley-III but not their MCDI vocabulary.

Less adaptive maternal naming and delayed word mapping in moderately preterm infants underscore a critical need for multisensory language intervention prior to first-word onset to alleviate its cascading effects on later language.