Parents’ Gestural but not Verbal Input Associates with Word Comprehension in Pre- and Full-Term Infants

• In Event: Lexical Development: environment and mechanisms

Abstract

The interaction between parent and child occurs is multimodal (Tamis-LeMonda et al., 2013). Parental input involves spoken, gestural input, and exaggerated actions. Parents frequently coordinate verbal and gestural cues, such as labeling, while pointing to objects. Parents' verbal (Hurtado et al., 2008) and gestural (Iverson et al., 1999) input support children’s vocabulary development. Since pre- and post-natal factors can influence the interaction between parent and child, the input can differ in infants with high risks (Korja et al., 2010). Preterm children (PT, born before 37 weeks of gestation) show delays in language development compared to their full-term peers (FT). For example, PT children’s receptive vocabularies lag behind their FT peers in the early years (Barre et al., 2011; Sansavini et al., 2014). Despite the emphasis on biological factors in influencing PT children’s development, less is known about the role of parental input. Here, we investigated the concurrent relationship between parental language input (type and token) and vocabulary comprehension in PT and FT infants.
We recruited 78 infants (Mage=13.70 months, SD=1.42, 41 PT). Parental input was coded in terms of the number of utterances and total gestures from a 10-minute play session. The total gestures were then divided by the total utterances. Parents’ gestures were classified as deictic (e.g., pointing to a ball to indicate a ball), iconic (e.g., depicting a bird by flapping arms), beat (e.g., flicking hands to highlight speech), conventional (e.g., raising thumb to mean okay), object manipulation (i.e., counting by moving abacus). Each gesture category was divided by the total gestures. To assess children's word comprehension, we asked parents to fill the Turkish version of MacArthur-Bates Communicative Development Inventory (Aksu-Koç et al., 2019).
Parental total utterances spoken to infants were lower for PT than FT group, p=.036, yet it did not relate to children’s total vocabulary comprehension. Although gesture rates were similar between PT and FT parents, p=.796, FT parents produced more deictic gestures than PT parents (p=.002), and PT parents used more object manipulation than FT parents (p=.001). Hierarchical linear regression analysis demonstrated that deictics were associated with word comprehension of infants (β=.351, p=.001), after controlling for infant age, neonatal status, and total utterances, R2= 40.10%, F(4, 68)=11.38, p<.001. There was not a significant interaction between deictic gestures and neonatal status on word comprehension, p=.463. Additionally, after controlling for age, neonatal status, and total utterances, object manipulation was negatively related to word comprehension, (β=.-319, p=.004), R2=38.50% F(4, 68)=10.63, p<.001. No significant interaction was found between object manipulation and neonatal status on word comprehension, p=.506.
These findings emphasized the role of multimodal input on word comprehension for PT and FT infants. Beyond neonatal status, deictic gestural input was positively related to infants’ concurrent vocabulary comprehension; yet, object manipulation was negatively associated with word comprehension. Supporting earlier findings with FT infants, at this early stage of word learning, deictic gestural input as a socio-cognitive tool can be a better predictor of infants’ vocabulary learning. Additionally, this relationship also remains for PT infants.

Authors

• Işıl Doğan, Koç Üniversitesi
  Presenting Author

• Erim Kızıldere, University of California - Davis
  Non-Presenting Author

• Mert Kobaş, Koç University
  Non-Presenting Author

• Asli Aktan-Erciyes
  Non-Presenting Author

• Ece Demir-Lira, University of Iowa
  Non-Presenting Author

• İpek Akman
  Non-Presenting Author

• Tilbe Göksun, Koç University
  Non-Presenting Author