Handedness and Vocabulary…Right Out of Left Field: The Role of Handedness and Statistical Learning in Infants’ Vocabulary Development

Abstract

Infants are incredible language learners. One way we think infants are able to learn language is through statistical learning (SL) where infants track the regularities in the speech stream in both adjacent (Saffran et al., 1998) and non-adjacent dependencies (NAD) (Gomez, 2002). Infants’ SL abilities are related to their vocabulary development (Graf Estes et al., 2011). Handedness is related to language abilities in adults (Knecht et al., 2000) and vocabulary development in infants (Nelon et al., 2014). This relationship between handedness and language is thought to be driven by lateralization, where handedness is a proxy for lateralization. The current study will investigate the relationship between handedness and SL in infants’ vocabulary development. Participants will be Infants (N=60) at 15-months-old. Infants\u27 handedness will be tested with the baby handedness test (Fagard et al., 2020), which is used to assess lateralization. Infants’ SL will be tested using the head-turn preference procedure with the SL language from Gomez (2002) testing NADs. Infants’ vocabulary will be measured with the McArthur-Bates Communicative Developmental Inventories. It is predicted that lateralized infants will have better scores on the SL test. A t-test will then be used to determine if there was a significant difference in statistical learning scores for lateralized versus non-lateralized infants. Multiple regression will be used to determine how lateralization and SL predict infants’ vocabulary. This study will extend and help elucidate some of the mechanisms that may play a role in language development