Anton Gerbrand: Gaze onto language development: Exploring the Links Between Early Statistical Learning, Word Recognition, and Vocabulary Growth in Infancy and Beyond

Abstract

This thesis aimed to investigate early mechanisms related to language development, with a focus on statistical learning (SL), word recognition, and their influence on later vocabulary. The thesis thus focused on three main goals; first, to explore the role of SL in early language development; second, to determine whether early word recognition tasks can capture individual differences in vocabulary during infancy; and third, to examine how cardinal recognition relates to abstract number word learning in early childhood. Study I employed eye-tracking tasks that assessed learning of associations, sequential patterns, and probabilities in visual and visual-auditory domains. The results showed that associative learning at 10 months predicted expressive vocabulary at 18 months, and sequence learning at both 10 and 18 months predicted receptive and expressive vocabulary at 18 months. However, general probability processing did not show a significant connection to later vocabulary. These findings suggest that broader learning abilities, such as associative and sequence learning, play a role in language development. Study II investigated the effectiveness of eye-tracking paradigms in capturing individual differences in word recognition in infancy and how these relate to vocabulary in toddlerhood. Results indicated that infant’s ability to look at the correct referent of a label was not stable during infancy but became more stable and predictive of vocabulary in toddlerhood. Additionally, infants’ ability to respond to matching stimuli at 11.5 months was linked to both receptive and expressive vocabulary up to 24 months. Study III examined how cardinal recognition contributes to learning abstract number concepts in children aged 2-4. Results showed that subset knowers (children who know some but not all number words) could identify all small numbers (1-4), suggesting that an approximate understanding emerges before an exact understanding of numbers. However, future research is needed to clarify how this ability develops. Together, these studies suggest that both SL and early word recognition are involved in vocabulary development, and that these abilities may evolve and interact over time, highlighting the complexity of language acquisition. Furthermore, word recognition appears to aid in the learning of both concrete and abstract words as development progresses.