Developmental Change in the Integration of Information During Online Sentence Comprehension. Evidence From Eye-Tracking and Event-Related-Potentials

Abstract

Understanding the moment-to-moment process by which children transform an unfolding stream of sounds into a communicated message can provide much needed insight into the architecture of the language system and the source of developmental change in language comprehension. In this dissertation, we use both eye-tracking and event-related potentials to get insight into how various sources of information constrain interpretation as a sentence unfolds. In Paper 1, we use the visual world eye-tracking paradigm to study comprehension of garden-path sentences. By comparing monolingual and bilingual children in this task, we evaluate the roles that linguistic and cognitive development play in both the selection and revision of syntactic predictions. Using both group comparisons and correlational approaches, we show that improvement in the use of top-down cues during online comprehension reflects increased language experience. In Paper 2, we use the test case of negation to evaluate integration of semantic structure during lexical access. Using the N400 response, we test whether adults and children could use negation to update lexical predictions when negation occurs as a response to a polar question. In the current paradigm, we find that neither adults nor children show online use of negation when the negated proposition is unpredictable. However, we propose that future work should be conducted to see whether incorporation of logical semantics may improve in a more reliable discourse context. Finally, in Paper 3 we use a new method of looking at ERPs during a natural story-listening task. We find that in a rich, highly predictable discourse, children but not adults show N400 responses that reflect the frequency of the words they hear. However, beyond the effects of frequency or semantic relatedness, both child and adult responses are sensitive to word predictability. Our findings suggest that during naturalistic listening, both adults and children use top-down constraints from the semantic/syntactic/pragmatic context to access upcoming words. However, in children, lower level information continues to play a more central role. We argue that studies using event related potentials, and natural listening tasks more particularly, offer an exciting opportunity to expand the contexts in which online language comprehension has been investigated.