Aging-Related Differences in the Resolution of Ambiguity from Case Marker Deletions in a Verb-Final Language

Abstract

Objectives: This study investigated how age differences impact the resolution of syntactic ambiguities arising through the manipulation of verb voice types and the number of noun phrases (NPs) in stimuli sets. The stimuli consisted of ambiguous sentences that we created by deleting case markers in Korean sentences. We examined resolution strategies from the viewpoint of the nominative-initial preference. Methods: A total of 105 Korean-speaking individuals participated in the study (young adults 49, old adults 56). We manipulated the number of NPs (1 vs. 2) and the verb voice types (active vs. passive) in morphologically ambiguous sentences with NPs that had no case markers. We administered a picture-selection task to examine this nominative-initial preference. Results: We found significant differences in the use of the nominative-initial strategy between the two age groups. Younger adults consistently demonstrated a preference for the nominative-initial strategy across conditions. In contrast, elderly adults presented less preference for the nominative-initial strategy than the younger adults. Conclusion: These findings indicate that elderly adults performed significantly differently in the engagement of the more frequently used syntactic template-based strategy (nominative-initial strategy) than younger adults when resolving syntactic ambiguity. The differences between the age groups in ambiguity resolution strategy may explain aging-related declines in sentence comprehension abilities. Sentence comprehension is a complex process in which listenersand readers absorb linguistic information at multiple levels, including but not limited to syntactic and semantic units. When linguistic information is insufficient in a given context, people encounter ambiguity (Bader, 1997). In auditory sentence comprehension, listeners must employ various strategies to resolve ambiguities and understand the sentences they hear. Psycholinguistic researchers have long sought to identify the underlying reasons for individual differences in ambiguity resolution. The linguistic sources that induce syntactic ambiguities may vary across the languag-es. Some languages, such as English, that focus on word order in syntactic resolution display ambiguities in garden-path sentences that prevent listeners from performing linear processing for comprehension. However, languages such as Korean that has a relative freedom in the word order have different sources from English when processing syntactically ambiguous sentences.As shown in (A in Box 1), Korean is a verb-final language that overtly case marks noun phrases (NPs) (Sohn, 2001). These NPs can be scrambled as long as predicates are placed at the end of sentences (B in Box 1). Case is not overtly marked in English-type

Eye-movement reveals word order effects on comparative sentences in older adults using a verb-final language

“…Korean is a predicate-final language with a typical word order of subject-object-verb (SOV). One of the linguistic characteristics of Korean is its relatively flexible word order, due to its case markers which carry linguistic information for syntactic parsing ( Comrie, 1989 ; Sung et al, 2019 ). In comparative sentences, these case markers allow scrambling as long as the two NPs precede an AdjP, while preserving the meaning ( Yeom, 2016 ).…”