Aging-related differences in the resolution of ambiguity from case marker deletions in a Verb-Final Language

Abstract

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. © 2019 Korean Academy of Speech-Language Pathology and Audiology.