Age-related differences in ERP components associated with processing homonyms depending on the context type of adnominal and verb phrases

Abstract

Objectives: The purpose of this study was to investigate age-related differences in Event-Related Potentials (ERP) components associated with processing of homonyms according to the context type of adnominal and verb phrases. Methods: A total of 42 participants (young 22, elderly 20) participated in the study. The stimuli were Korean sentences containing homonyms. Each sentence had adnominal and verb phrase context, and each context was biased toward dominant meaning or subdominant meaning. The target sentences were classified into four conditions depending on these contexts. Results: The elderly group showed significantly lower accuracy and slower reaction time than the younger group. ERP results revealed that the N400 and P600 components emerged in the dominant meaning of the adnominal phrase context for the younger group, whereas the sustained negativity component emerged in the subdominant meaning of the adnominal phrase context. In contrast, the elderly group demonstrated delayed negativity in both the dominant and subdominant meanings of the adnominal phrase context. Conclusion: N400 and P600 components in the younger group reflect difficulties in integrating lexical expectancy and monitoring process which trigger reanalysis when integration fails. Sustained negativity in the subdominant meaning of the adnominal phrase context from the young group seems to be associated with additional processing costs of inhibiting the dominant meaning of homonyms, which is more frequently activated than the subdominant meaning. The delayed negativity in the elderly group can likely be attributed to slowed cognitive-linguistic processing in interpreting the homonyms. © 2018 Korean Academy of Speech-Language Pathology and Audiology.