Age-Related Differences in Korean Word Recognition Associated with Phonological Rules and Word Frequency: An Event-Related Potential (ERP) Study

Abstract

Objectives: The purpose of this study was to investigate age-related differences according to frequency of words and use of phonological rules in the Korean word recognition process between younger and elderly groups through Event-Related Potentials (ERP) analysis. Methods: A total of 35 participants participated in this experiment. They were asked to judge whether the pronunciation of visual words was identical to the corresponding auditory words. Behavioral data and electrophysiological data were collected. Results: Behavioral results revealed that the elderly group showed significantly lower accuracy and longer response time than the younger group. ERP analysis showed that there was no significant difference between the two groups in the 150-300 ms range. However, for the younger group, the N400 component was observed in the 300-500 ms range regardless of word frequency when the phonological rule was not applied and was more apparent under the low word frequency condition. The topographic patterns of the grand average ERP waveforms for the elderly group showed that the N400 component appeared only under high word frequency when the phonological rule was not applied. However, when the phonological rule was applied, the N400 component was observed only under the condition of low word frequency. Conclusion: Differences in the pattern of applying phonological rules associated with word frequency were found between groups. The current study indicates that word frequency and aging may affect the ability to apply phonological rules. The result of age-related differences in ERP analysis reflects a decline in the simultaneous neural processing of phonological and semantic information. © 2021 Korean Academy of Speech-Language Pathology and Audiology