Frontiers in Psychology (Apr 2014)
Age-related changes in ERP components of semantic and syntactic processing in a verb final language
Abstract
Introduction Several researchers suggested that older adults performed less accurately and more slowly than younger adults on sentence comprehension tasks (DeDe et al., 2004; Kemtes & Kemper, 1997; Waters & Caplan, 2001). However, it has been controversial whether there might be age-related changes during online processing. Previous research employed a word-by-word reading or listening paradigm to measure older adults’ online sentence processing abilities. In contrast, there are few studies to qualitatively examine age-related differences in how semantic and syntactic information are processed using event-related potential (ERP). The current study investigated age-related differences in offline and online sentence processing using ERP in a verb-final language. Methods Sixteen younger adults (mean age=25.8, SD=3.1) and fifteen older adults (mean age=73.0, SD=6.0) participated in the study. Ninety target stimuli consisted of three conditions: (1) plausible, (2) syntactic violation on the second noun phrase with an irrelevant case marker (Word2), (3) semantic violation on the third word containing an irrelevant verb (Word3). Each phrase (Eojeol) was presented for 700ms using a Rapid Serial Visual Presentation paradigm with a 200ms inter-stimulus interval during the 32-ch EEG recording. Results 1. Behavioral data Accuracy and response time (RT) to the plausibility judgment served as dependent measures. Two-way mixed ANOVA revealed that the main effect for the group was significant in the accuracy, (F(1,29) = 4.53, p . However, these effects were diminished in the elderly group only at Fz (F(2, 58)=3.801, p<.05). For Word3 at 700-900ms, main effects for the condition were significant across the sites (all ps<.05). The significant two-way interaction at Fz revealed relatively greater negativity for the younger group in a semantically violated condition (F(2, 58)=6.635, p<.005). Discussion Both syntactic and semantic violations elicited negativity effects at 300-500ms time window, and the negativity effects were slightly attenuated in the elderly group. The results suggested that Korean speakers may process a syntactic component of a case marker under the semantic frame integration, eliciting the negativity effects associated with semantic violations. Elderly adults showed attenuated effects compared to the young group, indicating age-related changes emerged during real-time sentence processing.
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