ERP studies of Korean language processing: word-order effects

Abstract

Abstract We investigated Korean language processing based on event-related potentials (ERPs) under congruent and incongruent conditions with semantic, syntactic, and combined errors. Fifteen participants were presented with visual stimuli consisting of 180 sentences ending in expected words (the congruent condition), 60 under the semantic condition, 60 under the syntactic condition, and 60 under the combined condition. The semantically incongruent condition was shown to elicit an N400 response, distributed in the right frontocentral region, as in semantic studies administered with Indo-European (IE) languages. The syntactically incongruent condition elicited P600 followed by N400 components but no early left-anterior negativity (ELAN) was detected, reflecting structural differences in Korean and IE languages. The doubly incongruent combined condition evoked N400 and P600 components with faster latency and higher amplitude compared to the syntactic conditions. The differences suggest that syntactic integration is influenced by semantic processing, but also that the semantic structure is independent of the syntactic context in the absence of semantic anomalies. Introduction Event-related brain potentials (ERPs) have been widely used to investigate the neurophysiological mechanisms of human language. ERP studies of language processes have indicated three main language-associated ERP components: the N400, early left-anterior negativity (ELAN) /left-anterior negativity (LAN), and P600 components (Hagoort et al., 1993; Kutas & Hillyard, 1980; Osterhout, 1994). Kutas and Hillyard (1980) presented visual sentence stimuli with unexpected or incongruent endings and found a negative peak around 400 ms, observing that N400 is an “electrophysiological marker of the ‘reprocessing’ of semantically incongruent information.