An ERP study of ellipsis resolution in Korean

( Park Myung-kwan ),( Chung Wonil ) 한국언어정보학회 2018 언어와 정보 Vol.22 No.1

Park, Myung-Kwan and Chung, Wonil. 2018. An ERP study of ellipsis resolution in Korean. Language and Information, 22.1, 29-56. The purpose of this paper is to investigate the prediction/integration of syntactic structure during sentence processing, employing the construction that allows a TP ellipsis or Sluicing-like interpretation in Korean. To this aim we recorded event-related potentials (ERPs) from Korean native speakers while they read ellipsis constructions where the syntactic context allows or disallows remnants/ survivors (mis)matching with their explicit/implicit correlates in terms of Case/case (postposition) particle, also reflecting voice (mis)match between the antecedent and the ellipsis clauses. The Korean speakers were able to predict clausal syntactic structure on the basis of the antecedent clause and integrate it into the ellipsis site, thereby quickly detecting voice match/mismatch, as suggested by an ERP difference between matched and mismatched remnants/survivors neighboring the ellipsis site.

Voice Mismatch Meets Neurolinguistics

Gui-Sun Moon,Sun-Woong Kim,Jeong-Ah Shin,Hae-Kyung Wee,Jong Un Park,Myung-Kwan Park,Wonil Chung 현대문법학회 2018 현대문법연구 Vol.99 No.-

Gui-Sun Moon, Sun-Woong Kim, Jeong-Ah Shin, Hae-Kyung Wee, Jong Un Park, Myung-Kwan Park, and Wonil Chung. 2018. Voice Mismatch Meets Neurolinguistics. Studies in Modern Grammar 99, 85-115. This paper aims to investigate Korean advanced L2 English learners’ strategies for ellipsis resolution during sentence processing. Ellipsis resolution is known to involve several stages of information processing from the initial step of detecting an ellipsis-licensing element by the parser to the final stage of integrating the ellipsis site with the information retrieved from the antecedent of the ellipsis site. In examining these steps, we have manipulated three factors: (i) TP vs. VP-ellipsis; (ii) two types of discourse coherence relations (resemblance(-contrast) vs. cause-effect relations); (iii) voice match vs. mismatch. We found through the ERP recordings that voice mismatch in TP ellipsis elicited N400, followed by P600, irrespective of discourse coherence relations. In contrast, voice mismatch in VP-ellipsis registered N400 only in resemblance(-contrast) relation, but not in cause-effect relation. These findings lead us to conclude that Korean advanced L2 learners of English seem to undergo the full sequence of processing stages required for ellipsis resolution.

On SWIPING in English: Failure of Agree and the Subsequent Repairs

Wonil Chung,Myung-Kwan Park 한국영어학회 2014 영어학 Vol.14 No.1

Processing Double Accusatives with Korean Dative/Causative Verbs: An ERP Study

Wonil Chung,Say Young Kim,Myung-Kwan Park 현대문법학회 2021 현대문법연구 Vol.111 No.-

This paper reports an ERP-based study concerning the limited productivity of the ACC + ACC subcategorization frame with Korean dative and causative verbs. This frame is compared to the unmarkedly productive DAT + ACC frame in the ERP experiment and the acceptability rating task. The results show that the double Accusatives with the two types of dative verbs expressing caused possession or caused motion recorded N400, followed by P600, while those with morphological causative verbs registered N400 only. Likewise, the double Accusatives with both dative and causative verbs were consistently rated as unacceptable in the acceptability task. We take the disconfirmed expectation of a certain Case morphology to act as an etiology of the N400 modulation. The reader expects to encounter a dative or causative verb after the DAT + ACC sequence, but the preceding ACC + ACC sequence is not compatible with such a verb after it, evoking N400 because Case encodes morpho-lexical information. Meanwhile, reduced P600 represents a severe disruption of semantic analysis, reflected by N400; dative verbs differ from causative verbs in that the former employ covert lexical feature for causation, but the latter a morphologically-overt morpheme. The upshot of this paper is that Case as an apparently grammatical relation-encoding morpho-syntactic marker serves as a cue for predicting the following word associated with it, and ERP responses to a failure in such a Case-related prediction are not confined to a late positivity but are also detected evoking negativity at posterior regions in the 250 ∼ 500 ms interval.

Statistical models and computational tools for predicting complex traits and diseases

Chung, Wonil Korea Genome Organization 2021 Genomics & informatics Vol.19 No.4

Predicting individual traits and diseases from genetic variants is critical to fulfilling the promise of personalized medicine. The genetic variants from genome-wide association studies (GWAS), including variants well below GWAS significance, can be aggregated into highly significant predictions across a wide range of complex traits and diseases. The recent arrival of large-sample public biobanks enables highly accurate polygenic predictions based on genetic variants across the whole genome. Various statistical methodologies and diverse computational tools have been introduced and developed to computed the polygenic risk score (PRS) more accurately. However, many researchers utilize PRS tools without a thorough understanding of the underlying model and how to specify the parameters for the best performance. It is advantageous to study the statistical models implemented in computational tools for PRS estimation and the formulas of parameters to be specified. Here, we review a variety of recent statistical methodologies and computational tools for PRS computation.

Multiple Sluicing and SWIPING Meet RT-based Experimental Syntax

Wonil Chung,Myung-Kwan Park 한국중원언어학회 2017 언어학연구 Vol.0 No.42

The main purpose of this paper to scrutinize to what extent advanced L2 learners would differ from L1 speakers in the anticipation, integration, and repair of syntactic information during sentence processing. For this purpose, we conducted two on-line self-paced reading experiments for processing multiple Sluicing (or TP ellipsis) with two PP remnants in English by both L1 speakers and L2 learners and found some interesting findings as follows. First, L1 speakers showed an early effect of processing both the first preposition pied-piped and the first SWIPING-ed (or inverted preposition) PP remnant conditions in the same way, pointing to the fact that they anticipated upcoming information (TP ellipsis), whereas the L2 learners did not. The latter result is in line with those in other works showing that L2 learners do not expect upcoming syntactic categories in the same fashion as L1 speakers do. Second, L2 speakers showed a late effect of processing both the first and the second SWIPING-ed PP conditions analogously, implying either an increase in working memory or the use of different repair tactics compared with L1 speakers.

Grid-based Gaussian process models for longitudinal genetic data

Chung, Wonil The Korean Statistical Society 2022 Communications for statistical applications and me Vol.29 No.1

Although various statistical methods have been developed to map time-dependent genetic factors, most identified genetic variants can explain only a small portion of the estimated genetic variation in longitudinal traits. Gene-gene and gene-time/environment interactions are known to be important putative sources of the missing heritability. However, mapping epistatic gene-gene interactions is extremely difficult due to the very large parameter spaces for models containing such interactions. In this paper, we develop a Gaussian process (GP) based nonparametric Bayesian variable selection method for longitudinal data. It maps multiple genetic markers without restricting to pairwise interactions. Rather than modeling each main and interaction term explicitly, the GP model measures the importance of each marker, regardless of whether it is mostly due to a main effect or some interaction effect(s), via an unspecified function. To improve the flexibility of the GP model, we propose a novel grid-based method for the within-subject dependence structure. The proposed method can accurately approximate complex covariance structures. The dimension of the covariance matrix depends only on the number of fixed grid points although each subject may have different numbers of measurements at different time points. The deviance information criterion (DIC) and the Bayesian predictive information criterion (BPIC) are proposed for selecting an optimal number of grid points. To efficiently draw posterior samples, we combine a hybrid Monte Carlo method with a partially collapsed Gibbs (PCG) sampler. We apply the proposed GP model to a mouse dataset on age-related body weight.

Bayesian analysis of longitudinal traits in the Korea Association Resource (KARE) cohort

Chung, Wonil,Hwang, Hyunji,Park, Taesung Korea Genome Organization 2022 Genomics & informatics Vol.20 No.2

Various methodologies for the genetic analysis of longitudinal data have been proposed and applied to data from large-scale genome-wide association studies (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with traits of interest and to detect SNP-time interactions. We recently proposed a grid-based Bayesian mixed model for longitudinal genetic data and showed that our Bayesian method increased the statistical power compared to the corresponding univariate method and well detected SNP-time interactions. In this paper, we further analyze longitudinal obesity-related traits such as body mass index, hip circumference, waist circumference, and waist-hip ratio from Korea Association Resource data to evaluate the proposed Bayesian method. We first conducted GWAS analyses of cross-sectional traits and combined the results of GWAS analyses through a meta-analysis based on a trajectory model and a random-effects model. We then applied our Bayesian method to a subset of SNPs selected by meta-analysis to further discover SNPs associated with traits of interest and SNP-time interactions. The proposed Bayesian method identified several novel SNPs associated with longitudinal obesity-related traits, and almost 25% of the identified SNPs had significant p-values for SNP-time interactions.

Bayesian mixed models for longitudinal genetic data: theory, concepts, and simulation studies

Chung, Wonil,Cho, Youngkwang Korea Genome Organization 2022 Genomics & informatics Vol.20 No.1

Despite the success of recent genome-wide association studies investigating longitudinal traits, a large fraction of overall heritability remains unexplained. This suggests that some of the missing heritability may be accounted for by gene-gene and gene-time/environment interactions. In this paper, we develop a Bayesian variable selection method for longitudinal genetic data based on mixed models. The method jointly models the main effects and interactions of all candidate genetic variants and non-genetic factors and has higher statistical power than previous approaches. To account for the within-subject dependence structure, we propose a grid-based approach that models only one fixed-dimensional covariance matrix, which is thus applicable to data where subjects have different numbers of time points. We provide the theoretical basis of our Bayesian method and then illustrate its performance using data from the 1000 Genome Project with various simulation settings. Several simulation studies show that our multivariate method increases the statistical power compared to the corresponding univariate method and can detect gene-time/ environment interactions well. We further evaluate our method with different numbers of individuals, variants, and causal variants, as well as different trait-heritability, and conclude that our method performs reasonably well with various simulation settings.

Identification of Focus Information with Contextual and Lexical Cues by Korean Learners of English: Evidence from Reaction Times Analyzed by Linear Mixed-Effect Models

Wonil Chung,Bum-Sik Park 한국영어학회 2019 영어학 Vol.19 No.4