An ERP Analysis of the World-Sense and Semantics Mismatches
in Japanese Sentences
Yu Odagaki,

Sakriani Sakti,

Graham Neubig,

Tomoki Toda,

Satoshi Nakamura

P2-k18

Augmented Human Communication Laboratory NAIST
Introduction

The effect of mistaken words on the sentence comprehension process has been studied for Western languages. In a previous study, if a sentence has aword that violates semantic or world knowledge violation word, N400 ERP component appears during the reading of the sentence (Hagort et al., 2004).
Our study presented in this paper used electroencephalography (EEG) to examine whether the process of finding incorrect words due to semantic orworld knowledge violation in Japanese sentences is the same as the process in Western languages.

MethodIn the experiment, we presented three kinds of sentences as visual stimuli. The first ones were completely correct sentences, the next ones included a word that violated world knowledge, and the last ones included a wordthat violated semantics. An example of the sentence is “Japanese Shinkansen is white/black/irritable and veryfast”. The first version of the sentence is understandable and correct. The alternative color of black is easy to understand. However, it is well known that the Japanese Shinkansen is white. Therefore, this version of sentence isfalse. The last one has a violation of semantic constraint. Irritable is not suitable for explaining appearance oftrain.
Each sentence was split into segments. Each segment was shown to participants for 0.5 seconds with 0.5 secondintervals.

Example1) Correct
Japanese Shinkansen is white and very fast.
(新幹線は白くとても速い。)

2) World knowledge violation
Japanese Shinkansen is black and very fast.
(新幹線は黒くとても速い。)

3) Semantic violation
Japanese Shinkansen is irritable and very fast.
(新幹線は怒りっぽくとても速い。)

Participants
Of the 10 right-handed males tested, we selected 6
subjects because of the data of the remaining subjects were contaminated by noise. They are healthy
graduate school students, and native Japanese
speakers. They don’t have history of psychiatric orneurological illness or alcohol abuse. They have novisual deficit.

Interval of stimulus

1.0 [s]0.5 [s]0.5 [s]0.5 [s]0.5 [s]0.5 [s]0.5 [s]1.0 [s]ResultAs a result, a negative shift appeared after words that violated world
knowledge and semantics were presented. According to the Hagoort etal. (2004), the peak of this negative shift was shown to occur at about
400 ms which indicate the N400 component. However, the peak shownin this study occurred at about 350 ms in the parietal area (Cz). Amplitude of N400 also different from the previous study. According to theprevious study, differential of amplitude between World knowledge violation and semantic violation had no significant difference whereas inthis study, their ERPs showed a significant difference.
ERPs are time locked to the presentation of the critical word.
Difference of three kinds of ERPs were not identical [F=3.03,P<0,001]. The size of effect of semantic violations was larger
than World knowledge violations (P<0.001) and world
knowledge violations one was larger than correct (p<0.001).

Discussion
The result was similar to the previous study. This early N400 phenomenon indicates that Japanese words can be processed faster than those of Western
languages. It may be partly due to the processing of Japanese Kanji characters, which also similarly appeared in Chinese study (Zheng Ye et al., 2005).
Difference of N400 amplitude between world knowledge violation and semantic violations may come from the grammatical form of Japanese. In Japanese sentences, the reader cannot tell until the end of a sentence whether the sentence is true or not, so effect of N400 was reduced when world
knowledge violation words were presented.
Acknowledgement
Part of this research was executed under the Commissioned Research for ” Research and Development on Medical Communication Support System for Asian Languages based on Knowledge and Language Grid” ofNational Institute of Information and Communications Technology (NICT), Japan.

The 35th Annual Meeting of the Japan Neuroscience Society

An ERP Analysis of the World-Sense and Semantics Mismatches
in Japanese Sentences
Yu Odagaki,

Sakriani Sakti,

Graham Neubig,

Tomoki Toda,

Satoshi Nakamura

P2-k18

Augmented Human Communication Laboratory NAISTIntroduction
If a sentence has a word that violates semantic or world knowledge, N400 appears (Hagort et al., 2004)●Our study presented in this paper used electroencephalography (EEG) to confirm whether Japanese sentences cause
N400 ERP component●Method●

Presented three kinds of sentences as visual stimuli aresentences (3×90sentences)

●

●

●

1.Completely correct sentences

Each sentence was split into segments
Each segment was shown for 0.5 sec
Intervals of segments 0.5 sec

2.A word that violated world knowledge
3.A word that violated semantics

1.0s

Critical word Stimuli
1) Correct :understandable and correct

0.5s

0.5s

0.5s

0.5s

0.5s

0.5s

1.0s

Participants

Japanese Shinkansen is white and very fast.
(新幹線は白くとても速い。)●

2) World knowledge violation :understandable but not true●

Japanese Shinkansen is black and very fast.
●(新幹線は黒くとても速い。)
3) Semantic violation :has a violation of semantic constraint●

Japanese Shinkansen is irritable and very fast.

●

6 subjects
Healthy graduate school students
Native Japanese speaker
Not have history of psychiatric or neurological illness or alcohol abuse
No visual deficit(新幹線は怒りっぽくとても速い。)

Result●Negative shift appeared after critical words

Previous study (Hagoort et al., 2004):●●The peak of this negative shift was shown to occur at about
400 msWorld knowledge and semantic had no significant difference

In this study:●●

The peak occurred at about 350 ms (Cz)
ERPs showed a significant difference between world knowledge
and semantic violations

ERPs are time locked to the presentation of the critical word. Difference of
three kinds of ERPs were not identical[F=3.03, P<0,001]. The size of effectof semantic violations was larger than World knowledge violations(P<0.001)
and world knowledge violations one was larger than correct(p<0.001).

Discussion●Early N400 phenomenon indicates that Japanese words can be processed faster than those of Western languages⇒●●It may be partly due to the processing of Japanese Kanji characters, which also similarly appeared in Chinese study(Zheng Ye et al., 2005).

Difference of N400 amplitude between world knowledge violation and semantic violations may come from the grammatical form of Japanese
In Japanese sentences, the reader cannot tell whether a sentence is true or false until the end of a sentence

Acknowledgement
Part of this research was executed under the Commissioned Research for ” Research and Development on Medical Communication Support System for Asian Languages based on Knowledge and Language Gri d” of National Institute of Information and Communica-tions Technology (NICT), Japan.

The 35th Annual Meeting of the Japan Neuroscience Society