An ERP Study On The Semantic Processing Of Unambiguous Noun, Unambiguous Verb And Verb-noun Ambiguous Word In Mandairn Chinese

Nouns and verbs exist in almost all human languages. As fundamental andimportant members of word classes, nouns and verbs differ but correlate at severallevels of language, including grammatical, semantic, pragmatic levels and so on.However, because of simple system of inflections, Chinese word classes could not bedistinguished by means of morphology. It has not reached an agreement on thecriteria of ascertaining word classes of Chinese. The researches from psycholinguistic,neurolinguistic and other perspectives may shed light on solving this problem becausethere is strong relationship between brain and language. Brain consists of two distinctcerebral hemispheres, left hemisphere and right hemisphere. The functions of eachhemisphere are specialized and lateralized. It is significant to explore therepresentation and processing of Chinese noun and verb in the left and righthemispheres for unfolding the secrets of bran, language and their relationship.The study was intended to investigate the semantic processing of unambiguousnoun, unambiguous verb and verb-noun ambiguous word in Chinese by means ofevent-related potentials (ERP) and tachistoscopic visual half-field technique. In orderto clarify the roles of semantic feature and concreteness in the word processing, theresults of the processing of verb and verb-noun ambiguous were further analyzed bycomparing the situations in which the variable of concreteness was matched and notmatched. The hemispheric lateralization of language was also discussed on the basisof the representation of noun, verb and verb-noun ambiguous showed in left visualfield/right hemisphere and right visual field/left hemisphere.The main results of the study are as follows:1. Chinese noun and verb, as fundamental members of word classes, representeddifferently in the semantic processing. There were significant differences betweennoun and verb on the amplitudes of P2and N400in the normal visual field.Furthermore, in the half visual field, the amplitudes of N400elicited by noun weresignificantly different from those elicited by verb. These results indicated the distinctsemantic features and concreteness of noun and verb, which did not support the hypotheses that noun and verb dissociation were at the level of grammaticalmorphology or at the level of syntax. And the results also did not support the pointthat noun-verb dissociation attributed to the semantic difference on the concreteness.2. Chinese verb-noun ambiguous word, as the intervals of the continuum of nounand verb, formed specific semantic features different from the two extreme points.Although achieving the syntactic functions of noun and verb, Chinese verb-nounambiguous did not achieve the semantic features of these two word classescorrespondingly. In contrast, the semantic features of verb-noun ambiguous weredistinct from those of noun and verb. The results of N400and LPC showed suchdifferences and indicated the category shift from verb to noun in semantic. In addition,the results also indicated that before entering syntactic position, verb-noun ambiguoushad already made semantic preparations for realizing both syntactic functions of nounand verb, which provided the supporting evidence for the conformance of syntaxlevel and semantic level.3. The variable of concreteness, which functioned as an important role in thelanguage processing, had greater effect on the representation and processing of nounthan on that of verb. The differences between the amplitudes of N400elicited byconcrete and abstract noun were more significant than those elicited by concrete andabstract verb. This was because noun that designated men and things was moresuitable to be analyzed on the dimension of concreteness than verb that referred toaction and behaviors.4. The functions of left and right hemisphere were separate and complementary.In the word processing, the left hemisphere is generally functionally specialized forsemantic and right hemisphere is generally lateralized for image. Furthermore, the lefthemisphere focused semantic activation on features related to the one and dominantmeaning and the right hemisphere maintained diffuse semantic activation on featuresrelated to several and less important meanings.5. N400contained at least two sub-components, one related to semantic featuresand the other related to concreteness. LPC component was the reflection ofconfidence in the lexical decision process. Polysemy activated higher LPC than singlemeaning word did.