P2a反映人脑对构词结构的识别:来自ERP的证据

P2a Reflects Morphology Structural Processes in Brain: Evidence from ERPs

为考察汉语复合词的偏正式、述补式等构词结构信息在视觉识别过程中是否有专门的作用,以及人脑何时识别这些构词结构信息这一问题,采用事件相关电位(event-related potentials,ERP)技术、视觉启动词汇判断实验.探讨启动词-目标词词对的语义(相关/无关)、构词结构(相同/不同)关系,实验发现:①在反应时上表现出极显著的语义启动效应,与启动刺激词语义相关的目标刺激词反应时更短,却未发现显著的构词结构启动效应.②在ERP数据上,额区P2a(150～180ms)仅发现了显著的构词结构启动效应,与启动刺激词构词结构相同的目标刺激词诱发了一个更大波幅的P2a,N400(320～360ms)上仅发现了显著的语义启动效应,与启动刺激词语义无关的目标刺激词诱发了一个更负的N400;且在P2a及N400成分上均未发现显著的构词结构×语义效应.研究认为,在汉语复合词的视觉识别早期阶段存在一个独立于语义的、纯粹的构词结构加工,且P2a(150～180ms)可反映该过程.

Whether Chinese compounds morphology structural information （e. g. , subordinative construction, verb-object construction, etc. ） has its special effect on visual word recognition and when the morphology structural information is processed in brain are not yet well understood. In this study, a visual primed lexical decision task with the technology of event related potential （ERP） was used to investigate the problem above, with the semantic （related/unrelated） and morphology structural （identical/distinct） relation of prime-target compound word pairs controlled. Behaviorally, a significant semantic priming effect was observed, with less reaction time for semantic related pairs compared to semantic unrelated pairs, while no significant morphology structural priming effect was detected in reaction time. Electrophysiologically, a significant morphology structural priming effect was only observed on anterior distribu- ted P2a （150--180 ms）, with a more positive P2a for morphology structurally identical pairs relative to morphology structurally distinct pairs; a significant semantic priming effect occurred only on N400 （320- 360 ms）, with a more negative N400 for semantically related pairs relative to semantically unrelated pairs; moreover, a statistically indistinguishable interaction of morphology structural relationship × semantic relationship was observed on either P2a or N400. The above results showed that the processing of Chinese compounding morphology structure occurs early in visual word recognition independent of lexico-semantic process, indicated by an early frontal distributed P2a（150-180 ms）.