词汇加工初期语义属性的激活程度:来自ERP的证据

The Activation of Semantic Information in Early Stage of Word Recognition:Evidence from an ERP Study

运用事件相关脑电位(ERP)技术,采用快速掩蔽启动范式和Go/Nogo范式,探讨汉语重复启动和语义相关启动中语义激活程度的差异和特点。实验中要求被试执行一个额外的语义判断任务,对关键刺激不做明显的行为反应。结果发现,在重复启动条件下获得了稳定的N400效应,语义相关启动条件下没有N400效应;重复启动和语义相关启动条件均未产生N250效应。在较短的SOA条件下,词频对语义的激活和加工不产生影响。

The semantic understanding of written words are fundamental to the process of reading. In the word recognition research, such as alphabet writing, many studies have shown that repetition and semantic priming both produce characteristic differences in ERPs. The most frequently reported effect is that the primed words attenuate the N400 component compared to non-primed words. Such 51400 ＂effects＂ are believed to be sensitive to the lexical and/or semantic properties of the stimulus and its context. However, there is a promi- nent debate about the meaning that the N400 effects reflected in the semantic processing. The Chinese characters are ideograms, which are different from the alphabetic script in strokes, structures and orthographic processing, etc. The present study used event-related po- tential recordings （ERPs） to explore the traits of semantic processing of Chinese characters by adopting short intervals masked priming and Go/Nogo paradigms. In order to avoid subjects using the different strategies across experiments, semantic/associated and repetition trials were included within a single session. Fifteen students were randomly chosen from a university. We adopted a 2 （Word Frequency： High and Low） ~ 3 （Priming Relationship： repetition priming, associative priming and control condition） within subjects design. Participants performed a semantic categorization task, in which they were instructed to monitor all stimuli for occasional exemplars （probes） from the category of animal names. Meanwhile, there was no requirements to the critical prime or target stimuli. The results showed that in a short SOA （47ms）, the 51400 effects between the repetition priming and the control condition had sig- nificant difference. At the same time, the difference between repetition priming and associative priming was also significant. However, there were no significant differences between the associative priming and the control condition. For the earlier component of the N250, there was no evidence of any differences in all priming relationship conditions. Moreover, word frequency did not affect the semantic processing. In conclusion, the current study demonstrated a robust N400 effect in the repetition priming condition. However, there was no sig- nificant N400 effect in the associative priming condition. The N400 effects of repetition priming in Chinese character may also partly re- flect the processing at a form-meaning interface that is sensitive to the compatibility of co-activated form and meaning representations. According to this study and the previous research, we tentatively conclude that the orthographic processing between Chinese characters and alphabetic script word may be different, and the former is much more likely to be the whole processing.