中文摘要：

目的研究汉语成语尾字匹配与非匹配事件相关脑电位（ERP）N400的变化，探讨其认知模式以及汉字认知加工特点。方法应用国产WJ-1型ERP仪，对62名19～50岁健康成人右利手受试者，进行汉语成语正常结尾字（匹配）与汉语成语结尾歧义字（非匹配）N400检测，比较两种情况下N400波形、潜伏期和波幅，并测试实验结果的稳定性，观察性别对结果的影响。结果①N400基本波型分布于Fz、cz和Pz等各脑区。②健康成人尾字匹配和非匹配组的N400潜伏期和波幅差异有统计学意义（P〈0．05～0．01），非匹配组的N400较匹配组的N400潜伏期长、波幅高。③N400的潜伏期及波幅随刺激类型不同而变化，主要表现为异音异形异义组潜伏期最长和波幅最大。结论汉语与西文相比词的变化更多，包括音、形、义的不同搭配使N400研究更复杂。汉语成语尾字匹配和非匹配的N400与字词认知中的语义有关。

英文摘要：

Objective To investigate the use of component N400 of the event-related potentials （ERPs） elicited by Chinese idioms ending with matching and nonmatching words to explore the cognitive patterns and processing mechanisms elicited by Chinese characters. Methods Sixty-two right-handed healthy adults （age 19-50 years） , were presented with Chinese idioms ending with words with the same pronunciation but different form and meaning, words with similar forms but different pronunciation and meaning, words with same meaning but different pronunciation and form, and words with different pronunciation, form and meaning. A Guangzhou Runjie W J-1 instrument was used to record component N400 of the potentials evoked. Results N400 showed a midline distribution, and could be detected under electrodes Fz, Cz and Pz. Significant differences were found in N400 latencies and amplitudes between matching and nonmatching ending-words. Compared with idioms with matching ending- words, N400 lateneies were prolonged and amplitudes increased in nomnatching cases. The observed changes in N400 latencies and amplitudes were related to stimulus types, and the longest latency and largest amplitude were e- licited by ending-words with different pronunciation, form and meaning. No gender difference in N400 latency or amplitude was observed. Conclusions Compared with Western phonetic words, Chinese ideographic words are more flexible stimuli for N400 research, offering 3 dimensions for change： pronunciation, form and meaning. The N400 features elicited by matching and nonmatching ending words in Chinese idioms are mainly determined by the meaning of the word.