本文研究中国学习者加工句子层面的英汉汉英宾语语码转换时的认知神经机制。结果表明(1)加工英汉语码转换时，转换后的单词诱发更大P200和N400；(2)加工汉英语码转换时，转换后的单词诱发更大的LAN和LPC；(3)英汉汉英转换代价的非对称性表现在汉英比英汉语码转换产生更大的P200、LAN和LPC。据此，我们认为在句子层面存在英汉汉英宾语语码转换效应及其非对称性，并基于IC 模型与BIA+模型，构建了宾语语码转换的加工模型。

The present study investigated the underlying cognitive and neural mechanisms of object code switching in sentence contexts from Chinese to English (L1-L2) and from English to Chinese (L2-L1) for Chinese learners of English. ERP data analyses indicated that (1) code switched English objects produced significantly larger P200 and N400 than non-code switched English objects did; (2) code switched Chinese objects elicited significantly larger LAN and LPC than non-code switched Chinese objects did; (3) the asymmetry of switching cost from Chinese to English and from English to Chinese existed in larger P200, LAN and LPC for code switching from English to Chinese. We concluded that there existed intra-sentential code switching effects and corresponding asymmetry of switching costs for Chinese learners of English in terms of objects at sentence level, and the models for code switching effects and asymmetry of switching costs are tentatively built based on IC Model and BIA+ Model to provide a better explanation for the results.