Bilinguals differ substantially in their second language (L2) proficiency, but it remains unclear whether language proficiency modulates the effect of L2 semantically related distractors in L2 spoken word production. In the present study, two groups of high proficiency and low proficiency Chinese-English bilinguals named target pictures in their L2 accompanied by visually superimposed L2 distractor words while electroencephalogram signals were recorded. Distractor names were semantically related or unrelated to target names. Variables of L2 proficiency (high proficiency or low proficiency) and semantic relatedness (related or unrelated) were manipulated in the experiment. Behavioral results demonstrated an interaction between L2 proficiency and semantic relatedness, with a semantic interference effect appearing only in high proficiency bilinguals. Waveform analysis indicated that semantic relatedness only exerted significant effects on event-related potentials in high proficiency bilinguals around 300–500 ms post picture presentation. Source localization analysis revealed that semantically related distractors induced higher brain activations in the left middle and superior temporal regions among high proficiency bilinguals, while higher brain activations were found in the right prefrontal cortex among low proficiency bilinguals. Taken together, these findings substantiate the role of language proficiency in determining whether L2 semantically related distractors are sufficiently activated to exceed the competition threshold and interfere with L2 picture naming.

双语者的第二语言 (L2) 熟练程度差异很大，但目前尚不清楚语言熟练程度是否会调节 L2 语义相关干扰因素在 L2 口语产生中的影响。在本研究中，两组高熟练度和低熟练度的汉英双语者在他们的二语中命名目标图片，并伴有视觉叠加的二语干扰词，同时记录脑电信号。Distractor 名称在语义上与目标名称相关或无关。实验中操纵了 L2 熟练度（高熟练度或低熟练度）和语义相关性（相关或不相关）的变量。行为结果表明二语熟练度和语义相关性之间存在交互作用，语义干扰效应仅出现在高熟练度双语者身上。波形分析表明，语义相关性仅在图片呈现后 300-500 毫秒左右对高水平双语者的事件相关电位产生显着影响。源定位分析显示，语义相关的干扰因素在高熟练双语者的左侧中上和颞上区引起更高的大脑激活，而在低熟练度双语者的右前额叶皮层中发现更高的大脑激活。总之，这些发现证实了语言熟练程度在确定 L2 语义相关干扰项是否被充分激活以超过竞争阈值并干扰 L2 图片命名方面的作用。