Word-production theories argue that during language production, a concept activates multiple lexical candidates in left temporal cortex, and the intended word is selected from this set. Evidence for theories on spoken-word production comes, for example, from the picture-word interference task, where participants name pictures superimposed by congruent (e.g., picture: rabbit, distractor “rabbit”), categorically related (e.g., distractor “sheep”), or unrelated (e.g., distractor “fork”) words. Typically, whereas congruent distractors facilitate naming, related distractors slow down picture naming relative to unrelated distractors, resulting in semantic interference. However, the neural correlates of semantic interference are debated. Previous neuroimaging studies have shown that the left mid-to-posterior STG (pSTG) is involved in the interference associated with semantically related distractors. To probe the functional relevance of this area, we targeted the left pSTG with focal repetitive transcranial magnetic stimulation (rTMS) while subjects performed a picture-word interference task. Unexpectedly, pSTG stimulation did not affect the semantic interference effect but selectively increased the congruency effect (i.e., faster naming with congruent distractors). The facilitatory TMS effect selectively occurred in the more difficult list with an overall lower name agreement. Our study adds new evidence to the causal role of the left pSTG in the interaction between picture and distractor representations or processing streams, only partly supporting previous neuroimaging studies. Moreover, the observed unexpected condition-specific facilitatory rTMS effect argues for an interaction of the task- or stimulus-induced brain state with the modulatory TMS effect. These issues should be systematically addressed in future rTMS studies on language production.

单词生成理论认为，在语言生成过程中，一个概念会激活左颞皮层的多个候选词汇，并从该集合中选择想要的单词。例如，口语生成理论的证据来自图词干扰任务，其中参与者命名由一致的图像叠加的名称（例如，图片：兔子，干扰项“兔子”），绝对相关的（例如，干扰项“羊”） ），或不相关的（例如，分散注意力的“叉子”）单词。通常，虽然一致的干扰项有利于命名，但相关的干扰项相对于不相关的干扰项会减慢图片命名的速度，从而导致语义干扰。然而，语义干扰的神经关联存在争议。先前的神经影像学研究表明，左侧中后部 STG (pSTG) 参与了与语义相关干扰项相关的干扰。为了探讨该区域的功能相关性，我们在受试者执行图词干扰任务的同时，对左侧 pSTG 进行局灶性重复经颅磁刺激 (rTMS)。出乎意料的是，pSTG刺激并没有影响语义干扰效应，而是选择性地增加了一致性效应（即，用一致性干扰项更快地命名）。促进性 TMS 效应选择性地出现在较难的列表中，且总体名称一致较低。我们的研究为左侧 pSTG 在图片和干扰表征或处理流之间的相互作用中的因果作用添加了新的证据，但仅部分支持了之前的神经影像学研究。此外，观察到的意想不到的条件特异性促进性 rTMS 效应表明任务或刺激诱导的大脑状态与调节性 TMS 效应之间存在相互作用。这些问题应该在未来的 rTMS 语言产生研究中系统地解决。