The frontal aslant tract (FAT) is a white-matter tract connecting the inferior frontal gyrus (IFG) and the supplementary motor complex (SMC). Damage to either component of the network causes spontaneous speech dysfluency, indicating its critical role in language production. However, spontaneous speech dysfluency may stem from various lower-level linguistic deficits, precluding inferences about the nature of linguistic processing subserved by the IFG-SMC network. Since the IFG and the SMC are attributed a role in conceptual and lexical selection during language production, we hypothesized that these processes rely on the IFG-SMC connectivity via the FAT. We analysed the effects of FAT volume on conceptual and lexical selection measures following frontal lobe stroke. The measures were obtained from the sentence completion (SC) task, tapping into conceptual and lexical selection, and the picture-word interference (PWI) task, providing a more specific measure of lexical selection. Lower FAT volume was not associated with lower conceptual or lexical selection abilities in our patient cohort. Current findings stand in marked discrepancy with previous lesion and neuroimaging evidence for the joint contribution of the IFG and the SMC to lexical and conceptual selection. A plausible explanation reconciling this discrepancy is that the IFG-SMC connectivity via the FAT does contribute to conceptual and/or lexical selection but its disrupted function undergoes reorganisation over the course of post-stroke recovery. Thus, our negative findings stress the importance of testing the causal role of the FAT in lexical and conceptual lexical selection in patients with more acute frontal lobe lesions.

中文翻译：

---

左额叶倾斜道和词汇选择：来自额叶病变的证据。

额斜道（FAT）是连接下额回（IFG）和辅助运动复合体（SMC）的白色物质。网络任一部分的损坏都会导致语音自发性流失，表明其在语言产生中的关键作用。但是，自发的言语失调可能源于各种较低级别的语言缺陷，从而排除了有关IFG-SMC网络所服务的语言处理性质的推论。由于IFG和SMC在语言生成过程中被归类为概念和词汇选择的角色，因此我们假设这些过程依赖于FAT通过IFG-SMC进行的连接。我们分析了额叶卒中后FAT量对概念和词汇选择指标的影响。这些措施是从句子完成（SC）任务中获得的，利用概念和词汇选择以及图片词干扰（PWI）任务，提供了更具体的词汇选择度量。在我们的患者队列中，较低的FAT量与较低的概念或词汇选择能力无关。目前的发现与IFG和SMC对词汇和概念选择的共同贡献的先前病变和神经影像学证据明显不同。弥补这一差异的一个合理解释是，通过FAT进行的IFG-SMC连接确实有助于概念和/或词汇选择，但是其功能中断会在中风后恢复过程中进行重组。从而，