The ability to string together words into a structured arrangement capable of conveying nuanced information is key to speech production. The assessment of the neural bases for structuring sentences has been challenged by the need of experts to delineate the aberrant morphosyntactic structures in aphasic speech. Most studies have relied on focused tasks with limited ecological validity. We characterized syntactic complexity during connected speech produced by patients with chronic post-stroke aphasia. We automated this process by employing Natural Language Processing (NLP). We conducted voxel-based and connectome-based lesion-symptom mapping to identify brain regions crucially associated with sentence production and syntactic complexity. Posterior-inferior aspects of left frontal and parietal lobes, as well as white matter tracts connecting these areas, were essential for syntactic complexity, particularly the posterior inferior frontal gyrus. These findings suggest that sentence structuring during word production depends on the integrity of Broca’s area and the dorsal stream of language processing.

将单词串在一起形成能够传达细微信息的结构化排列的能力是语音生成的关键。专家需要在失语症中描述异常的形态句法结构，这对构建句子的神经基础的评估提出了挑战。大多数研究都依赖于生态有效性有限的重点任务。我们描述了慢性卒中后失语症患者产生的连接语音过程中的句法复杂性。我们通过使用自然语言处理 (NLP) 来自动化这个过程。我们进行了基于体素和基于连接组的病变症状映射，以识别与句子生成和句法复杂性密切相关的大脑区域。左额叶和顶叶的后下方，以及连接这些区域的白质束，对于句法复杂性至关重要，尤其是额后下回。这些发现表明，单词生成过程中的句子结构取决于 Broca 区域的完整性和语言处理的背流。