Non-fluent speech is one of the most common impairments in post-stroke aphasia. The rehabilitation of non-fluent speech in aphasia is particularly challenging as patients are rarely able to produce and practice fluent speech production. Speech entrainment is a behavioural technique that enables patients with non-fluent aphasia to speak fluently. However, its mechanisms are not well understood and the level of improved fluency with speech entrainment varies among individuals with non-fluent aphasia. In this study, we evaluated the behavioural and neuroanatomical factors associated with better speech fluency with the aid of speech entrainment during the training phase of speech entrainment. We used a lesion-symptom mapping approach to define the relationship between chronic stroke location on MRI and the number of different words per second produced during speech entrainment versus picture description spontaneous speech. The behavioural variable of interest was the speech entrainment/picture description ratio, which, if ≥1, indicated an increase in speech output during speech entrainment compared to picture description. We used machine learning (shallow neural network) to assess the statistical significance and out-of-sample predictive accuracy of the neuroanatomical model, and its regional contributors. We observed that better assisted speech (higher speech entrainment/picture description ratio) was achieved by individuals who had preservation of the posterior middle temporal gyrus, inferior fronto-occipital fasciculus and uncinate fasciculus, while exhibiting lesions in areas typically associated with non-fluent aphasia, such as the superior longitudinal fasciculus, precentral, inferior frontal, supramarginal and insular cortices. Our findings suggest that individuals with dorsal stream damage but preservation of ventral stream structures are more likely to achieve more fluent speech with the aid of speech entrainment compared to spontaneous speech. This observation provides insight into the mechanisms of non-fluent speech in aphasia and has potential implications for future research using speech entrainment for rehabilitation of non-fluent aphasia.

中文翻译：

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支持自发和辅助（携带）语音流利度的神经结构。

非流利的言语是中风后失语症最常见的障碍之一。由于患者很少能够产生和练习流利的言语产生，因此失语症中非流利的言语的康复尤其具有挑战性。言语训练是一种行为技术，可使患有非流利性失语症的患者说流利的语言。但是，其机制尚不十分清楚，并且非流失性失语症患者的语音夹带度提高的流利程度也有所不同。在这项研究中，我们在语音训练的训练阶段借助语音训练评估了与更好的语言流畅度相关的行为和神经解剖学因素。我们使用病变症状映射方法来定义MRI上的慢性卒中位置与语音夹带与图片描述自发语音之间每秒产生的不同单词数之间的关系。感兴趣的行为变量是语音夹带/图片描述比率，如果≥1，则表示与图片描述相比，语音夹带期间语音输出增加。我们使用机器学习（浅层神经网络）评估了神经解剖模型及其区域贡献者的统计显着性和样本外预测准确性。我们观察到，保留后中颞回的个体可以获得更好的辅助语音（较高的语音夹带/图片描述比率），额枕下筋膜和钩状筋膜，而在通常与非流利性失语相关的区域表现出病变，例如上纵筋膜，中央前额叶，额中下叶，上颌骨和岛状皮层。我们的研究结果表明，与自发性言语相比，具有背语流损伤但保留腹侧流结构的人更容易借助言语夹带获得更流畅的言语。该观察提供了对失语失语的非流利言语机制的洞察力，并且对于将来使用言语夹带对失语性失语症进行康复的研究具有潜在的启示。上皮和岛状皮层。我们的研究结果表明，与自发性言语相比，具有背语流损伤但保留腹侧流结构的人更容易借助言语夹带获得更流畅的言语。该观察提供了对失语失语的非流利言语机制的洞察力，并且对于将来使用言语夹带对失语性失语症进行康复的研究具有潜在的启示。上皮和岛状皮层。我们的研究结果表明，与自发性言语相比，具有背语流损伤但保留腹侧流结构的人更容易借助言语夹带获得更流畅的言语。该观察提供了对失语失语的非流利言语机制的洞察力，并且对于将来使用言语夹带对失语性失语症进行康复的研究具有潜在的启示。