Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany.
Section Neurological Cognition Research, Department of Neurology, Uniklinik RWTH Aachen Aachen, Germany ; Department of Psychiatry, Psychotherapy and Psychosomatics, Uniklinik RWTH Aachen Aachen, Germany ; Research Centre Juelich, Institute of Neuroscience and Medicine (INM-1) Juelich, Germany.
Front Psychol. 2014 Mar 21;5:246. doi: 10.3389/fpsyg.2014.00246. eCollection 2014.
Functional brain imaging studies have improved our knowledge of the neural localization of language functions and the functional reorganization after a lesion. However, the neural correlates of agrammatic symptoms in aphasia remain largely unknown. The present fMRI study examined the neural correlates of morpho-syntactic encoding and agrammatic errors in continuous language production by combining three approaches. First, the neural mechanisms underlying natural morpho-syntactic processing in a picture description task were analyzed in 15 healthy speakers. Second, agrammatic-like speech behavior was induced in the same group of healthy speakers to study the underlying functional processes by limiting the utterance length. In a third approach, five agrammatic participants performed the picture description task to gain insights in the neural correlates of agrammatism and the functional reorganization of language processing after stroke. In all approaches, utterances were analyzed for syntactic completeness, complexity, and morphology. Event-related data analysis was conducted by defining every clause-like unit (CLU) as an event with its onset-time and duration. Agrammatic and correct CLUs were contrasted. Due to the small sample size as well as heterogeneous lesion sizes and sites with lesion foci in the insula lobe, inferior frontal, superior temporal and inferior parietal areas the activation patterns in the agrammatic speakers were analyzed on a single subject level. In the group of healthy speakers, posterior temporal and inferior parietal areas were associated with greater morpho-syntactic demands in complete and complex CLUs. The intentional manipulation of morpho-syntactic structures and the omission of function words were associated with additional inferior frontal activation. Overall, the results revealed that the investigation of the neural correlates of agrammatic language production can be reasonably conducted with an overt language production paradigm.
功能脑成像研究提高了我们对语言功能的神经定位以及病变后功能重组的认识。然而，失语症中语法障碍的神经相关性仍知之甚少。本 fMRI 研究通过结合三种方法，研究了连续语言产生中形态句法编码和语法错误的神经相关性。首先，在 15 名健康演讲者的图片描述任务中分析了自然形态句法处理的神经机制。其次，通过限制句子长度，在同一组健康演讲者中诱导类似语法的言语行为，以研究潜在的功能过程。在第三种方法中，五名语法障碍参与者执行图片描述任务，以深入了解语法障碍的神经相关性以及中风后语言处理的功能重组。在所有方法中，句子都进行了句法完整性、复杂性和形态学分析。通过将每个类句单元 (CLU) 定义为具有起始时间和持续时间的事件，进行了事件相关数据分析。对比了语法和正确的 CLU。由于样本量小，以及病变大小和部位不均匀，病变焦点在脑岛叶、额下回、颞上回和顶下小叶，因此对语法障碍者的激活模式进行了单个体水平分析。在健康演讲者组中，后颞叶和顶下小叶与完整和复杂 CLU 中更大的形态句法需求相关。形态句法结构的有意操纵和功能词的省略与额外的额下回激活相关。总的来说，研究结果表明，通过显性语言产生范式合理地研究语法语言产生的神经相关性是可行的。
