Exploring the expressive language function of the supplementary motor area

项目摘要 该奖学金的目标是提供优秀的多学科培训，在心理语言学，功能 通过发展对表达的机械理解的神经解剖学和颅内神经生理学 内侧额壁多个区域，特别是辅助运动区的语言功能 (SMA)和PreSMA。这些区域的功能障碍与各种运动和语言障碍有关 包括运动启动和排序、发音、句子规划以及演讲的问题 包括发育性口吃在内的疾病。SMA已经在非发声方面进行了研究 人类灵长类动物模型，但前SMA和SMA在语言产生中的功能作用只能是 在人类身上进行了探索。虽然内侧额壁有多个运动和语音关键皮质区， 这一建议假设前SMA和SMA在言语/语言和运动中都有独特的作用 生产，前者参与动作的选择，后者参与动作的排序。根据假设， PreSMA涉及语言和运动功能中的元素和序列的选择，而SMA 语音和运动程序的顺序(例如，发音)。当这些区域与不同的 皮质下和皮质区域，序列和选择是区分激活的关键变量 这些区域在语言和运动任务中都存在。关键的是，我们假设相同的区域表现出 运动和语言任务中的选择(前SMA)和排序(SMA)。为了回答这个问题，我们将 慢性植入癫痫患者(N=20)的体感诱发脑电(SEEG)颅内记录 结合神经心理测试和功能核磁共振检查。在目标1中，我们将调查 运动和语言任务中的排序与选择(重复与生成手指敲击序列 和音节)与前SMA和SMA中的宽带伽马活动有关。我们假设前SMA和SMA 将在选择(生成)条件下为运动和语言任务激活，同时进行排序 (重复)仅激活SMA的任务。然后，我们将调查PreSMA/SMA到 理解与语言相关的信息是如何被传输到该区域以达到语音目的的 制作。在目标2中，我们将首先使用SEEG皮质-皮质诱发电位来显示直接有效 前SMA/SMA和语言区域之间的连接，包括语言运动皮质(输出)，下部 额回(语音选择)和后中回(语义选择)。然后我们将使用 SEEG功能连接，以证明语言区域的功能连接在 语言任务与运动任务的比较。这里提出的跨学科方法将把 前SMA/SMA的功能神经解剖学对表达语言的心理语言学分析。翻译成 临床实践表明，我们的研究成果将对包括口吃在内的言语障碍有更好的认识，提高 功能脑地形图，阐明SMA综合征语言功能障碍的机制。

Project Summary The goal of this fellowship is to provide excellent multidisciplinary training in psycholinguistics, functional neuroanatomy, and intracranial neurophysiology by developing mechanistic understanding of expressive language function in the multiple regions in the medial frontal wall, specifically the supplementary motor area (SMA) and preSMA. Dysfunction in these regions has been tied to a variety of motor and language deficits including issues with motor initiation and sequencing, articulation, and sentence planning as well as speech disorders including developmental stuttering. The SMA has been studied with respect to vocalization in non- human primate models, but the functional role of the preSMA and SMA in language production can only be explored in humans. While there are multiple motor and speech-critical cortical areas in the medial frontal wall, this proposal hypothesizes that the preSMA and SMA have unique roles in both speech/language and motor production, with the former involved in selection of action and the latter in sequencing of action. By hypothesis, PreSMA is involved in selection of elements and sequences in language and motor functions, while SMA sequencing of speech and motor programs (e.g. articulation). While these regions interact with different subcortical and cortical regions, sequence vs. selection is a critical variable that distinguishes activation in these regions in both language and motor tasks. Critically, we hypothesize that the same regions perform selection (preSMA) and sequencing (SMA) in motor and language tasks. To answer this question, we will utilize stereo EEG (SEEG) intracranial recording in chronically-implanted epilepsy patients (N=20) in conjunction with neuropsychological testing and functional MRI. In Aim 1, we will investigate the relationship of sequencing vs. selection in motor and language tasks (repetition vs. generation of sequences of finger taps and syllables) to broadband gamma activity in the preSMA and SMA. We hypothesize that preSMA and SMA will be activated in the selection (generation) condition for both motor and language tasks, while sequencing (repetition) tasks that will activate only SMA. We will then investigate the connectivity of the preSMA/SMA to understand how language-relevant information is transferred to this region for the purposes of speech production. In Aim 2, we will first use SEEG cortico-cortical evoked potentials to show direct effective connectivity between preSMA/SMA and language regions including speech motor cortex (output), inferior frontal gyrus (phonologic selection), and posterior middle temporal gyrus (semantic selection). We will then use SEEG functional connectivity to demonstrate that functional connectivity to language regions increases during language tasks in comparison to motor tasks. The cross-disciplinary approach proposed here will tie the functional neuroanatomy of preSMA/SMA to psycholinguistic analyses of expressive language. Translated into clinical practice, our results will create a better understanding of speech disorders including stuttering, improve functional brain mapping, and elucidate the mechanisms of language dysfunction in SMA syndrome.