Cross-Linguistic Studies of Aphasia

对失语症的跨语言研究使我们能够将普遍机制与语言特有的内容分开。跨语言研究揭示了在正常和异常情况下可能发生的变异范围，也解决了行为和神经可塑性的关键问题。在这项研究中，我们概述了三种语言(英语、意大利语和汉语)在词汇和语法结构(如词序变异的数量、词形变化、成分遗漏、词和语素的一致性与不规则性、词汇歧义的可能性以及词的内部结构)上存在显著差异的失语症患者和对照组的语言加工和语言崩溃的新的比较研究。患者研究(病变-行为图谱的经典方法)得到了以相同三种语言(使用功能磁共振成像，或fMRI)的正常人脑成像研究的补充。同样的材料也被用在行为和功能磁共振实验中，用于计算机控制的在线任务中，这些任务产生关于单词和句子处理的时间动态信息。非语言控制任务的设计是为了在关键方面(视觉、听觉和运动激活；对记忆、注意力和决策的要求)与语言任务相匹配，测试关于通道和感觉运动需求对语言激活(FMRI)和语言崩溃(损伤研究)的贡献的假设。我们还扩展了“正常控制”的概念，以包括在不利的加工条件(知觉退化、时间压缩、认知过载)下测试的正常比较，以发现加工中的“断点”，并在患者中“模拟”加工障碍。文字和图片刺激的选择是基于上一个资金周期在所有地点收集的大量规范信息。研究中的失语症亚组包括不流利的布罗卡氏失语症、流利的韦尼克失语症，以及很少犯明显语法错误但仍难以找到合适单词的失语症患者。认识到传统失语症分类的局限性，我们也采取了一种新的多变量方法，在连续的多维症状空间内分析患者的实验表现，该空间通过使用大型档案数据集(每种语言超过200名患者)为每种语言定义。结果是在两个理论框架的合并中解释的：竞争模型(一种假设分布式概率表征上的交互激活的加工模型)和体现理论(语言的神经组织理论)。

Cross-linguistic studies of aphasia permit us to separate universal mechanisms from language-specific content. By uncovering the range of variations that are possible under normal and abnormal conditions, cross-language studies also address the critical issues of behavioral and neural plasticity. In this proposal, we outline new comparative studies of language processing and language breakdown in aphasic patients and controls in three languages (English, Italian and Chinese) that differ dramatically in their lexical and grammatical structure (e.g. amounts of word order variation, inflectional morphology, constituent omission, consistency vs. irregularity of words and morphemes, potential for lexical ambiguity, and the internal structure of words). Patient studies (the classical method of lesion-behavior mapping) are complemented by brain-imaging studies of normals in the same three languages (using functional magnetic resonance imaging, or fMRI). The same materials are used in behavioral and fMRI experiments, in 'on-line', computer- controlled tasks that yield information about the temporal dynamics of word and sentence processing. Nonverbal control tasks are designed to match linguistic tasks in key respects (visual, auditory, and motor activation; demands on memory, attention, decision-making), testing hypotheses about the contributions of modality and sensorimotor demands to language activation (fMRI) and language breakdown (lesion studies). We also expand the concept of "normal control" to include comparisons of normal tested under adverse processing conditions (perceptual degradation, temporal compression, cognitive overload), to uncover 'breakpoints' in processing and to 'simulate' processing disorders in patients. Selection of word and picture stimuli is based on massive norming information collected at all sites in the last funding cycle. The aphasia subgroups under study include nonfluent Broca's aphasics, fluent Wernicke's aphasics, and anomic patients who commit few overt grammatical errors but still struggle to 'find the right word'. Acknowledging the limitations of traditional aphasia categories, we also take a new multivariate approach, analyzing patients' performance on experiments within a continuous, multidimensional symptom space, defined for each language by using large archival data sets (more than 200 patients per language). Results are interpreted within a merger of two theoretical frameworks: the Competition Model (a processing model that assumes interactive activation over distributed, probabilistic representations) and Embodiment Theory (a theory of neural organization for language).