Imaging Studies of Normal and Impaired Lexical Retrieval

描述（由申请人提供）：对正常受试者和神经系统患者的研究表明，左下和颞极皮层的完整性对正常的词汇-语义过程至关重要，并且这些过程的解剖学基础部分地被概念类别隔离。 我们将探讨这些区域在词汇加工中的作用，使用两个经验性的影响（语义干扰和词频效应），分别从不同的需求词汇选择和语音代码激活。这些影响的生理相关性，测量功能磁共振成像（fMRI），将照亮左外侧裂颞叶在正常的词汇处理的作用，并澄清是否专门参与词汇处理的神经区域被隔离的概念范畴。 最后，我们将利用一个独特的患者登记，包括后天左颞叶损伤和失名的主题。 我们将使用功能磁共振成像技术，隔离成功的命名试验的相关性，在这些科目的语义干扰和词频效应的相关性。这些结果将阐明首选神经系统受损后残留词汇提取的神经基础。这里进行的研究解决了可塑性，恢复以及与语言和记忆相关的系统的相互作用等更广泛的问题，并将促进功能磁共振成像技术适应语言障碍患者，它可用于跟踪疾病和恢复的过程，以及对治疗的反应。

DESCRIPTION (provided by applicant): Studies of normal subjects and neurological patients show that the integrity of the left inferior and polar temporal cortex is critical to normal lexical-semantic processes, and that the anatomic substrates of these processes are partially segregated by conceptual category. We will probe the role of these regions in lexical processing using two empirical effects (the semantic interference and word frequency effects) that arise from differential demands on lexical selection and phonological code activation, respectively. The physiologic correlates of these effects, measured with functional magnetic resonance imaging (fMRI), will illuminate the role of the left extrasylvian temporal lobe in normal lexical processing, and clarify whether neural regions specifically involved in lexical processing are segregated by conceptual category. Finally, we will take advantage of a unique Patient Registry including subjects with acquired left temporal lobe damage and anomia. We will examine the correlates of the semantic interference and word frequency effects in these subjects using fMRI techniques that isolate the correlates of successful naming trials. The results will clarify the neural basis for residual lexical retrieval after damage to preferred neural systems. The studies undertaken here address wider issues of plasticity, recovery, and the interplay of systems related to language and memory, and will promote adaptation of fMRI imaging technology to language-impaired patients, in whom it may be used to track the course of disease and recovery, as well as responses to treatment.