Brain oscillatory dynamics in lexical-semantic processing

描述(申请人提供)：当大脑获得一个单词的意义时，它经历了两种类型的词汇语义加工：自动加工和控制加工。自动过程不在有意识的控制下，而受控的过程可以在有意识的控制下。参与这些类型加工的语言网络的不同之处在于，自动加工主要在左侧颞叶招募区域，而受控加工主要在左侧颞叶和左侧前额叶皮质招募区域。但描述某些过程中涉及的解剖区域只能让我们对支持这些过程的静态网络有一个感觉。我们建议研究如何通过大脑振荡的同步机制来创建词汇-语义处理的动态网络。已经提出，脑振荡的同步能够动态地招募本地神经种群，并连接遥远的种群进行通信。可以使用脑电并分析数据的时间、频率、相位和幅度来测量振荡的同步性。我们建议将这些方法用于研究自动和受控词汇-语义加工的新应用。本研究的目的是研究自动和受控(特定受控的单义选择)词汇-语义加工过程中左额叶和左额叶皮层的局部同步性和左额颞叶网络的远距离同步性；在这项研究中，我们将使用两种语义语境范式。我们还将研究失语症患者词汇-语义网络的动态形成是如何被扰乱的，以期了解他们的语言理解障碍。 与公共卫生的相关性：一些后天性语言障碍患者在理解单词的含义方面存在困难。虽然我们知道大脑的哪些区域支持这种语言功能，但我们并不完全了解这些区域是如何交流的。脑区通讯的中断可能与患者的问题有关。这项研究将帮助研究人员了解大脑区域如何在未受损和受损的语言人群中进行沟通，这是了解患者缺陷和可能的治疗策略的关键步骤。

DESCRIPTION (provided by applicant): When the brain accesses the meaning of a word, it undergoes two types of lexical-semantic processing: automatic and controlled. Automatic processes are not under conscious control, while controlled processes can be. The language networks involved in these types of processes differ in that automatic processes mostly recruit areas in the left temporal lobe while controlled processes recruit areas in both the left temporal lobe and the left prefrontal cortex. But describing the anatomical areas involved in certain processes can only give us a sense of the static network that supports these processes. We propose to investigate how a dynamic network for lexical-semantic processing may be created through the mechanism of synchronization of brain oscillations. It has been proposed that synchronization of brain oscillations is able to dynamically recruit local neural populations and connect far away populations for communication. Synchronization of oscillations can be measured using EEG and analyzing the time, frequency, phase, and amplitude of the data. We propose to use these methods in the novel application of studying automatic and controlled lexical-semantic processing. The aims of this project are to study local synchronization in the left temporal and prefrontal cortices and long- distance synchronization over the left fronto-temporal network in automatic and controlled (specifically controlled single meaning selection) lexical-semantic processes; in this endeavor, we will utilize two semantic context paradigms. We will also examine how the dynamic formation of the lexical-semantic network may be disrupted in aphasics as a possible insight into their language comprehension impairments. PUBLIC HEALTH RELEVANCE: Some patients with an acquired disorder of language have trouble accessing the meanings of words. While we know which brain areas support this language function, we do not fully understand how these areas communicate. Disruptions in the communication of brain areas may be related to the patients' problems. This study will help researchers understand how brain areas communicate in both unimpaired and impaired language populations which are crucial steps towards understanding patients' deficits and possible treatment strategies.