Brain dynamics of lexical selection in speech production

言语产生中词汇选择的大脑动力学

• 批准号: 8700131
• 负责人: Stephanie Ries-Cornou
• 金额: $ 5.51万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8700131
• 关键词: Address; Adult; Anomia; Attention; Behavior; Brain; Brain Injuries; Brain imaging; Brain region; Coupling; Electrocorticogram; Electrodes; Electroencephalography; Electrophysiology (science); Evoked Potentials; Financial compensation; Frequencies; Functional Magnetic Resonance Imaging; Goals; Imaging Techniques; Individual; Inferior; Injury; Investigation; Knowledge; Laboratories; Language; Left; Linguistics; Measures; Medial; Memory; Metric; Modeling; Neurodegenerative Disorders; Neurologic; Neuronal Plasticity; Neurons; Patients; Pattern; Performance; Phase; Physiological; Physiology; Play; Prefrontal Cortex; Process; Production; Psyche structure; Recovery; Relative (related person); Research; Response to stimulus physiology; Role; Signal Transduction; Site; Speech; Stimulus; Stroke; Surface; Temporal Lobe; Testing; Time; Training Programs; aged; aphasic; base; behavior measurement; cognitive control; cognitive function; cost; experience; indexing; injured; language processing; lexical; lexical processing; memory retrieval; normal aging; novel; post stroke; public health relevance; relating to nervous system; response; skills; tool

DESCRIPTION (provided by applicant): In normal speech, adults fluidly utter 2 to 3 words per second selected from no less than 50,000 to 100,000 regularly-used words in the mental lexicon. Lexical selection is the process by which we access and fit an appropriate word to ongoing speech and is a core process for language production. Pathological disruption of lexical selection (i.e., anomia) is observed to some extent in all aphasic patients and can also be present in neurodegenerative diseases as well as normal aging. Despite the central importance of lexical selection to language and the immense personal and societal cost caused by its disruption, its neural basis and that involved in its recovery are poorly understood. Different regions of the prefrontal cortex (PFC) and of the left temporal cortex (LTC) have been associated with lexical selection but their precise role and the way they interact to enable lexica selection and compensation are still unknown. This lack of knowledge has both methodological and theoretical causes: (a) The brain imaging techniques generally used to study healthy speakers do not provide temporal information on the brain regions that are involved in lexical selection. Knowing when these different regions come online during lexical processing would confirm their different roles and would also suggest how they interact with each other to achieve lexical processing. (b) Language has typically been considered in isolation from other cognitive functions. A burgeoning body of evidence suggests that lexical selection is dependent on domain-general cognitive control mechanisms. If this is true, it would suggest that different brain regions play different linguistic and non-linguistic roles, a finding that would have significant ramifications for treatment and recovery of brain-injured patients. The goal of the proposed research is to test the hypotheses that: (1) Lexical selection is supported by top-down modulations from the left PFC onto the left LTC, similar to how non-linguistic action selection is controlled, and (2) The right PFC serves as a compensatory top-down mechanism for lexical selection when the left PFC is injured, similar to what has been shown outside of the language domain. To test these hypotheses, a combination of novel theoretical and methodological approaches will be used. First, the unique opportunity to record electrocorticography (ECoG) in neurosurgical patients will be used to determine which, when and how subregions of the PFC and the LTC are involved in lexical selection. Second, linguistic vs. domain-general contributions to lexical processing will be tested by directly comparing patients' performance on two tasks using the same stimuli, but differing only in the type of stimulus-response associations to be performed (linguistic vs. domain-general). Finally, these same tasks will be used with neurological patients recovering from stroke in either the left or right PFC in order to determine the effects of these injuries on lexical selection. Behavioral measurements as well as surface EEG signals will determine the relative roles of these regions in lexical selection, and whether the right PFC participates in compensating for the loss of top-down control when the left PFC is injured.

描述(申请人提供)：在正常语言中，成年人每秒流利地说出2到3个单词，从心理词典中不少于50,000到100,000个常用单词中选择。词汇选择是我们获取一个合适的词并将其匹配到正在进行的言语中的过程，是语言产生的核心过程。所有失语症患者都在一定程度上观察到词汇选择的病理性中断(即失语)，在神经退行性疾病和正常衰老中也可能存在。尽管词汇选择对语言至关重要，而且词汇选择的中断会给个人和社会带来巨大的代价，但人们对词汇选择的神经基础及其恢复过程知之甚少。前额叶皮质(PFC)和左侧颞叶皮质(LTC)的不同区域与词汇选择有关，但它们的确切作用及其相互作用使词汇选择和补偿的方式仍不清楚。这种知识的缺乏既有方法上的原因，也有理论上的原因：(A)通常用于研究健康说话者的大脑成像技术没有提供涉及词汇选择的大脑区域的时间信息。知道这些不同的区域在词汇处理过程中何时在线将确认它们的不同角色，也将提示它们如何相互作用以实现词汇处理。(B)通常将语言与其他认知功能分开考虑。越来越多的证据表明，词汇选择依赖于领域一般的认知控制机制。如果这是真的，那就说明不同的大脑 区域扮演着不同的语言和非语言角色，这一发现将对脑损伤患者的治疗和康复产生重大影响。本研究的目的是验证以下假设：(1)词汇选择是由从左PFC到左LTC的自上而下的调制支持的，类似于非语言行为选择的控制方式；(2)当左PFC受损时，右PFC作为一种自上而下的补偿机制来进行词汇选择，类似于语言领域外的研究。为了检验这些假设，将使用新颖的理论和方法相结合的方法。首先，在神经外科患者中记录皮层脑电(ECoG)的独特机会将被用来确定PFC和LTC的哪些亚区、何时以及如何参与词汇选择。其次，语言和领域对词汇加工的贡献将通过直接比较患者在使用相同刺激的两项任务中的表现来测试，但不同的只是要执行的刺激-反应关联的类型(语言和领域-一般)。最后，为了确定这些损伤对词汇选择的影响，这些相同的任务将被用于左侧或右侧PFC中中风康复的神经科患者。行为测量和表面脑电信号将决定这些区域在词汇选择中的相对作用，以及当左侧PFC受损时，右侧PFC是否参与补偿自上而下控制的丧失。