Neural mechanisms: Learned audio-visuo-motor integration

神经机制：习得的视听运动整合

• 批准号: 7033274
• 负责人: JOHN W BELLIVEAU
• 金额: $ 71.54万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7033274
• 关键词: association learning; behavioral /social science research tag; bioimaging /biomedical imaging; brain electrical activity; brain imaging /visualization /scanning; brain mapping; clinical research; computational neuroscience; functional magnetic resonance imaging; human subject; magnetoencephalography; memory; neural information processing; neuropsychology; nonEnglish language; psychomotor function; psychophysiology; sound perception; speech; verbal behavior; visual perception

DESCRIPTION (provided by applicant): This study answers fundamental questions of large-scale neural networks in the human brain supporting crossmodal cognition. To reveal how auditory and visual stimuli and motor acts are arbitrarily combined as a result of crossmodal learning and integrated to supramodal symbolic representations, we will study the neural representations of the letters of the Roman alphabet. These consist of four unimodal representations (visual, auditory, and motor representations for writing and speaking) and learned connections between these, that is, the processes that underlie their audiovisual recognition and motor production. Accurate experimental control is facilitated by the fact that letters exhibit all the necessary properties of symbolic crossmodal representations but in a physically simple and exact format carrying no semantic associations that could confound the neurophysiological interpretation of results. Combined 3-Tesla functional magnetic resonance imaging (fMRI) and 306-channel magnetoencephalographic / 128-channel electroencephalographic (MEG/EEG) techniques with simultaneous behavioral recordings will be applied to pinpoint the exact underlying neural mechanisms. This approach combines the advantages of spatially accurate fMRI with temporally specific MEG/EEG, enabling accurate spatiotemporal characterization of brain activity totally noninvasively. To directly observe how large-scale neurocognitive networks evolve during crossmodal associative learning, we will also conduct fMRI/MEG/EEG measurements before and after our subjects are taught (previously unfamiliar) Japanese kana-letters. The specific aims are to elucidate structure, function, and oscillatory mechanisms of fully established crossmodal neural networks based on previous extensive associative learning (Roman letters) and currently evolving networks representing novel crossmodal associations (Japanese letters). We will characterize the relative roles of deep brain nuclei, cerebellum, medial temporal lobe, and sensory-specific and multisensory association cortices in such networks. The multidimensional experimental design allows isolation of neural mechanisms utilized by perception, working memory, memory encoding, and recall.

描述（由申请人提供）：这项研究回答了人脑中支持跨模态认知的大规模神经网络的基本问题。为了揭示听觉和视觉刺激以及运动行为如何由于跨模态学习而任意组合并整合到超模态符号表征中，我们将研究罗马字母的神经表征。这些由四种单模态表征（用于书写和口语的视觉、听觉和运动表征）以及这些表征之间的习得联系组成，即视听识别和运动产生的过程。字母表现出符号跨模态表示的所有必要属性，但其物理上简单且精确的格式不携带可能混淆结果的神经生理学解释的语义关联，这一事实促进了准确的实验控制。结合 3 特斯拉功能磁共振成像 (fMRI) 和 306 通道脑磁图/128 通道脑电图 (MEG/EEG) 技术以及同步行为记录，将用于查明确切的潜在神经机制。这种方法结合了空间精确的 fMRI 与时间特定的 MEG/EEG 的优点，能够完全无创地准确描述大脑活动的时空特征。为了直接观察大规模神经认知网络在跨模式联想学习过程中如何演变，我们还将在我们的受试者教授（以前不熟悉的）日语假名字母之前和之后进行功能磁共振成像/脑磁图/脑电图测量。具体目标是阐明基于先前广泛的联想学习（罗马字母）和当前代表新颖跨模态关联（日语字母）的不断发展的网络的完全建立的跨模态神经网络的结构、功能和振荡机制。我们将描述深部脑核、小脑、内侧颞叶以及感觉特异性和多感觉关联皮层在此类网络中的相对作用。多维实验设计允许分离感知、工作记忆、记忆编码和回忆所利用的神经机制。