A MEG Study of Saccardic Eye Movement Effects on Word Processing

眼跳眼动对文字处理影响的脑磁图研究

• 批准号: 7145501
• 负责人: SIMONA TEMEREANCA IBANESCU
• 金额: $ 8.75万
• 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: 2006-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7145501
• 关键词: attention; behavior test; bioimaging /biomedical imaging; biophysics; brain imaging /visualization /scanning; clinical research; cognition; electroencephalography; fovea centralis retinae; human subject; interview; language; magnetic resonance imaging; magnetoencephalography; neural information processing; psychophysics; reading; saccades; time resolved data; visual perception; visual stimulus; vocabulary

DESCRIPTION (provided by applicant): Saccades are rapid eye movements employed during active vision to bring the target of interest onto the fovea, the retinal area of highest visual acuity. They are critical to essential human behaviors such as reading and visual exploration of the environment, with recent perceptual studies emphasizing their active role in regulating the flow of visual information. The impact of saccades on word recognition remains little understood, however, because most studies have focused on static visual processing wherein visual stimuli are presented during constant fixation. The aim of this research proposal is to investigate the spatial temporal dynamics of brain activity as words are processed following saccades, using a multimodal imaging approach that combines whole-head magnetoencephalography (MEG), electroencephalography (EEG), anatomical magnetic resonance imaging (MRI), and psychophysical methods. Integrating MEG/EEG with MRI provides a powerful tool for human brain imaging by allowing source localization of the magnetic and electrical signal on a millimeter spatial scale, with the high temporal resolution (milliseconds) inherent to MEG/EEG recordings. Our working hypothesis is that word processing is facilitated within a narrow time window following an eye movement and we aim to uncover the neuronal mechanisms involved. To distinguish between different postsaccadic effects (visual, motor, and attentional influences), we will compare the brain activations to words presented following saccades vs. externally generated image motion that mimics that during an eye movement. Word frequency and repetition priming effects within a lexical decision task will be used to investigate postsaccadic effects on different aspects (visual feature, orthographic, phonological, semantic) of language processing. To our knowledge, this is the first study to investigate saccadic modulation of word processing using multimodal MEG/EEG/MRI recordings. This work will contribute to elucidating the neural processes underlying control of eye movements and attention, and will advance our understanding of how active vision influences brain activity and visual processing during reading. Furthermore, results are expected to have important implications for clinical research in dyslexia, attention-deficit hyperactivity disorder (ADHD) and schizophrenia, where eye-movements have been shown to be abnormal.

描述（由申请人提供）：扫视是主动视觉期间采用的快速眼球运动，用于将感兴趣的目标带到中央凹，即视力最高的视网膜区域。它们对于阅读和对环境的视觉探索等人类基本行为至关重要，最近的感知研究强调了它们在调节视觉信息流中的积极作用。然而，眼跳对单词识别的影响仍然知之甚少，因为大多数研究都集中在静态视觉处理上，其中视觉刺激是在持续注视期间呈现的。本研究提案的目的是利用结合了全头脑磁图 (MEG)、脑电图 (EEG) 和解剖磁共振成像 (MRI) 的多模态成像方法，研究扫视后处理单词时大脑活动的时空动态。和心理物理学方法。将 MEG/EEG 与 MRI 集成，通过允许在毫米空间尺度上对磁信号和电信号进行源定位，并具有 MEG/EEG 记录固有的高时间分辨率（毫秒），为人脑成像提供了强大的工具。我们的工作假设是，文字处理是在眼球运动后的狭窄时间窗口内进行的，我们的目标是揭示所涉及的神经元机制。为了区分不同的眼跳后效应（视觉、运动和注意力影响），我们将比较大脑激活与眼跳后呈现的单词与模仿眼球运动期间的外部生成的图像运动。词汇决策任务中的词频和重复启动效应将用于研究语言处理的不同方面（视觉特征、拼写、语音、语义）的后语效应。据我们所知，这是第一项使用多模态 MEG/EEG/MRI 记录来研究文字处理的扫视调制的研究。这项工作将有助于阐明控制眼球运动和注意力的神经过程，并将促进我们对主动视觉如何影响阅读过程中的大脑活动和视觉处理的理解。此外，研究结果预计将对阅读障碍、注意力缺陷多动障碍（ADHD）和精神分裂症的临床研究产生重要影响，这些疾病的眼球运动已被证明是异常的。