Cortical spatiotemporal plasticity in humans

描述（由申请人提供）：了解 人类学习的复杂性和相关的大脑功能是最重要的 基础科学的奇妙旅程除了是一个重要的 学术问题，与学习相关的大脑功能研究 改善学习诊断和治疗的实际应用 残疾。学习障碍影响着10%到20%的美国人 对他们的生活质量和健康造成严重的社会经济后果。 这项建议的重点是了解神经过程的基础正常 人类对听觉信息的学习是短暂的， 传承为这种处理的最直观的例子反映在我们的 学习和理解演讲的能力。学习这种形式的缺陷 信息与阅读障碍和语言学习障碍有关。 一些目前流行的工具，用于研究之间的关系， 人类学习和相关的大脑过程是正电子发射断层扫描 (PET)功能性磁共振成像（fMRI），脑磁图 (MEG)脑电图（EEG）。然而，在所有这些方法中，只有MEG 和EEG提供了足够的时间分辨率，这对拟议的研究至关重要 因为大脑对听觉刺激的反应通常发生在时间尺度上， 毫秒。使用MEG和EEG获得的数据通常被分析， 考虑到皮质活动的动力学和经常简化的来源， 和头部模型假设，获得有关大脑可塑性的信息， 这种时尚很难理解和解释。最近几种新方法 已经被开发来处理脑磁图和脑电图数据。然而， 这些方法还没有在真实的数据上得到充分的证明。 该提案的第一个具体目标是研究和验证新的 分析方法，将提高脑电图和脑磁图数据的解释。我们 将使用逼真的头部建模来成像分布式源和帐户 大脑活动的时空动态我们将凭经验 验证这些方法的有用性，以了解动态的 功能性大脑可塑性的计算机模拟和实验。的 该提案的第二个具体目标是确定 功能性脑可塑性的时空反应动力学 连续的刺激和心理物理阈值的变化， 知觉学习的结果。我们将专注于学习率歧视 在正常成年人中进行调幅音调训练， 理解学习简单的时变听觉刺激，发生在 快速的继承我们将研究学习诱发的行为 随着活动的空间和时间模式的变化而变化 在皮层区域内部和之间。 这种多学科方法结合了科学方法， 使用MEG和EEG的计算和功能性脑成像应该可以增强我们的 理解人类感知的一般神经机制 学习这些结果在正常人应该提供关键 用于诊断、完善和评估的信息， 治疗有学习障碍的人。

DESCRIPTION (Provided by Applicant): Understanding the relationship between the complexity of human learning and associated brain function is one of the most fascinafing journeys of basic science. In addition to being an important academic question, studies of brain function assocIated with learning have very practical applications for improving diagnosis and therapy of learning disabilities. Learning disability affects between 10-20 percent of Americans with severe socioeconomic consequences on their quality of life and health. This proposal focuses on understanding the neural processes underlying normal human learning of auditory information that is transient and occurs in rapid succession. The most intuitive example of such processing is reflected in our ability to learn and understand speech. Deficits in learning such forms of information are associated with dyslexia and language-learning impairment. A few of the currently popular tools used to study the relationships between human learning and associated brain processes are Positron Emission Tomography (PET), Functional Magnetic Resonance Imaging (fMRI), Magnetoencephalography (MEG) and Electroencephalography (EEG). However, of all these methods only MEG and EEG offer adequate time resolution, essential for the proposed study because brain responses to auditory stimuli typically occur in the time-scale of milliseconds. Data obtained using MEG and EEG is often analyzed without consideration of the dynamics of cortical activity and often simplified source and head models are assumed, Information about brain plasticity obtained in this fashion is hard to understand and interpret. Recently several new methods have been developed to process MEG and EEG data. However, the usefulness of these methods has not been adequately demonstrated on real data. The first specific aim of this proposal is to research and to validate novel analyses methods that will enhance the interpretation of EEG and MEG data. We will use realistic head modeling for imaging distributed sources and account for the spatio-temporal dynamics of brain activity. We will empirically validate the usefulness of these methods to understand the dynamics of functional brain plasticity using computer simulations and experiments. The second specific aim of the proposal is to determine the relationship between the dynamics of functional brain plasticity in spatio-temporal responses to successive stimuli and changes in psychophysical thresholds that occur as a result of perceptual learning. We will focus on learning in rate discrimination of amplitude-modulated tone trains in normal adults as a first step towards understanding learning of simple time-varying auditory stimuli that occur in rapid succession. We will examine and correlate learning-induced behavioral changes with changes in the spatial and the temporal patterns of activity within and across cortical areas. Such a multidisciplinary approach which combines methods of scientific computing and functional brain imaging using MEG and EEG should enhance our understanding of general neural mechanisms underlying human perception learning. These results in normal individuals should provide crucial information for the development, refinement and evaluation of diagnosis and therapy for individuals with learning disability.