Cortical spatiotemporal plasticity in humans

描述（由申请人提供）：本申请的总体目标是描述人类皮层可塑性的规则，通过基于MEG/EEG的成像进行分析，与听觉感知学习相关。破译的规则支配皮层可塑性和知觉学习是重要的训练协议的发展，旨在改善听觉，这是在很大比例的个人与学习障碍，阅读障碍，老化或其他认知障碍受损。目前建议的概念理论框架是基于感知学习的反向层次理论（RHT）。这一理论已经成功地统一了视觉知觉学习的几个行为，解剖和生理发现。我们已经适应了RHT听觉知觉学习，并得出了一系列的时空皮层可塑性和行为改善的特点可检验的假设。RHT断言学习是一个自上而下的引导过程，它从听觉处理层次的高级区域开始，并沿着该层次向后沿着前进到较早的输入级别，以便在成功执行所需的层次中的适当级别上增加信号表示。在这里，我们测试的三个任务，样本三个基本过程沿着听觉处理层次的上下文中的几个预测从RHT。这些任务是简单和复杂的音调序列的调制速率鉴别（R）和频率鉴别（F），以评估时间、频谱和会聚频谱时间信息处理。第一个具体的目的是检查学习的速度和特异性引起的简短和广泛的培训协议。第二个具体的目的是研究学习诱导的可塑性的特点，MEG/EEG为基础的成像分析。第三个具体目标是研究刺激的可变性和心理物理任务条件对皮层可塑性和学习特征的影响。我们的方法是联合收割机的心理声学研究来分析听觉感知学习与新的时空源定位方法从MEG/EEG数据。通过比较行为改善与皮层可塑性的特征，我们提出了解开与听觉知觉学习相关的皮层时空可塑性的一般规则。

DESCRIPTION (provided by applicant): The overall goal of this application is to delineate the rules of human cortical plasticity, assayed by MEG/EEG based imaging, associated with auditory perceptual learning. Deciphering the rules governing cortical plasticity and perceptual learning is important for the development of training protocols aimed at improving auditory perception, which is impaired in a large proportion of individuals with learning-disability, reading-impairment, aging or other cognitive impairments. The conceptual theoretical framework of the current proposal is based on the Reverse Hierarchy Theory of Perceptual Learning (RHT). This theory has been successful in unifying several behavioral, anatomical and physiological findings of visual perceptual learning. We have adapted RHT for auditory perceptual learning and derived a series of testable hypotheses for spatiotemporal cortical plasticity and for the characteristics of behavioral improvement. RHT asserts that learning is a top-down guided process, which begins at high-level areas of the auditory processing hierarchy and progresses backwards along this hierarchy to earlier input levels so as to increase signal representation at the appropriate level in the hierarchy that is required for successful performance. Here, we test several predictions from RHT in the context of three tasks that sample three fundamental processes along the auditory processing hierarchy. These tasks are modulation-rate discrimination (R) and frequency discrimination (F) of simple and complex tone-trains to assess temporal, spectral and convergent spectrotemporal information processing. The first specific aim is to examine the rate and specificity of learning induced by brief and by extensive training protocols. The second specific aim is to examine characteristics of learning-induced plasticity, assayed by MEG/EEG based imaging. The third specific aim is to examine the effects of stimulus variability and psychophysical task conditions on cortical plasticity and learning characteristics. Our approach is to combine psychoacoustic studies to assay auditory perceptual learning with novel spatiotemporal source localization methods from MEG/EEG data. By comparing characteristics of behavioral improvements with cortical plasticity we propose to unravel general rules of cortical spatiotemporal plasticity associated with auditory perceptual learning.