HUMAN MIDDLE LATENCY AUDITORY EVOKED POTENTIALS

中潜伏期听觉诱发电位（MAEP，潜伏期10-70 msec） 提供了与脑电活动相关的电活动的直接测量。 人类对声音的短潜伏期丘脑和皮层分析。然而，在这方面， 尽管临床使用越来越多，但对它们的大多数用途知之甚少。 基本属性。例如，皮层和皮层下 参与MAEP生成的结构仍然存在争议， 不确定它们是如何组织的：它们是否具有音调拓扑和/或空间拓扑 像听觉结构一样的组织 我们将在五个实验中解决这些基本问题。两项新技术 将纳入所有研究。首先，我们将详细记录头皮 32个电极的形貌和提取拉普拉斯MAEP（LAP-MAEP） 在时间地点上。LAP-MAEP增强了MAEP对焦点的分辨率 听觉皮层的发电机其次，我们将关联MAEP分布 测量候选MAEP发生器的相对方位 直接从高分辨率核磁共振扫描中获取。我们将使用这些改进的 技术来研究组织的MAEP发电机处理 强度（实验I）、频率（实验II）和空间位置 （实验三）听觉信号。 关于MAEP发生器的假设将在两个实验中得到进一步验证 充分利用我们的临床人群。在 在实验IV中，我们将记录局灶性病变患者组的MAEP， 候选MAEP发生器，包括上级时间平面和 听觉皮层，背外侧额叶皮层，顶叶下， 后丘脑和基底神经节。在实验五中，我们将比较 接受手术的患者头皮和皮质表面的MAEP 开颅手术在正常人和病人身上的实验形成了一个 全面的序列，将提供更好的理解 对人脑中的声音进行短潜伏期分析，并增强 MAEP在神经学和神经外科应用中的临床效用。

Middle latency auditory evoked potential (MAEPs, latencies 10-70 msec) provide a direct measure of the electrical activity associated with the short-latency thalamic and cortical analysis of sounds in humans. However, despite increasing clinical use little is known about their most fundamental properties. For example, the cortical and subcortical structures involved in MAEP generation remain in dispute, and it is uncertain how they are organized: do they have tonotopic and/or spatiotopic organizations like auditory structures in many species? We will address these basic issues in five experiments. Two new techniques will be incorporated in all studies. First, we will record detailed scalp topographies from 32 electrodes and extract Laplacean MAEPs (LAP-MAEPs) over temporal sites. LAP-MAEPs enhance the resolution of MAEPs to focal generators in auditory cortex. Second, we will correlate MAEP distributions with the relative orientations of candidate MAEP generators measured directly from high-resolution MRI scans. We will use these improved techniques to study the organization of MAEP generators for processing the intensity (Experiment I), frequency (Experiment II), and spatial position (Experiment III) of auditory signals. Hypotheses about MAEP generators will be further tested in two experiments that take advantage of our well-delineated clinical populations. In Experiment IV, we will record MAEPs in patient groups with focal lesions of candidate MAEP generators, including the superior temporal plane and auditory cortex, dorsolateral frontal cortex, inferior parietal lobe, the posterior thalamus and basal ganglia. In Experiment V, we will compare MAEPs from the scalp and cortical surface in patient undergoing craniotomies. The experiments in normal subjects and patients form a comprehensive sequence that will provide a better understanding of the shortlatency analysis of sounds in the human brain, and enhance the clinical utility of MAEPs in neurological and neurosurgical applications.