Electrocorticographic studies of human cortical function

描述（改编自申请人的摘要）： 拟议的研究是识别和验证电生理特征， 人类大脑皮层的处理，并利用它们来研究神经机制， 运动、感觉和语言功能。以前的EEG和MEG研究 将区域皮质激活与事件相关的能量变化联系起来， α（8-13 Hz）和γ（40 Hz）振荡。使用皮层电图 （ECoG）记录从硬膜下电极植入用于临床目的，我们 证实了这些观测结果，并发现了一个与事件有关的宽带 高伽马频率（80-100 Hz）下的功率增强。这个新的索引 功能皮层激活在空间和时间上更分散， 更符合功能解剖学和神经生理学（ERP） 与先前描述的光谱变化相关。伽马振荡具有 与皮层神经元组装的同步有关， 处理.相反，α振荡的抑制被认为是 从丘脑皮层回路的激活中， 处理.因此，我们建议测试以下假设：（1）， 宽带“高”伽马ERS指示特定任务的皮层处理， (2)α去核化通过丘脑皮质促进这种处理 电路.我们的具体目标是测试（A）空间和（B） 皮层激活的这些光谱指数之间的时间对应性 以及以下基准：（i）功能解剖学的一般知识 知觉，运动和语言任务，（ii）特定的功能解剖 从用于临床目的的皮层刺激映射导出的信息， (iii)感知刺激和运动反应的潜伏期和持续时间，以及 (iv)事件相关电位的时空特性的 我们从这些ECoG研究中得出的结论的普遍性将在一个 正常人组采用高密度头皮脑电图。导出的信息 这项研究将促进未来的神经生理学研究， 人类大脑激活的相关性，包括对时间的研究， 正常和紊乱的认知/神经元操作的地形图。

DESCRIPTION(adapted from applicant's abstract): The overall objective of the proposed research is to identify and validate electrophysiological signatures of human cortical processing and to use them to study the neural mechanisms of motor, sensory, arid language functions. Previous EEG and MEG studies have linked regional cortical activation with event-related changes in the energy of alpha (8-13 Hz) and gamma (40 Hz) oscillations. Using electrocorticographic (ECoG) recordings from subdural electrodes implanted for clinical purposes, we have confirmed these observations and discovered an event-related broad-band augmentation of power in high gamma frequencies (80-100 Hz). This novel index of function cortical activation is more discretely localized in space and time, and more consistent with functional-anatomic and neurophysiological (ERP) correlates, than previously described spectral changes. Gamma oscillations have been associated with the synchronization of neuronal assemblies during cortical processing. In contrast, suppression of alpha oscillations is thought to arise from the activation of thalamocortical circuits that otherwise gate cortical processing. We therefore propose to test the following hypotheses: (1) that broad-band "high" gamma ERS indexes task-specific cortical processing, and that (2) alpha desynchronization facilitates this processing via thalamocortical circuits. Our specific aims are directed toward testing the (A) spatial and (B) temporal correspondence between these spectral indices of cortical activation and the following benchmarks: (i) general knowledge of the functional anatomy of perceptual, motor, and language tasks, (ii) specific functional-anatomic information derived from cortical stimulation mapping for clinical purposes, (iii) the latency and duration of perceptual stimuli and motor responses, and (iv) spatiotemporal properties of event-related potentials. The generalizability of our conclusions from these ECoG studies will be tested in a group of normal subjects using high density scalp EEG. Information derived from this research will facilitate future investigations of the neurophysiological correlates of human brain activation, including studies of the timing and topography of normal and disordered cognitive/neuronal operations.