...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Progress in brain research >High-frequency gamma oscillations and human brain mapping with electrocorticography.
【24h】

High-frequency gamma oscillations and human brain mapping with electrocorticography.

机译：高频伽马振荡和脑皮层描记术

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Invasive EEG recordings with depth and/or subdural electrodes are occasionally necessary for the surgical management of patients with epilepsy refractory to medications. In addition to their vital clinical utility, electrocorticographic (ECoG) recordings provide an unprecedented opportunity to study the electrophysiological correlates of functional brain activation in greater detail than non-invasive recordings. The proximity of ECoG electrodes to the cortical sources of EEG activity enhances their spatial resolution, as well as their sensitivity and signal-to-noise ratio, particularly for high-frequency EEG activity. ECoG recordings have, therefore, been used to study the event-related dynamics of brain oscillations in a variety of frequency ranges, and in a variety of functional-neuroanatomic systems, including somatosensory and somatomotor systems, visual and auditory perceptual systems, and cortical networks responsible for language. These ECoG studies have confirmed and extended the original non-invasive observations of ERD/ERS phenomena in lower frequencies, and have discovered novel event-related responses in gamma frequencies higher than those previously observed in non-invasive recordings. In particular, broadband event-related gamma responses greater than 60 Hz, extending up to approximately 200 Hz, have been observed in a variety of functional brain systems. The observation of these "high gamma" responses requires a recording system with an adequate sampling rate and dynamic range (we use 1000 Hz at 16-bit A/D resolution) and is facilitated by event-related time-frequency analyses of the recorded signals. The functional response properties of high-gamma activity are distinct from those of ERD/ERS phenomena in lower frequencies. In particular, the timing and spatial localization of high-gamma ERS often appear to be more specific to the putative timing and localization of functional brain activation than alpha or beta ERD/ERS. These findings are consistent with the proposed role of synchronized gamma oscillations in models of neural computation, which have in turn been inspired by observations of gamma activity in animal preparations, albeit at somewhat lower frequencies. Although ECoG recordings cannot directly measure the synchronization of action potentials among assemblies of neurons, they may demonstrate event-related interactions between gamma oscillations in macroscopic local field potentials (LFP) generated by different large-scale populations of neurons engaged by the same functional task. Indeed, preliminary studies suggest that such interactions do occur in gamma frequencies, including high-gamma frequencies, at latencies consistent with the timing of task performance. The neuronal mechanisms underlying high-gamma activity and its unique response properties in humans are still largely unknown, but their investigation through invasive methods is expected to facilitate and expand their potential clinical and research applications, including functional brain mapping, brain-computer interfaces, and neurophysiological studies of human cognition.
机译：具有深度和/或硬脑膜下电极的有创脑电图记录有时对于药物难治性癫痫患者的手术治疗是必要的。除其至关重要的临床用途外，脑电记录（ECoG）记录提供了前所未有的机会来研究功能性脑部激活的电生理相关性，而不是非侵入性记录。 ECoG电极靠近脑电活动的皮质源可增强其空间分辨率，以及其灵敏度和信噪比，特别是对于高频脑电活动。因此，ECoG记录已用于研究各种频率范围内以及各种功能性神经解剖系统（包括体感和体动系统，视觉和听觉感知系统以及皮层网络）中与事件有关的大脑振荡的动力学。负责语言。这些ECoG研究已经证实并扩展了较低频率ERD / ERS现象的原始非侵入性观察，并发现了伽马频率中新的与事件相关的响应，该响应高于先前在非侵入性记录中观察到的响应。尤其是，在各种功能性大脑系统中都观察到宽带事件相关的伽玛响应大于60 Hz，扩展到大约200 Hz。要观察这些“高伽马”响应，需要具有适当采样率和动态范围的记录系统（我们在16位A / D分辨率下使用1000 Hz），并且通过对记录信号进行事件相关的时频分析来简化这些记录。高伽玛活动的功能响应特性与低频下的ERD / ERS现象不同。尤其是，与α或βERD / ERS相比，高伽玛ERS的时机和空间定位通常似乎更特定于功能性大脑激活的假定时机和定位。这些发现与拟议的同步伽马振荡在神经计算模型中的作用相一致，反过来又受到动物制剂中伽马活性观察结果的启发，尽管频率较低。尽管ECoG记录无法直接测量神经元组件之间动作电位的同步，但它们可能会证明由同一功能任务参与的不同规模的神经元群体产生的宏观局部场电位（LFP）中的伽马振荡之间的事件相关相互作用。确实，初步研究表明，这种交互作用确实会在伽马频率（包括高伽马频率）中发生，并与任务执行的时间一致。高伽玛活性及其在人类中的独特反应特性所基于的神经元机制仍是未知之数，但通过侵入性方法进行的研究有望促进和扩展其潜在的临床和研究应用，包括功能性脑图，脑机接口和人类认知的神经生理学研究。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号