Sources of synchronized induced Gamma-Band responses during a simple object recognition task:: A replication study in human MEG
Sources of synchronized induced Gamma-Band responses during a simple object recognition task:: A replication study in human MEG
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DOI：
10.1016/j.brainres.2007.12.037
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发表时间：
2008-02-27
期刊：
影响因子：
2.9
通讯作者：
Mueller, M. M.
中科院分区：
文献类型：
--
作者：
Gruber, T.;Maess, B.;Mueller, M. M.
自然刺激是由许多特征组成的，这些特征在皮层上以分散的结构表示。伽马波段的同步振荡（> 30 Hz;诱发伽马波段反应，iGBR）被认为是将这些区域重新整合为有意义的皮质对象表征的合理机制。使用脑电图（EEG）证明，iGBR的发生器可以定位于颞叶、顶叶、后部和额叶区域。目前的脑磁图（MEG）研究旨在复制这些发现，以促进正在进行的辩论有关的可能的功能差异的高频信号测量的两种技术。在一个标准的物体识别任务中，我们发现在刺激开始后160-440 ms，有意义的刺激与无意义的刺激相比，iGBR会增加。该峰位于颞下回、上级顶叶和右侧额中回。重要的是，这些大脑结构中的大多数都是相互锁定的。这些结果的意义是双重的：（1）它们为iGBR表示在物体识别期间广泛分布的网络中的神经元活动的观点提供了进一步的证据。(2)MEG非常适合检测与EEG记录显示的形态非常相似的诱导高频振荡，从而消除了脑电图方法的已知问题（例如参考混淆）。与iGBR相反，事件相关场（ERFs）和诱发的伽马波段反应（eGBR）的定位揭示了焦点视觉区的发生器，因此，似乎反映了早期的感觉处理。(C)2007 Elsevier B. V.保留所有权利。
Natural stimuli are compiled of numerous features, which are cortically represented in dispersed structures. Synchronized oscillations in the Gamma-Band (>30Hz; induced Gamma-Band Responses, iGBRs), are regarded as a plausible mechanism to re-integrate these regions into a meaningful cortical object representation. Using electroencephalography (EEG) it was demonstrated that the generators of iGBRs can be localized to temporal, parietal, posterior, and frontal areas. The present magnetoencephalogram (MEG) study intended to replicate these findings in order contribute to the ongoing debate regarding the possible functional difference of high-frequency signals as measured by both techniques. During a standard object recognition task we found an augmentation of the iGBR after the presentation of meaningful as opposed to meaningless stimuli at similar to 160-440 ms after stimulus onset. This peak was localized to inferior temporal gyri, superior parietal lobules and the right middle frontal gyrus. Importantly, most of these brain structures were significantly phase-locked to each other. The implications of these results are twofold: (1) they present further evidence for the view that iGBRs signify neuronal activity in a broadly distributed network during object recognition. (2) MEG is well suited to detect induced high-frequency oscillations with a very similar morphology as revealed by EEG recordings, thereby eliminating known problems with electroencephalographical methods (e.g. reference confounds). In contrast to the iGBR, the localization of event-related fields (ERFs) and evoked Gamma-Band Response (eGBRs) revealed generators in focal visual areas, and thus, seem to mirror early sensory processing. (C) 2007 Elsevier B.V. All rights reserved.