Visual grouping and the focusing of attention induce gamma-band oscillations at different frequencies in human magnetoencephalogram signals
Visual grouping and the focusing of attention induce gamma-band oscillations at different frequencies in human magnetoencephalogram signals
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DOI：
10.1162/jocn.2006.18.11.1850
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发表时间：
2006-11-01
影响因子：
3.2
通讯作者：
Tallon-Baudry, Catherine
中科院分区：
文献类型：
--
作者：
Vidal, Juan R.;Chaumon, Maximilien;Tallon-Baudry, Catherine
神经振荡同步可以实现分组过程，起到注意过滤器的作用，或促进短期记忆中的信息存储。这些发现是否表明振荡同步是发生在任何苛刻任务中的一种非特异性附带现象，或者振荡同步是每当要求神经合作时所涉及的基本机制？如果后一种假设是正确的，那么振荡同步应该是特定的，不同的视觉过程引发不同类型的振荡。我们一边记录脑磁图（MEG）信号，一边操纵视觉显示的分组特性，另一方面集中注意力以记忆该显示的部分内容。分组相关的伽马振荡在所有条件下都存在，但在枕部中心位置的高伽马波段（70120 Hz）受到刺激的分组特性（一组或两组）的调制。当在顶叶位置的低伽马波段（44-66 Hz）要求注意聚焦时，与注意相关的伽马振荡就会作为一个额外的成分出现。因此，我们的结果揭示了伽马范围内功能专门化的存在，与分组相关的振荡出现的频率高于与注意力相关的振荡。因此，振荡同步的模式是与之相关的视觉过程的特定模式。我们的研究结果进一步表明，分组过程和集中注意力都依赖于一个共同的实现过程，即伽马波段振荡同步，这一发现可以解释连贯的感知比不连贯的感知更容易引起注意的事实。
Neural oscillatory synchrony Could implement grouping processes, act as an attentional filter, or foster the storage of information in short-term memory. Do these findings indicate that oscillatory synchrony is an unspecific epiphenomenon occurring in any demanding task, or that oscillatory synchrony is a fundamental mechanism involved whenever neural cooperation is requested? If the latter hypothesis is true, then oscillatory synchrony should be specific, with distinct visual processes eliciting different types of oscillations. We recorded magneto-encephalogram (MEG) signals while manipulating the grouping properties of a visual display on the one hand, and the focusing of attention to memorize part of this display on the other hand. Grouping-related gamma oscillations were present in all conditions but modulated by the grouping properties of the stimulus (one or two groups) in the high gamma-band (70120 Hz) at central occipital locations. Attention-related gamma oscillations appeared as an additional component whenever attentional focusing was requested in the low gamma-band (44-66 Hz) at parietal locations. Our results thus reveal the existence of a functional specialization in the gamma range, with grouping-related oscillations showing up at higher frequencies than attention-related oscillations. The pattern of oscillatory synchrony is thus Specific Of the Visual process it is associated With. Our results further suggest that both grouping processes and focused attention rely on a common implementation process, namely, gamma-band oscillatory synchrony, a finding that Could account for the fact that coherent percepts are more likely to catch attention than incoherent ones.