Cracking the code of oscillatory activity.
Cracking the code of oscillatory activity.
复制标题
DOI：
10.1371/journal.pbio.1001064
复制
发表时间：
2011-05
期刊：
影响因子：
9.8
通讯作者：
Gross J
中科院分区：
文献类型：
--
作者：
Schyns PG;Thut G;Gross J
神经振荡是认知过程和信息动态路由和门控的普遍测量。神经科学迄今为止尚未解决的基本问题仍然是了解大脑中的振荡活动如何编码人类认知的信息。在一项生物学相关的认知任务中，我们指导六名人类观察者对情绪的面部表情进行分类，同时测量观察者的脑电图。我们将最先进的刺激控制与统计信息理论分析相结合，以量化振荡的三个参数（即功率、相位和频率）如何编码与认知任务中的行为相关的视觉信息。我们提出三点：首先，我们证明相位编码的与认知任务相关的信息比功率多得多（2.4倍）。其次，我们证明功率和相位编码的结合反映了与行为反应相关的详细视觉特征，即由行为预测的面部表情特征。第三，我们证明，与通信技术类似，大脑中的振荡频率可以复用视觉特征的编码，从而提高编码能力。总之，我们关于神经振荡基本编码特性的发现将通过确定频率、相位和幅度在大脑中编码行为相关信息中的不同作用来重新调整神经科学的研究议程。为了快速识别视觉信息，大脑必须连续编码撞击视网膜的复杂、高维信息，并非所有信息都是相关的，因为低维编码足以满足识别和行为的需求（例如，只有睁大眼睛才能正确识别恐惧的表情）。大脑的振荡网络动态地将高维信息减少为低维代码，但仍不清楚这些振荡的哪些方面产生低维代码。在这里，我们测量了人类观察者的脑电图，同时向他们提供了表情面部（快乐、悲伤、恐惧等）的视觉信息样本。利用统计信息理论，我们提取了对于正确识别每个表情（例如，张开嘴表示“快乐”，睁大眼睛表示“恐惧”）信息最丰富的低维代码。接下来，我们测量了大脑振荡的三个参数（频率、功率和相位）如何编码低维特征。令人惊讶的是，我们发现相位编码的任务信息是功率的 2.4 倍。我们还表明，功率和相位的结合足以编码整个大脑振荡的低维面部特征。这些发现提供了一种新的方式来思考频率、相位和幅度在大脑中编码行为相关信息中的不同作用。
Neural oscillations are ubiquitous measurements of cognitive processes and dynamic routing and gating of information. The fundamental and so far unresolved problem for neuroscience remains to understand how oscillatory activity in the brain codes information for human cognition. In a biologically relevant cognitive task, we instructed six human observers to categorize facial expressions of emotion while we measured the observers' EEG. We combined state-of-the-art stimulus control with statistical information theory analysis to quantify how the three parameters of oscillations (i.e., power, phase, and frequency) code the visual information relevant for behavior in a cognitive task. We make three points: First, we demonstrate that phase codes considerably more information (2.4 times) relating to the cognitive task than power. Second, we show that the conjunction of power and phase coding reflects detailed visual features relevant for behavioral response—that is, features of facial expressions predicted by behavior. Third, we demonstrate, in analogy to communication technology, that oscillatory frequencies in the brain multiplex the coding of visual features, increasing coding capacity. Together, our findings about the fundamental coding properties of neural oscillations will redirect the research agenda in neuroscience by establishing the differential role of frequency, phase, and amplitude in coding behaviorally relevant information in the brain. To recognize visual information rapidly, the brain must continuously code complex, high-dimensional information impinging on the retina, not all of which is relevant, because a low-dimensional code can be sufficient for both recognition and behavior (e.g. a fearful expression can be correctly recognized only from the wide-opened eyes). The oscillatory networks of the brain dynamically reduce the high-dimensional information into a low dimensional code, but it remains unclear which aspects of these oscillations produce the low dimensional code. Here, we measured the EEG of human observers while we presented them with samples of visual information from expressive faces (happy, sad, fear, etc.). Using statistical information theory, we extracted the low-dimensional code that is most informative for correct recognition of each expression (e.g. the opened mouth for “happy,” the wide opened eyes for “fear”). Next, we measured how the three parameters of brain oscillations (frequency, power and phase) code for low-dimensional features. Surprisingly, we find that phase codes 2.4 times more task information than power. We also show that the conjunction of power and phase sufficiently codes the low-dimensional facial features across brain oscillations. These findings offer a new way of thinking about the differential role of frequency, phase and amplitude in coding behaviorally relevant information in the brain.
登录
查看更多内容
影响因子：
2.4
作者：
Magri C;Whittingstall K;Singh V;Logothetis NK;Panzeri S
通讯作者：
Panzeri S
影响因子：
1.8
作者：
Gosselin, F;Schyns, PG
通讯作者：
Schyns, PG
影响因子：
--
作者：
SHANNON, CE
通讯作者：
SHANNON, CE
DOI：
10.1073/pnas.0508972103
发表时间：
2006-04-04
影响因子：
11.1
作者：
Smith, ML;Gosselin, F;Schyns, PG
通讯作者：
Schyns, PG
影响因子：
5.7
作者：
Hanslmayr, Simon;Aslan, Alp;Baeuml, Karl-Heinz
通讯作者：
Baeuml, Karl-Heinz