EEG phase patterns reflect the representation of semantic categories of objects
EEG phase patterns reflect the representation of semantic categories of objects
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DOI：
10.1007/s11517-015-1391-7
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发表时间：
2016-01-01
影响因子：
3.2
通讯作者：
Shekarchi, Babak
中科院分区：
文献类型：
--
作者：
Behroozi, Mehdi;Daliri, Mohammad Reza;Shekarchi, Babak
脑电信号的振荡反映了由行为任务和感觉表征引起的认知过程。以往的研究表明，事件相关的EEG和感觉认知表征之间的关系，并揭示了分类的呈现对象可以成功地识别使用记录的EEG信号时，受试者查看对象。在这里，EEG信号结合多元模式识别技术被用于调查的可能性，以确定概念表示的基础上提出的12个语义类别的对象（每类5个样本）。使用多变量刺激解码方法，令人惊讶的是，我们证明了如何区分对象的相位模式的EEG信号在整个时间在低频带（1-4 Hz），但不是从功率振荡的大脑信号在同一频带。相比之下，在高频带（20-30 Hz）中，从EEG信号的功率的辨别准确度显著高于从EEG信号的相位的辨别准确度。此外，我们的研究结果表明，预测的准确性如何在大脑的各个区域之间不断变化。特别是，我们发现，在物体分类任务，在低频带的试验间相位相干性显着高于其他频率在各个感兴趣的区域。该测量与跨时间的解码模式相关联。这些结果表明，概念表征的机制可以通过振荡神经活动的相位来介导。
Oscillations of electroencephalographic signals represent the cognitive processes arose from the behavioral task and sensory representations across the mental state activity. Previous studies have shown the relation between event-related EEG and sensory-cognitive representation and revealed that categorization of presented object can be successfully recognized using recorded EEG signals when subjects view objects. Here, EEG signals in conjunction with a multivariate pattern recognition technique were used for investigating the possibility to identify conceptual representation based on the presentation of 12 semantic categories of objects (5 exemplars per category). Using multivariate stimulus decoding methods, surprisingly, we demonstrate that how objects are discriminated from phase pattern of EEG signals across the time in low-frequency band (1-4 Hz), but not from power of oscillatory brain signals in the same frequency band. In contrast, discrimination accuracy from the power of EEG signals has significantly higher than the performance from phase of EEG signal in the high-frequency band (20-30 Hz). Moreover, our results indicate that how the accuracy of prediction changes between various areas of brain continuously across the time. In particular, we find that, during the object categorization task, the inter-trial phase coherence in low-frequency band is significantly higher than other frequency in various regions of interests. This measure is associated with decoding pattern across the time. These results suggest that the mechanism underlying conceptual representation can be mediated by the phase of oscillatory neural activity.