Dynamical activities of primary somatosensory cortices studied by magnetoencephalography
Dynamical activities of primary somatosensory cortices studied by magnetoencephalography
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DOI：
10.1103/physreve.80.051906
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发表时间：
2009-11-01
影响因子：
2.4
通讯作者：
Kishida, Kuniharu
中科院分区：
文献类型：
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作者：
Kishida, Kuniharu
本文介绍了一种利用脑磁图研究大脑皮层动态活动的反馈系统传递函数的盲辨识方法。在5 Hz周期性正中神经刺激中检查躯体感觉活动。在本文中，我们将尝试两个仔细的预处理程序的识别方法，以获得初级躯体感觉皮层之间的脉冲响应。体感诱发场的时间序列数据通过使用T/k型（分数）去相关方法的盲源分离获得。通过逆问题将体感诱发场的时间序列数据转换为初级体感皮层电流偶极子的时间序列数据。在消除确定性周期性诱发波形后，得到了它们的电流偶极子的起伏。一种基于反馈系统理论的识别方法，用于从初级躯体感觉皮层的电流偶极子的波动中估计反馈模型中的传递函数。它们之间的动力学活动通过传递函数及其脉冲响应的波德图来表示：在识别的传递函数的脉冲响应中发现通过胼胝体的约30 ms的时间延迟。
A blind identification method of transfer functions in feedback systems is introduced for examination of dynamical activities of cortices by magnetoencephalography study. Somatosensory activities are examined in 5 Hz periodical median nerve stimulus. In the present paper, we will try two careful preprocessing procedures for the identification method to obtain impulse responses between primary somatosensory cortices. Time series data of the somatosensory evoked field are obtained by using a blind source separation of the T/k type (fractional) decorrelation method. Time series data of current dipoles of primary somatosensory cortices are transformed from the time series data of the somatosensory evoked field by the inverse problem. Fluctuations of current dipoles of them are obtained after elimination of deterministic periodical evoked waveforms. An identification method based on feedback system theory is used for estimation of transfer functions in a feedback model from obtained fluctuations of currents dipoles of primary somatosensory cortices. Dynamical activities between them are presented by Bode diagrams of transfer functions and their impulse responses: the time delay of about 30 ms via corpus callosum is found in the impulse response of identified transfer function.