Distinguishing low frequency oscillations within the 1/f spectral behaviour of electromagnetic brain signals.
Distinguishing low frequency oscillations within the 1/f spectral behaviour of electromagnetic brain signals.
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DOI：
10.1186/1744-9081-3-62
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发表时间：
2007-12-10
期刊：
影响因子：
--
通讯作者：
Sonuga-Barke EJ
中科院分区：
文献类型：
--
作者：
Demanuele C;James CJ;Sonuga-Barke EJ
已被公认的是，测量的电磁(EM)脑信号的频谱显示功率随着频率的增加而减小。这种频谱行为可能导致难以在脑电和脑磁图(EEG和MEG)信号频谱中区分与事件相关的峰值和正在进行的脑活动。这可能会成为一个问题，特别是在分析低频振荡(LFO)时--低于0.5赫兹--目前在与癫痫发作或注意缺陷多动障碍(ADHD)等特定病理有关的信号记录中观察到，在睡眠研究中等。在这项工作中，我们提出了一种简单的方法，可以用来补偿这种1/f趋势，从而实现频谱正常化。该方法包括在进一步的数据分析之前通过微分器对原始测量的EM信号进行滤波。将所提出的方法应用于各种示例性数据集，包括甚低频脑电记录、癫痫发作记录、脑磁图数据和诱发反应数据，表明该补偿过程提供了一个平坦的频谱基础，在该基础上可以清楚地观察到与事件相关的峰值。研究结果表明，提出的滤波器是分析生理数据的有用工具，特别是在揭示极低频峰方面，否则可能被EEG/MEG记录中固有的1/f频谱活动所掩盖。
It has been acknowledged that the frequency spectrum of measured electromagnetic (EM) brain signals shows a decrease in power with increasing frequency. This spectral behaviour may lead to difficulty in distinguishing event-related peaks from ongoing brain activity in the electro- and magnetoencephalographic (EEG and MEG) signal spectra. This can become an issue especially in the analysis of low frequency oscillations (LFOs) – below 0.5 Hz – which are currently being observed in signal recordings linked with specific pathologies such as epileptic seizures or attention deficit hyperactivity disorder (ADHD), in sleep studies, etc. In this work we propose a simple method that can be used to compensate for this 1/f trend hence achieving spectral normalisation. This method involves filtering the raw measured EM signal through a differentiator prior to further data analysis. Applying the proposed method to various exemplary datasets including very low frequency EEG recordings, epileptic seizure recordings, MEG data and Evoked Response data showed that this compensating procedure provides a flat spectral base onto which event related peaks can be clearly observed. Findings suggest that the proposed filter is a useful tool for the analysis of physiological data especially in revealing very low frequency peaks which may otherwise be obscured by the 1/f spectral activity inherent in EEG/MEG recordings.
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影响因子：
3.3
作者：
Achermann, P;Borbely, AA
通讯作者：
Borbely, AA
影响因子：
3.3
作者：
Campbell, I. G.;Higgins, L. M.;Feinberg, I.
通讯作者：
Feinberg, I.
影响因子：
4.7
作者：
Ferri, R;Rundo, F;Stam, CJ
通讯作者：
Stam, CJ
DOI：
10.1017/s1472928803000074
发表时间：
2003-04-01
期刊：
Thalamus & Related Systems
影响因子：
--
作者：
Penttonen, Markku;Buzsaki, Gyorgy
通讯作者：
Buzsaki, Gyorgy
影响因子：
20.6
作者：
KESHNER, MS
通讯作者：
KESHNER, MS