Başar E, Demiralp T, Schürmann M, Başar-Eroglu C, Ademoglu A
Institute of Physiology, Medical University Lübeck, Lübeck, Germany.
Brain Lang. 1999 Jan;66(1):146-83. doi: 10.1006/brln.1998.2029.
On the basis of a systems theoretical approach it was hypothesized that event-related potentials (ERPs) are superpositions of stimulus-evoked and time-locked EEG rhythms reflecting resonance properties of the brain (Başar, 1980). This approach led to frequency analysis of ERPs as a way of analyzing evoked rhythms. The present article outlines the basic features of ERP frequency analysis in comparison to ERP wavelet analysis, a recently introduced method of time-frequency analysis. Both methods were used in an investigation of the functional correlates of evoked rhythms where auditory and visual ERPs were recorded from the cat brain. Intracranial electrodes were located in the primary auditory cortex and in the primary visual cortex thus permitting "cross-modality" experiments. Responses to adequate stimulation (e.g., visual ERP recorded from the visual cortex) were characterized by high amplitude alpha (8-16 Hz) responses which were not observed for inadequate stimulation. This result is interpreted as a hint at a special role of alpha responses in primary sensory processing. The results of frequency analysis and of wavelet analysis were quite similar, with possible advantages of wavelet methods for single-trial analysis. The results of frequency analysis as performed earlier were thus confirmed by wavelet analysis. This supports the view that ERP frequency components correspond to evoked rhythms with a distinct biological significance.
基于系统理论方法，有人提出假设，即事件相关电位（ERP）是刺激诱发的和时间锁定的脑电图节律的叠加，反映了大脑的共振特性（巴萨尔，1980）。这种方法导致了对ERP进行频率分析，作为分析诱发节律的一种方式。与ERP小波分析（一种最近引入的时频分析方法）相比，本文概述了ERP频率分析的基本特征。这两种方法都用于一项关于诱发节律功能相关性的研究中，该研究记录了猫脑的听觉和视觉ERP。颅内电极位于初级听觉皮层和初级视觉皮层，从而允许进行“跨模态”实验。对适当刺激的反应（例如，从视觉皮层记录的视觉ERP）的特征是高振幅阿尔法（8 - 16赫兹）反应，而对不适当刺激则未观察到这种反应。这一结果被解释为暗示阿尔法反应在初级感觉处理中具有特殊作用。频率分析和小波分析的结果非常相似，小波方法在单次试验分析方面可能具有优势。因此，早期进行的频率分析结果得到了小波分析的证实。这支持了这样一种观点，即ERP频率成分对应于具有独特生物学意义的诱发节律。
