基于小波网络的事件相关电位单次扫描分析——方法学基础与临床应用

Single-sweep analysis of event-related potentials by wavelet networks--methodological basis and clinical application.

作者信息

Heinrich H, Dickhaus H, Rothenberger A, Heinrich V, Moll G H

机构信息

University of Goettingen, Germany.

出版信息

IEEE Trans Biomed Eng. 1999 Jul;46(7):867-79. doi: 10.1109/10.771199.

DOI:10.1109/10.771199

PMID:10396905

Abstract

OBJECTIVE

Trial-to-trial variabilities in event-related potentials (ERP's), which are neglected by investigating averaged ERP's, can be important to establish group-specific effects in clinical studies. Single ERP responses have to be analyzed to quantify these variations. In order to overcome the disadvantages of existing single-sweep estimators, we have developed a new procedure based on wavelet networks (WN's) and applied this novel approach in a study concerning attention deficit hyperactivity disorder (ADHD) in children.

METHOD

WN's represent signals as a linear combination of wavelet nodes, i.e., components characterized by time-frequency features related to the wavelet transformation. In single-sweep analysis, each wavelet node is restricted to a specific region of the time-frequency plane during the recursive WN training process. This is achieved by means of tapering and bandpass filtering with Gaussian functions which are automatically adapted and closely related to the Morlet basis wavelet. The time course of a single event-related response can be reliably estimated. Furthermore, the WN method automatically provides well-defined parameters for single event-related responses, respectively ERP trial-to-trial variabilities.

RESULTS

In a psychophysiological study on ADHD using auditory evoked potentials (AEP's), latency and amplitude parameters extracted from averaged ERP's did not reveal any significant differences between 25 control and 25 ADHD boys. In contrast, interesting group-specific differences could be established by WN single-sweep analysis.

CONCLUSION

WN single-sweep analysis can be recommended as a sensitive tool for clinical ERP studies which should be applied in addition to the investigation of averaged responses. INDEX TERMS: Attention deficit hyperactivity disorder (ADHD), event-related potentials, single-sweep estimation, single-sweep parameterization, time-frequency method, wavelet networks.

摘要

目的

事件相关电位（ERP）的逐次试验变异性在临床研究中对于建立特定组效应可能很重要，但在研究平均ERP时被忽视了。必须分析单个ERP反应以量化这些变异。为了克服现有单次扫描估计器的缺点，我们开发了一种基于小波网络（WN）的新程序，并将这种新方法应用于一项关于儿童注意力缺陷多动障碍（ADHD）的研究中。

方法

WN将信号表示为小波节点的线性组合，即具有与小波变换相关的时频特征的分量。在单次扫描分析中，在递归WN训练过程中，每个小波节点被限制在时频平面的特定区域。这是通过使用高斯函数进行加窗和带通滤波来实现的，这些高斯函数会自动调整并与Morlet基小波密切相关。单个事件相关反应的时间进程可以可靠地估计。此外，WN方法会自动为单个事件相关反应以及ERP逐次试验变异性提供明确的参数。