Department of Mathematical Informatics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
Neuroimage. 2010 Jan 1;49(1):415-32. doi: 10.1016/j.neuroimage.2009.07.045. Epub 2009 Jul 29.
We propose a framework for signal analysis of electroencephalography (EEG) that unifies tasks such as feature extraction, feature selection, feature combination, and classification, which are often independently tackled conventionally, under a regularized empirical risk minimization problem. The features are automatically learned, selected and combined through a convex optimization problem. Moreover we propose regularizers that induce novel types of sparsity providing a new technique for visualizing EEG of subjects during tasks from a discriminative point of view. The proposed framework is applied to two typical BCI problems, namely the P300 speller system and the prediction of self-paced finger tapping. In both datasets the proposed approach shows competitive performance against conventional methods, while at the same time the results are easier accessible to neurophysiological interpretation. Note that our novel approach is not only applicable to Brain imaging beyond EEG but also to general discriminative modeling of experimental paradigms beyond BCI.
我们提出了一个用于脑电图(EEG)信号分析的框架,该框架将特征提取、特征选择、特征组合和分类等任务统一在一个正则化经验风险最小化问题下,这些任务在传统方法中通常是独立处理的。通过凸优化问题,特征可以自动学习、选择和组合。此外,我们还提出了正则化器,它们可以诱导出新型的稀疏性,从而为从判别角度可视化任务期间的受试者的 EEG 提供了一种新的技术。所提出的框架应用于两个典型的 BCI 问题,即 P300 拼写器系统和自我调节手指敲击的预测。在这两个数据集上,与传统方法相比,所提出的方法表现出了竞争性的性能,同时,结果更容易进行神经生理学解释。请注意,我们的新方法不仅适用于 EEG 以外的脑成像,也适用于 BCI 以外的一般实验范式的判别建模。