Performance measures for ERP signal extraction methods

A critical problem encountered in evaluating methods that extract event-related potentials (ERPs) from single-trial electroencephalograph (EEG) signals is the inadequacy of available performance measures. Here the authors analyzed two standard performance measures, Normalized Mean Squared Error and correlation, and a lesser used measure, dynamic time warping (DTW), and explored the conditions under which they provide misleading results. The authors´ experience to date leads them to recommend the use of a combination of a shift-tolerant, correlation-based measure, such as DTW, and a robust Normalized Mean Square Error measure